Moe

Here is the new content that has been added:

Mitsubishi HC5500 LCD Projector
Toshiba 52HL167 LCD TV
Integra DTC 9.8 Processor
Oppo DV-980H DVD Player
Da-Lite Designer Contour Electrol High Power
HTPC – Home Theater Personal Computer
Playstation 3 Blu-Ray & Games
Media File Server (unRAID)
Harmony One Remote
Buttkicker & Buttkicker Accessories
Home Theater Room
Next Generation Remote Control Extender

I hope you all like it!

Cheers,
Moe

This CRT primer/FAQ was written by Curt Palme. Curt is a reseller of CRT projectors and one of the most knowledgeable guys that I know when it comes to CRT projectors. If you want to see what projectors he has for sale or would like to get on his mailing list please visit his website. www.curtpalme.com

CRT Projectors

Most of the projectors that I sell through Sound Solutions come from the US government and large corporations like Boeing, Disney and IBM that are liquidating the large 100-250 lb CRT projectors for the smaller 10 lb DLP and LCD models. These surplus CRT projectors date from 1988 to 1999, and most of the surplus units I get still have lots of life left in them. The ones that I scrap go into my parts stock

Most of the projectors that I sell go into home theatres, but pubs and sports bars do still purchase these from Sound Solutions. The following is my opinion and attempt to clarify the strengths and weaknesses of CRT, LCD and DLP projectors, and my attempt to clear up some of the myths surrounding CRT projectors. Again, the points and opinions that I offer below are my own. Like trying to get identical opinions from two car salesmen (no offense!), another CRT tech may completely disagree with comments I make below. My opinions come from having seen pictures and problems of almost every video projector model sold in North America. I have seen strengths and weaknesses in picture quality, ease of service (and getting parts), and common faults that occur with each brand and specific model. As I am an independent service rep, I have no ties to any manufacturer. (Should any manufacturer’s rep read this and take me to task on anything, the offending words were written by someone else!..:-)

Why CRT Projectors?

CRT projectors have been around since the dawn of television. An early electronics magazine that I have from the 1950’shows a large B/W video projector capable of projecting a 20′ wide image onto a wall. I have seen and operated an ancient tube chassis 3 gun 1000 lumen projector from the 1960’s that was used for the first Wrestlemania in 1986. Not a great picture, but at the time, an entire arena full of people paid $20.00 each to see Hulk Hogan duke it out on that projector.

Those of you that have seen a CRT projector in person will agree on one thing: they are large and heavy beasts. The lightest CRT projector weighs about 50 lbs and the heaviest that I have seen is about 250 lbs. There’s no getting away from the weight due to the glass picture tubes and the three lenses that these units require. Typical dimensions are about 24″ X 18″ X 12″ for a small projector, and a larger unit can be 40″ X 32″ X 16″.

Thanks to misinformed (and high commission ) LCD and DLP sales people, many myths surround the ‘mystique’ of the CRT projector. These include:

• expensive and short tube life
• CRT’s need constant adjustment
• CRT’s never give a good picture
• You need to call in a tech every time you need to adjust it.

As of this writing, CRT projectors still give the best quality image for a home theatre. The overall sharpness, focus, lifelike flesh tones and three dimensionality of the image still cannot be duplicated by any other type of video projector. To summarize the strengths and weaknesses of each type of projector:

CRT Positives:

• Excellent image quality
• No pixelation
• Excellent black levels
• Excellent flesh tones
• Long tube life
• Best $/hour performance ratio
• Relatively inexpensive to purchase used
• Most models are significantly quieter than LCD or DLP

CRT Negatives:

• Large
• Heavy
• Tubes are expensive to replace when they wear out
• Not as bright as current LCD or DLP models
• Do require maintenance and ‘tweaking’ from time to time
• Not ‘plug and play’
• Require a complete set up for a change in screen size

LCD/DLP Positives:

• Small and light
• Simple 2 adjustment set up (plug and play)
• No drifting or alignment of projector
• Decent flesh tones on DLP
• Less pixelation on DLP than LCD
• Easy to change bulbs
• Recent models are significantly brighter than CRT

LCD/DLP Negatives

• Some are objectionably noisy for home theater use
• Short bulb life (1000-2000 hours typically)
• Expensive bulbs ($300-$500 USD)
• Noticeable pixelation (LCD only)
• Poor flesh tones on LCD
• Poor black levels
• Edge artifacting on most images
• Built as disposable units, you’re not likely to get these repaired out of warranty
• Many bulbs are not available 5-6 years after the model has been discontinued
• Rainbow effects from DLP’s can give some people headaches

Yes, there is a time and place for all types of projectors. It would appear that LCD technology has hit its peak about 2001-2002. Most manufacturers appear to be producing DLPs now more than LCD, and it is argued that the technology that will go one step better than CRT has not been invented yet.

If you are looking for a small portable and easy to set up projector for computer use, LCD or DLP are the way to go. There are literally thousands of models out there that are available on eBay or elsewhere. Keep in mind that the life span of any particular model seems to be about 6 months as the DLP and LCD race for technology improvements continues, so any model is replaced after about 6 months. There are numerous companies that have gone out of business making parts hard to get for certain models and makes, plus many bulbs are obsolete and are simply not available. Currently many manufacturers are offering 2000, 4000 and even 6000 hour bulbs to compete with the typical 10,000 hour life of a CRT tube. The problem is, many of these bulbs lose their brightness over time, and so the white areas of an image of an LCD or DLP projector may turn yellowish or other colors due to a lower light output of an aging bulb. I’ve been told by manufacturers’ reps that typically the light output of a bulb goes down by 20% at the half life point. This also means that the light output is no longer pure white, so your whites (hickey
ice!) turns yellow and the color spectrum changes significantly before the bulb dies. Depending on how picky you are depends on when you change the bulb.

As of the update to this document (Dec 2003), I have seen a number of LCD and DLP projectors come through my shop for repair. As stated above, these small < 10 lb projectors run very hot as the bulb is in very close proximity to the main circuit boards. While some of these projectors have come out of sports bars that do not clean the air filters and thus the internal temperature increases significantly and shortens bulb and set life, the fact remains that these small projectors simply cannot be serviced the way CRT projectors can. Digital projector circuit boards are treated the way a sound or video card is dealt with in your computer: Do not repair the board, throw it away and install another one. The problem is, unlike a $50.00 sound card for your computer, a video processing board can run almost as much as a replacement projector.

I’ve seen time and time again where I’ve checked into the availability of a replacement bulb for a > 5 year old digital projector, only to be told that they are no longer available. Therefore, if you’re shopping for a use digital projector, buy a spare bulb for it now while it is available, and keep the air filters in the unit clean.

While only a handful of CRT models are still being manufactured as of 2003, there are so many available parts, modules and used projectors that parts availability (with a few exceptions) is not a problem for even 15 year old models.

If you don’t mind the large case that houses a CRT video projector, some occasional ‘tweaking;’ and the best picture for a home theatre, then keep reading, as CRT is for you!

CRT Basics

A CRT projector works on the same principles as your home TV does, with a few differences. Most video projectors do not have a TV tuner built in, so you need a VCR or satellite dish as your channel selector. The sound is routed through your home stereo or surround sound system rather than through the speakers built into the projector.

The video image is formed on three picture tubes, each of which produces one of the primary optical colors. High voltage within the set is required to excite the electron beam within the picture tube, which then generates light output when the electron beam hits the phosphor surface of the tube. The red, blue and green images are then aligned (or ‘converged’) on the screen to form one color integrated image.

The main components of the video projector are the picture tubes. These are three tubes that produce a high amount of light on the phosphor surface which is then
projected through lenses onto the screen. Myths surround these picture tubes too. Here are the basic truths:

1) The life of most picture tubes is rated at 10,000 hours by the manufacturer. It is very rare that a picture tube will fail from one use to the next, although this is possible. Most often, the tubes will simply wear out over time, but many tubes can still be used at the 10K hour mark. Depending on the make and model, the blue tube usually wears first, then the green, then the red in last place. Usually, red tubes are useable well past the 20K hour mark. I have found that in CRT projectors rated over 800 lumens that the green wears first, then the blue, with the red again lasting the longest.

It is my opinion that the manufacturers came up with this 10,000 hour point due to the fact that after 10,000 hours, the picture quality will be compromised with regards to focus, picture quality and brightness. The fortunate thing is, the change in picture quality is so gradual that many people use their projector well past the 10,000 hour mark before changing the tubes. If you have ever been into a sports bar and seen a CRT projector that has pink hockey ice and a puck that is so out of focus that you cannot see it, you will be watching a projector that has in excess of 15-20K hours on it.

The good news is, a projector tube does not really wear if no light is projecting out of it, as it is the phosphor surface that wears generally, and not the electron gun of the CRT. So you can have a projector running for 10,000 hours with no light output out of it, and still have the equivalent wear on the tube of about 500 hours.

The bad news is, a tube wears faster with a higher contrast and brightness setting, so always run a projector at as low a setting as possible.

Another negative is, CRT projectors are very susceptible to static images that can burn themselves into the phosphor surface in as little as 1000 hours. This is why I have to junk a lot of projectors that come out of static image computer installations. I have had CRT projectors that came from railroad control centers with little railroad tracks permanently burned into the face of the tube, which are then projected along with the video image you are trying to view. This makes a moving video image impossible to watch.

As indicated, it is the phosphor surface that wears on a CRT tube. This phosphor is sprayed on the inside face of the tube, and cannot be repaired once burned or damaged. Over time, the phosphor becomes discolored and this results in decreased focus and light output. An imbalance in light output of the three tubes results in poor colors, and a pure white image is no longer capable of being produced.

Fortunately, the tubes do not wear evenly. In the projectors that I have worked on, either the green or blue tubes start to show wear first, with the red being a distant last. Blues and greens can show slight wear at as low as 2500 hours, reds typically last at least 20,000 hours. This makes complete tube replacement not
necessary, thus lowering the overall price of overhauling a set.

The final point at which someone decides to retube a projector lies with how picky a person is about the overall picture. To put it in perspective however, 2
hours of CRT viewing per night is equal to only 730 hours per year. At the rate that used CRT projectors are being sold for, it is not worth retubing a projector in my opinion, depending of course on how much you have into the set. A ‘freebie’ can always be worth retubing.

2) CRT sizes

For all intents and purposes,. CRT’s come in three sizes; 7, 8, and 9″. Yes, some Sony 7″ tubes have a useable 5.5″raster, but we’ll get to that later. So, assuming the three sizes, the larger the tube size, the more resolution the projector tube will be able to display as the picture that is being projected onto a large screen starts from a larger tube surface. In general, a larger tube will also produce more brightness.
Naturally, a larger tube also costs more to make, which is why 9″ projectors are expensive to buy and expensive to retube.

In general, most video only and entry level data grade projectors are 7″. Mid grade projectors use 8″ tubes and the top of the line are 9″.
3) Video vs Data grade

All video projectors are usually called video projectors, however a higher end projector will also display data grade (higher resolution) signals than the regular video signal that is sent from a VCR or DVD player.

A standard North American video (NTSC) video signal consists of 525 horizontal lines that make up the TV image. These 525 lines do not change whether you are watching a 14″ TV or a 10’screen. This is why many larger pictures look grainy, as the scanning lines become very visible on even a 33″ regular TV that is in good condition, and much more noticeably so on a projection TV.

A data grade video projector will accept (usually) an HDTV signal, a line doubled signal, a computer signal via the high resolution RGB inputs, as well as a regular video signal. HDTV or line doublers insert an additional scanning line in between each of the 525 lines of a standard video signal, thus filling in the space between the scanning lines. Note that while true HDTV does actually send more video information to the projector, a line doubler is averaging the video information of adjacent scanning lines, and does not improve the quality of the basic video signal. Thus as with computers, garbage in, garbage out. Start with a good video (or S-video) signal, and a line doubler will be of great benefit to improve the basic video image.

Note that a video projector has to scan twice as fast for a line doubled signal as compared to a standard video signal. A standard video signal scans at a horizontal frequency of 15.75 Khz, so rounded up, a line doubled signal needs 32 Khz scan rate. The maximum scan rate of a CRT projector can be found in the model’s specifications.

HDTV broadcasts 1080 scanning lines which are interlaced (alternate lines are projected, so 540 lines are being projected at during any one ‘field’ of video information, so HDTV requires a 36 Khz scan rate, or something just over line doubling.

Line triplers and quadruplers are also available, and require signals of 48 Khz and 64 Khz respectively. In my opinion, a lot of people can get hung up on specifications, and for most home theatre applications, a scanning frequency higher than 64 Khz is not required. Many high end data grade projectors originally designed for CADD applications or flight simulation can take signals up to 135Khz, but I do not think you’ll ever use frequencies this high in a home theater application.

Video input Connections

There are four types of analog connections that a video projector might have. Video, S-video , RGB and component.

Most CRT projectors have a video or S-video input connector that will accept what’s called a composite video signal. This is the RCA or S-video jack that’s found
on the back of most consumer electronic products. Note that most commercial grade projectors will have a BNC connector for the video connection on the input jack panel. This is a higher grade connector than the consumer RCA jack on the back of a DVD player, and Radio Shack sells a BNC to RCA adapter that will convert the connections. One trick is to use RG-6 cablevision cable as your video cable connection to the projector. That way you can run the video cable up to about 300 feet without loss of the video signal. Simply buy an RCA to F (cablevision connector) adapter at the video source end, and get a second adapter at the projector which is a BNC to F adapter. Then run your cablevision wire between the two.

Due to a B/W and a chroma signal being run separately within an S-video cable, the general recommended length of S-video cable is limited to 30 feet or less. Longer runs will show that the B/W and color images will not overlap completely on the screen, and the color portion of the signal can lag the B/W one by 1/4″ on the screen. I’ve seen this happen in one of my own installations, and the only cure is to use a shorter S-video cable (or buy a very expensive S-video signal booster with adjustable phasing controls on it).

Most data grade video projectors will use an RGB, RGBs or RGBHV signal going from the source to the projector. The RGBHV signal uses 5 cable runs from the source
and the projector, one for each primary color, and one each for the horizontal and vertical sync signals. Some older formats use four cables, one for each color and one for both the H and V sync signals, and even older formats run the sync signals along with the green video signal. All line doublers, triplers and scalers that I have seen can switch between RGB, RGBs and RGBHV signal formats on their output.

With the high grade video cable available today, you can run up to 100′ of high resolution RGB signals without additional booster amplifiers. Over 100′ usually will require some form of RGB amplifier in the high definition line.

The introduction of the component signal format has caused more confusion and frustration than any other signal format. Sometime in 1994 (I’m guessing), some brilliant engineer decided that the decades old RGB industry standard for commercial and industrial video was not good enough for the consumer industry, and thus the component format was invented. Even though the three wires that are colored red, green and blue for the component signal would indicate a plug and play connection to a CRT projector’s RGB input, a component signal and RGB signal are NOT compatible. If you connect a component signal to an RGB input, you’ll only get a green image.

In order to make a component signal compatible with an RGB input, you need to buy what’s called a TRANSCODER.. A transcoder will convert the component signal to an RGB one. These transcoders are available online for under $200.00 USD. Note that most CRT projectors do not have a component input. Several models like the Sony D 50, G 70, G 90, Barco 701s and 708 do have component inputs along with RGB connections.

Note also that a very few DVD players have RGB outputs and some HDTV boxes may be switched between component and RGB outputs, while some only have component outputs. Check your source material for compatibility with a CRT projector.

The latest addition to the somewhat confusing types of signal on the market is called the DVI connection. It is a true digital connection and was introduced to prevent unauthorized duplication of video software. I do not believe that there are any CRT projectors on the market that accept a DVI connection from a signal source, although there are some DVI to RGB converters available.

Signal switching

Since we’re in the area of various signals that will connect to your projector, it becomes obvious that you may need a variety of switchers to handle these signal sources. You might have:

• Camcorder (video, S-video, component)
• Video game (video, S-video, component)
• Video tape (video, S-video)
• Laserdisk (video, S-video)
• DVD (video, S-video, component or RGB)
• HDTV (component or RGB)
• Computer (RGB)

You have to plan carefully how to switch these various signals. Most line doublers or scalers will have a variety of inputs to select between your sources Some doublers and scalers will have an RGB pass through ,so that a HTV signal will bypass the signal processor and feed directly to the projector (you cannot line double an HDTV signal which is already line doubled). External video switchers are made by companies like Inline or Extron, and many of these high grade switchers can be found on eBay.

Note that obviously many A/V surround sound receivers have video switching built into them, but beware that many of the video switching found in these receivers is substandard and can actually noticeably degrade the video signal quality. It’s always best to use a commercial grade video switcher. For those wanting all switching to be done with the push of one or two buttons, many of these video switchers may be RS-232 controlled by a control system.

Analog vs digital convergence

As previously described, the images of the three CRT’s need to be precisely aligned on the screen to form a single picture. This is done by first physically aligning the projection tubes, and then adjusting up to 300 points on the image so that all three CRT images line up exactly.

While this sounds like a daunting task (thus one of the appeals of LCD or DLP), in most cases the full alignment can be completed without extra test equipment,
and nothing more than a screwdriver. Even a first time CRT owner should be able to get about 95% of the capability of a projector out of the set by completing
the alignment themselves without the help of a tech. Those not interested in learning the procedure can hire a tech to align or converge the projector for them. The last 5-10% of the image quality is done by a CRT tech, or those CRT owners that find pleasure in ‘tweaking’ the image from time to time, to compensate for tube wear or convergence drift. Note that these tweaking adjustments take only a few minutes to complete, but of course there are those CRT owners that tweak more than they watch the projector.

Analog convergence is found on older or entry level projectors, and typically consist of 30 to 50 controls under the cover of the projector to align the geometry and
convergence of the unit. This procedure is a little harder to learn than digital convergence, which is done via on screen menus that guide you through the procedure, and a wired or wireless remote control lets you go right up to the screen to perform exact convergence settings for an accurate picture.

While analog convergence is an older technology and a bit harder to learn, great deals can be had on projectors with analog convergence, and as long as the set was well built, I have not found that analog convergence drifts more than digital convergence.

Drifting convergence is usually as much due to a shifting earth’s magnetic field, physical jarring of the projector (vibration) as is due to drifting component values of the convergence board.

Mounting and Throw distances

All CRT projectors have a fixed throw distance for a set image size (width). Most projector use a throw distance of 1.5 X the width as measured to the lenses, so for an 8′ wide screen, the lenses need to be 12′ from the screen surface. The exception to this throw distance is the Zenith video projector line that use a throw distance of 1.2 X the width of the screen. This distance can be varied a bit via the height and width controls within the projector, but the idea is to use as much phosphor area of the tubes as possible to avoid premature wear.

The one exception of using too much tube phosphor area is if you buy a projector that has a bit of phosphor wear. If that is the case, the wear area of the phosphor will be a bit less bright than the virgin area. If you project an image onto partial virgin phosphor area, the edge(s) of the image that are into the virgin area will be slightly brighter than the worn area, and an uneven picture will result. The trick to get an acceptable picture from a worn tube is to project the new image within that slight wear area, so that only worn phosphor is used. This may mean shrinking the image down a bit, or moving the projector a bit further back from the
recommended throw distance.

All CRT projectors may be used in the floor or ceiling mounting mode, front or rear projection. As most projectors have a substantial weight to them, it is obviously important to safely mount the projector to ceiling studs. The other option is to leave the projector on the floor and build it into a custom coffee table or other cabinet. Leave enough room for the projector to get proper ventilation if you are building it into a cabinet.

If a throw distance is not possible due to a room layout, it is possible to bounce the image off an optical grade mirror, thus shortening the distance between the
projector and the screen. I have heard of one enterprising individual that mounted a projector behind a couch and then bounced the vertically mounted projector off a mirror located above the couch on top a screen, so that the large projector would not be readily visible.

In general, the projector must also be level with the top or bottom of the screen. If the projector is floor mounted, it must be about level with the bottom of the screen, and if ceiling mounted, the projector must be level with the top of the screen. This can be varied by about a foot or so, but the convergence and geometry alignment allowances within the projector are limited and it is not a good idea to reach the maximum points on a bunch of these settings.

Screen sizes

There is no one perfect screen size for any projector. The die-hards say that one should never exceed a 7′ wide screen to get the perfect picture out of even a
9″ projector, but I used to use entry level 7″ video projectors at high school dances onto a 15’screen back in the mid 80’s with good results. Not a perfect picture, but completely watchable.

In general, I recommend between an 8′ and 10′ diagonal 4:3 screen for most home theatres and bars.

There is of course a catch with a video screen. Most DVD’s and HDTV material is in 16:9 widescreen mode, while most regular TV broadcasts and VHS tape are still in the standard TV 4:3 format. If you use a 16:9 screen, 4:3 images will be off the top and bottom of the screen, while a 16:9 image watched on a 4:3 screen will have blank space top and bottom of the screen. For those that have the room and budget, I recommend a fixed 16:9 screen permanently attached to the wall, while a second 4:3 screen may be lowered in front of the 16:9 for regular TV viewing.

CRT projectors do not have the capability to convert 16:9 into 4:3 images and vice versa. What you feed into a projector is what it will produce on the screen. Many line doublers or scalers have the ability to convert a 4:3 image to project within a 16:9 screen, so that the height of the image remains constant, but the 4:3 image will then be smaller than the wide 16:9 format screen. Note that a 16:9 screen will use less phosphor area of a CRT tube than a 4:3 screen. If you set up a 4:3 image
within a 16:9 screen, even less phosphor area is used, so it will depend on how many hours a year you watch either format and if you plan on changing tubes
down the road on your projector as to how you set up your projection screen. Generally speaking, you will most likely see some 4:3 wear within a 16:9 screen
after about 4000-5000 hours of use. Conversely, I would estimate that you would see some 16:9 wear within a 4:3 screen after 5000-6000 hours of use.

Screen Gain

Commercially available screens come in various screen ‘gains’, i.e. how much light they reflect back at you. Generally, CRT’s are best suited for screen gains 1.8 or
less. Higher gain screens tend to develop ‘hot spots’, so that sections of the image look brighter than another, or the viewing angle of a high gain screen may be limited. That’s fine if you alone are watching the projector. But if a group of friends are over to watch sports, the ones off axis to the screen will get a lower brightness level.

Most of the screens that we sell are Draper 1.3 gain, and they have worked out fine in all applications. Da-lite and Stewart are also popular screen manufacturers.

High gain screens are usually also known as glass bead, and will not work properly with CRT projectors. These are the screens also used for movie and slide projectors, so if you have an old tripod screen gathering dust that you want to use for a CRT projector, you’re better off letting it continue to gather dust and spring for a new matte white A/V screen.

Note that if you find a used screen, and do not know if it is glass bead or not, run your fingernail over the surface of the screen. If it feels smooth or like canvas, then it is fine. If it feels like sandpaper, then it is a glass bead and cannot be used.

CRT Brightness

There is no question that CRT projectors require a dim or dark room for proper viewing. While the image will look best in a pitch black room, a low level light may be on without detracting from the image. Fluorescent lights are very bad for a video image as is sunlight or any light coming in from windows. Neon signs such as bar signs tint an image terribly, and often a bar must relocate such a neon sign when we install a projector.

In general, most CRT projectors put out a minimum of 550 lumens, which is adequate for a 7-8′ screen. The brightest CRT projector that I know of has rated at about 1500 lumens, which was the Barco 1001, but tube failure was common on these and several other Barco models. I do not believe that an average home theatre needs more than 1200 lumens.

The larger the tubes surface, the more area there is to project an image on, and in theory the slower a tube will wear out. Naturally, the larger tubes are rated for more light output than a smaller tube, and thus a larger tube is driven harder than a small tube. Hence, all picture tubes last about the same amount of time.

ES vs EM focus

Most projectors made until about 1994 used an electrostatic focusing method. This consisted of one electronic focusing control as well as several magnets located
around the neck of the picture tube for focusing fine tuning. This was a perfectly acceptable method of focusing, and standard TV sets and non HDTV rear projectors still use this method of focusing today.

In about 1993-1994, Electromagnetic focusing was introduced. This consisted of the main electronic focusing as well as the magnets around the CRT’s, however an additional focus coil. was added around the neck of the picture tube. This allowed the electron beam to be focused more than with ES focus, and projectors with EM focus will allow specific areas of the screen to be focused independently. Found in all current mid to high end date grade projectors, and is desirable to have (but also adds to the price of a used projector).

7″ ES focus sets:

• Electrohome ECP series
• Barco 400,. 500, 600, 700, 701, 708
• NEC DP-1200, GP-3000
• Sony 10XX series
• Zenith PV 800, 810, 820, 830. PRO 840, 841, 851, 880, 895, 900, 900x
• AmPro 1500, 2000, 1100, 1200

8″ ES focus sets:

• Sony 12XX series (sometime referred as 7″ sets)
• Barco 800, 801, 801s

9″ ES focus sets:

• Barco 1000, 1001, 1101, 1500, 1600
• AmPro 4000

7″ EM focus sets:

• AmPro 2300, 2600
• Sony D 50
• NEC PG series sets (actually about 7 1/2″ )
• Barco Cine 7

8″ EM focus sets:

• AmPro 3300, 3600
• Barco 808, 1208, Cine 8
• Electrohome Marquee 8XXX series
• NEC PG Xtra, XG series
• Sony G 70

9″ EM focus sets:

• AmPro 4200, 4300, 4600
• Electrohome Marquee 9XXX series
• Sony G 90
• NEC 10 PG
• Barco 1200, 1209, Cine 9

Projector ‘Sweet Spot’

Each CRT projector model has what is known as a ’sweet spot’, depending on the tube size and construction, as well as the quality of the internal circuitry. Speaking in very general terms, it is possible to feed too much video information to a projector, so much so that the circuitry and the tubes cannot accurately process the large amount of video information fed to it. A less detailed picture results, and some loss of detail may be noticed if the ’sweet spot’ is exceeded.

For example, a 7″ CRT system with ES focusing is best suited for line doubling or tripling if the tubes are in good shape. Feeding a line quadrupled signal into one of these projectors will show less detail and a bit of smearing will occur on occasion.

The below settings are approximately what I have found are the best signal to be fed to the projectors. Naturally these findings are subject to interpretation, and your own experimentation is encouraged to find the picture that is best for you.

ES focus:

7″ tubes- line doubling or tripling

8″ tubes-line tripling

9″tubes- line quadrupling

EM focus

7″ tubes-line tripling

8″tubes-line tripling or quadrupling

9″tubes-line quadrupling and above

CRT tube replacement and rebuilding

There are many brands of CRT video projectors out there, however there are far fewer CRT tube manufacturers. The main four tube manufacturers are: Sony, NEC, MEC
(Panasonic), and Zenith.

Zenith and NEC only make tubes for their own projectors, and did not subcontract their tubes out to other brands. Sony and MEC make tubes for many other manufacturers.

Sony tubes can be found in:

• Barco-Electrohome ECP series
• Sony-Seleco
• AmPro 2000, 2300, 4000

MEC tubes can be found in:

• Barco
• Electrohome Marquee series
• Panasonic-AmPro – all but 2000, 2300, 4000

Some CRT tubes can be rebuilt. Rebuilding consists of stripping the old glass envelope of the electron gun, removing the worn phosphor from the inside tubes surface of the tube, recoating a new phosphor coating inside the tube and then installing a new electron gun on the neck of the tube. This is a very exacting process, in fact I understand that the rephosphoring machine is worth about $2 million dollars, so I know of only one company that rebuilds picture tubes in the US. This company can rebuild Zenith, NEC, MEC and some Sony tubes. 7 and 8″ rebuilt tubes are quite reliable, although I have had to return several rebuilt tubes that were out of spec. I have not tried any rebuilt 9″ tubes, although I understand that the rebuilding process has not been perfected yet (but getting very close).

Expect to pay somewhere between $500.00 to $800.00 USD per tube for a rebuild, and $750.00 to $3500.00 for a new tube, depending on the size and source of the tubes. Zenith tubes for video grade projectors are somewhat below the $400.00 USD mark per tube.

Specific CRT Projector information

The following is a summary of features and problems with specific CRT models as I have experienced them. The main four projector brands that I sell and that are on the market in general are Barco, Sony, NEC and Electrohome. Other brands are Zenith, AmPro, Seleco, Vidikron, Runco, GE, Knoll and Kloss. I will detail the less popular models at the end of this section

Automatic convergence

Several manufacturers (Electrohome, Barco and NEC) offered an option that automatically converges the blue and red tubes to the green, thus speeding up the set up time of a projector. Electrohome called their option ACON, whereas Barco called theirs the IRIS. NEC calls theirs ACAT. The option consists of a small camera mounted on the front of the projector, that sees the test pattern image, and automatically adjusts the electronic convergence parameters for you. This is useful if you do not want to learn how to converge yourself, but in my opinion while the camera units work well, you can always do a better job of converging manually. An ACON, IRIS or ACAT usually adds at least $300.00 USD to the price of a used projector and were $1500 to $2500 when new.

Barco

Barco projectors are made in Belgium, and are long known in the pro video industry as a very high end of projectors. I understand that Barco has recently archived a lot of specifications of discontinued models on their website. Barco is still one of two or three manufacturers making CRT projectors.

Barco started with video projectors around 1983-1984 with the Barco Vision, Barco Data and Vstar lines. I understand that the Vstar models were made specifically
for the airline industry and the all of the projectors that I have seen from this era have weak tubes and usually have numerous circuit problems due to their age. I do not actively sell projectors that are this old, although I do have the service manuals and some parts for these sets.

Barco then came out with the Barco 400 and Barco 600 video projectors. The 400 and 600 are very similar in design and performance. They use 7″ SD-187 Sony tubes with ES focus, have analog convergence, and scan up to 64 Khz (depending on the exact model number) with 600 lumens light output. Thousands have been sold, and many are on the surplus market. These projectors must be used in conjunction with either a little plug in controller module on the back of the projector, or with a Barco RCVDS 4 switcher unit that acts as a video selector and video to RGB decoder. Note that these two projectors usually only have the RGB inputs working despite the fact that they have video input connectors on the projector. The video card was an option on these sets, and hardly any of the sets I get in have had the video card
installed. Also, most of the surplus projectors do not come with the plug in controller or with the RCVDS 4 unit, so you may end up needing more components before you get a watchable picture.

Barco 1000, 1001, 1500 and 1600. These are a series of 9″ analog convergence projectors that Barco came out with from about 1989 to 1993. All very similar to the Barco 600 chassis, but used 9″ Sony ES focus tubes, called the SD-146A. A great picture when properly set up, but Barco drove these tubes quite hard, and sudden tube failures were common. These tubes are hard to find on the used market, and are insanely expensive if purchased new. 64 Khz scan rate, 1000 to 1500 lumens.

In around 1990, Barco came out with the 500 and 800 models. The 500 is a 7″ version of the 8″ Barco 800. The 500 put out 600 lumens, the 800 put out 825 lumens. The projectors have digital convergence which is very easy to set up, and lots of on screen menus to guide you through the setup procedure. ES focus on all of these sets.

In about 1993 Barco came out with the Barco 801. The 801 was very similar to the 800, but had an extra circuit called AKB that compensates for picture tube wear. Basically the same overall picture as the Barco 800. ES focus on this set as well.

There are two versions of Barco 500 and 800 as well as other Barco models. There are Graphics and Data models of most projectors. The Data models use hybrid lenses
and do not scan as high as the Graphics versions, which also have all glass lenses. The Graphics are somewhat more desirable, but in most cases the scan rate of the Data projectors is more than adequate for home theatre use.

The Data 500, 800 and 801 scan to 58 Khz, (line tripling), the Graphics scan to 92 Khz.

In 1992 to 1994 Barco had a model called the Barco 700 and 701. This was designed more for the home market as the case was small and very streamlined looking. 7″ Sony ES focus tubes, about 600-700 lumens, and scan rates varying from 36 Khz to 60 Khz depending on the model. This unit had digital convergence, and a very nice picture if the tubes are in good shape. This model was not as modular as other Barco modules, requiring the projector to be sent in as a whole when servicing was required.

A higher end version of the 701 is the 701s followed by the 708. The 701s and 708 used 1000 lumen ES focus Toshiba tubes, and both sets came with component inputs along with RGB, video and S-video.

In late 1993 Barco introduced a new series of video projectors, the 808, 1208, 1200, 1209, and 1101. The 808 and 1208 were 8″ tubes with the improved EM focus, the 1101, 1200 and 1209 used 9″tubes with EM focus. Many of these models also had Data and Graphics models, with varying scan rates, and all were rated at 1000 lumens or above. Digital convergence on all of these models and lots of on screen menus.

Depending on the production run, the 808 either used Sony or MEC tubes. The MEC’s are rebuildable and the Sony are not. The Sony tubes are at least $1800.00 USD each
to replace, the MEC’s can be rebuilt for $600.00 USD each.

All of these sets give an excellent picture and have been a popular seller when I get them in. I get far fewer 9″ projectors in, but the 808 and 1208 are usually in stock.

The Barco 808 was made until about 1998, and has been replaced with the Barco Cine 7 and Cine 8. I have not worked with these projectors as I have never had any in on the used market yet. Very high end projectors though.

Barco strengths/weaknesses

In general, the Barcos have held up very well, other than the 1XXX series as noted above. Barcos are very modular, and about 98% of the components can be changed out without picking up a soldering iron. Most Barcos have a series of diagnostic lights within the chassis that make it easy to narrow down the problem area of a projector if it fails. I have serviced and repaired many Barco projectors via email or phone, with about 80% of the projectors being repaired the first time I send out refurbished boards.

Barcos are known to develop bad solder connections, specifically in the main power supply area. The Barco 500, 800 and 801 have the unique problem that if a certain solder connection fails on the power supply, all three tubes can be burnt instantly. Once the solder joint is repaired however, the problem never appears. I make a habit of resoldering all solder connections prior to selling these sets, and any power supply sent to me for repair has all connections resoldered as well..

Barco parts are insanely expensive from Barco themselves, however thanks to the large amount of projectors on the surplus market, several resellers such as myself
have a large inventory of rebuild modules and other parts in stock at a fraction of the original purchase price. I sell all parts on an exchange basis; you send me back the defective module so I can rebuild it and sell it at a later date.

Barco projectors with digital convergence are very easy to set up for convergence, and the manuals are very well written.

Sony

Sony basically was one of the pioneers of flat screen front projection TV’s. Sony made a series of wooden box KP-XXXX in the early to mid 1980’s that were designed to be projected onto a 6′ curved screen, and later these could also be used on a flat screen. Video only projectors, and most had a speaker and TV tuner built in. Very reliable sets, but I have not seen one in years.

Sony came out with their first flat screen CRT video projector in about 1983-1984 called the VPH-722. Later this model became the VPH-1020 and 2020, with little
differences between each of these. 7″ Sony Es focus tubes, analog convergence, 500 lumens or so. Convection cooled, very reliable, and occasionally I still sell these sets.

Between 1986 and 1996 Sony came out with a number of their 10XX series, including the VPH-1020, 2020, 1030, 1031, 1040, 1041, 1042, 1044, 1000, and 1001. With the
exception of the 1030 and 1031, these were all video grade sets, had analog convergence and had slight variations between the models. Some had S-video inputs, some had slightly brighter tubes, etc. etc. All very reliable sets, small footprint, and most had 2 or 3 small cooling fans in them. 600 to 750 lumens. In general, the higher the model number, the newer it was, but that changed with the introduction of the 1000 and 1001 in about 1995. I have no idea why Sony changed their numbering sequence…All of the above sets used Sony 7″ ES focus tubes.

The Sony 1030 and 1031 scanned to 26 Khz and 36 Khz respectively. With a small modification (I have not tried it), the 1030 could also accept a 32 Khz line doubled signal. Other than that, the overall picture was very similar to the rest of the 10XX series.

In 1990, Sony introduced a higher end model, the 1270. It came out in 5 different versions from 1990 to 1997, the 1270, 1271, 272, 1251 and 1252. All had slight
variations of the same basic chassis, and all used Sony 8″ ES focusing tubes. The 1270 had 650 lumens and 75 Khz scanning rate, the 1251 had 56 Khz scanning rate and 750 lumens, the 1252 had 61,5 Khz scanning rate and 750 lumens.

Each of these sets had 9 zones of fine convergence adjustments within the digital convergence settings.

The 1271 and 1272 had 65 and 92 Khz scanning rate respectively, and had 21 points of fine tuning, making these sets a bit more desirable for high definition installations. For all intents and purposes though, the entire 12XX line had identical pictures up to line tripling.

The Sony 1292 was introduced in 1995 as Sony’s flagship model. 110 Khz scan rate, 1200 lumens, 21 point digital convergence, and 9″ EM focus tubes. the basic image was very similar to the 12XX series, but the larger tubes and EM focus made for a razor sharp picture. Very large and heavy beasts.

The entire Sony 12XX line of projectors is known to be quite noisy due to the fans used to cool the projector. The 1292 is even noisier than the other models due to a total of 14 fans. A hush box is recommended for these Sonys if the noise bothers you.

In about 1997, Sony changed their projector lineup, and introduced the Sony D 50, D 70, G 70 and G 90 models, The D series was 7″, the G 70 was 8″ and the G 90 was 9″. All were significantly quieter than the 12XX series, had expanded digital convergence set ups, and gave an excellent picture. I have only to date worked with the D 50 and G 70, and they had stunning pictures.

Sony strengths and weaknesses:

The entire Sony lineup of projectors is known for their reliability, and failures during normal use are far and few between. The 10XX series and 12XX were not really designed as a modular set, and thus in field troubleshooting and repair is difficult. Almost all of these sets have to be sent to a service tech when a failure occurs.

Failures of fans have been seen, bad solder joints occur, and the odd component failure does happen, but in general Sony parts from Sony are less expensive than the
equivalent from Barco. Again, there are many surplus Sony projectors on the market, and good used parts are easy to find.

The Sony manuals are extremely well written and setup is almost as easy as the Barcos.

NEC

The first version of NEC CRT projector that I am familiar with is the 1988-1990 DP-1200. This is a video projector with ES focus 7″ tubes, and puts out 475 lumens. A fairly compact and reliable projector, this one is a challenge to set up and converge, but if you follow the instructions, you will get the hang of it. It uses digital convergence in conjunction with a wired or wireless remote control, and these remotes have been discontinued and are hard to find, whereas the projectors are relatively common. The tube life is exceptionally long in this projector model to the fact that they were not being driven very hard.

The GP-3000 and GP-5000 came out in 1990 to about 1992. The GP-300 was a 7″ ES focus and the GP-5000 was a 9″ projector. Both had digital convergence similar to the DP-1200, and they were rated at 600 and 650 lumens respectively. Again, a little hard to converge and set up, but they were a stable projector once they were set up.
the wired or wireless remotes are mandatory for the set up of this projector. Currently NEC does not support the above projectors, and all parts must be obtained on the surplus market.

In 1993, the PG series of projectors came out, this included the 6 PG, the 6 PG Plus, the 6 PG Xtra and the 9 PG, 9 PG Plus and 9 PG Xtra.

The base model 6 and 9 Pg were 7″ EM focus with 800 lumens, and digital convergence, The basic 6 PG only had RGB inputs; the video and S-video inputs required an optional video card. the 6 PG scans to 60 Khz, the 9 PG to 90 Khz. The 9 PG came with a point convergence card that allowed fine tuning of the convergence parameters. The 9 PG also came with the optional video and S-video card.

The 6 and 9 PG Plus had slightly higher scanning rates of 64 and 94 Khz, and had a higher video bandwidth for a slightly improved picture.

The 6 and 9 PG Xtra used different picture tubes that offered 1000 lumens instead of the 800 lumens of the basic model.

Again, the NEC’s needed the wireless remote to set the projector up. These are currently still available from NEC.

In late 1996 the XG series of projectors replaced the PG line. The XG models came out as the XG 75, 85, 110 and 135. The number within the model number indicated the max scan rate of the projector, so the XG-75 was 75 Khz, etc. True 8″ EM focus tubes, video, S-video and RGB inputs, digital convergence, and 1200 lumens. One of my favorite projector series of all time due to their great flesh tones.

Lots of convergence parameters to set up, which result in an excellent picture.

The XG-110 and XG-135 also came in a liquid coupled version, which is harder to find than the non LC version. The LC adds a layer of fluid between the tube surface and the lens, giving more contrast to the picture, but reducing the brightness slightly. These LC tubes are also more expensive than the non LC versions.

NEC strengths and weaknesses

All NEC projectors in general are very reliable, with the exception of the GP-3000 which are now known for sudden power supply failures. There is a custom chip in the GP-3000 power supplies that has long been discontinued, and when that chip blows, the power supply is a write off. Working supplies are hard to come by on the surplus market.

NEC in general used an outside vendor for all of their power supplies, and are therefore sold as a whole assembly from NEC. Fortunately, failures of other than the GP-3000 power supply appear to be rare.

The NEC PG and XG series occasionally has failures of the convergence and focus output board as well as the deflection board, but these boards are easily and cheaply repaired.

The phosphor appears to wear faster on the PG and XG series due to the high amount of light output from these sets, which is why I usually retube these sets prior to selling them.

In general however, NEC’s are an excellent bet as a used projector.

Electrohome

Electrohome is a Canadian based company and made two series of projectors (excluding the very early models), the ECP and Marquee lines.

The ECP line came out in about 1984 starting with the ECP 2000. This was a 32 Khz RGB projector only using an older style of Sony ES focus tube, and had a large optical system within the projector that combined the light output of all three tubes and projected to one large lens. Apparently there was a video input board available for the ECP 2000, but I have never seen one. This model is now considered obsolete, but complete working units can be found on eBay if you’re looking for spare parts.

After the ECP 2000 came the ECP 3000 and 4000. In fact, every model from the ECP 3000 and up is very similar, with circuit and specification changes differing somewhat. The basic look of all of these is the same.

The 3000 and 4000 used Sony SD-187 tubes, the same found in a number of Sony and Barco sets. ES focus, they were called 7″ tubes and have a 5.5″ usable phosphor area. The 3000 scanned to 55 Khz, the 4000 to 80 Khz. Both have digital convergence and were relatively easy to set up. Many of the components were on PC board modules, making field service simple. The ECP series is taller than most projectors, making ceiling installation difficult if the room does not have a lot of height to it. The ECP 3000 and 4000 were made from around 1988-1990.

The ECP 3100 and 4100 were made from around 1991-1994. These sets improved on the convergence software, and other PC board changes were made, Some boards are interchangeable throughout the ECP line, others are model specific.

The ECP 3500 and 4500 used brighter and newer Sony 07MS tubes for an extra 100 lumens brightness along with sharper focus. The focus boards that were notorious for drifting in the earlier ECP’s were completely redesigned (although it is a simple task to repair and modify the older boards), the 3500’s and 4500’s were made from about 1994 to 1997. These sets are still very popular and command a good resale value on the used market.

Marquees

Electrohome is still making their Marquee series of projectors. These came out in 1993 as a high end 8 and 9″ 1000 lumen EM focus projector. All have digital convergence, on screen menus, and work exceptionally well. The Marquee 8XXX series designates the 8″ model, the 9XXX the 9″ model.

The Marquee 8000 came out in 1993 to 1995. Versions prior to July 1994 had older software without an internal hour meter, the later ones improved and expanded on the internal menus.

The 8110 came out in 1996-1998 and furthered circuit changes and software. The 8500 came out in 1996 and is still a current model to my understanding. The light output was upped to 1200 lumens by increasing the high voltage.

The 9XXX series came out in 1995 (I believe) and used 9″ tubes. These sets provided better resolution than the 8XXX series. The Marquee 9500LC is the flagship model in the Marquee line, retailing for over $40K USD when new These sets are used as the industry standard for very high end flight simulators. Modular construction is used throughout the set for simple filed service for most failures.

The Marquee series come in an ‘LC’ version for both the 8 and 9″ versions, which improves contrast. These sets are hard to find, and go for a premium price, even with worn out tubes.

Strength and weaknesses ECP:

The ECP’s have had numerous problems with them, most of which are inexpensive to repair, but cause annoying downtime. These include: bad Dallas chips (the main memory of the entire projector) which should be replaced every 8 years or so, bad focus resistors in the earlier ECP’s, bad IC connections in their sockets and bad LV and HV power supplies.

The only real concern are the failure of the power supplies, which while rare, cannot generally be easily repaired as Electrohome subcontracted the supplies, and does not provide individual parts or circuit diagrams for them. When they fail, they must generally be replaced as an entire assembly. ECP’s are plentiful though, and some power supplies can be interchanged between models.

The ECP 3000 and 4000 are now about 12-13 years old, and are becoming unreliable with the above described problems. The later models are still a good bet as a small data grade projector.

Strength and weaknesses Marquees

Similar to the ECP’s, the Marquees have the odd power supply failure, and the high voltage power supply is a sealed unit which cannot be repaired unless you’re really lucky. These supplies are in demand, as many people want to stock a spare in case of a failure. Again, they do not fail often, and overall the Marquees have been reliable. Some of the 8500’s had a power supply design flaw, which would destroy tubes by supplying them with too much voltage. It’s best to check if an 8500 that you are considering has been modified to repair this design flaw.

I consider the above 4 brands to be the ‘top 4′ for used CRT projectors that we resell and service. Below are other brands that will sound familiar or that you should at least be aware of:

Zenith

Zenith came out with their entry level flat screen front projector in 1985, and at approximately $2500.00 retail, undercut their competitors like Sony by at least 50%. These were video only projectors, had crude analog convergence, but tens of thousands were sold from 1985- 1994, making them the most popular CRT projector ever for the sports bar and home markets. Various changes were made throughout the years, with the model numbers being: PV 800, 810, 820, 830, 840, and 851. Tuner models were also made in some years that incorporated 125 channel tuners and small stereo amplifiers for those people who did not want a complicated set up to watch a large screen picture. The final couple of models turned into very decent video only sets, with accurate convergence and very nice pictures for a very inexpensive price. All of these sets were convection cooled for silent operation.

In about 1996, the PRO 851 was replaced with a PRO 880, a completely redesigned video only set. This 880 had sharper tubes, digital convergence and an overall better picture than the earlier sets. The unit however was very difficult to converge until you learned how to do it, and made it difficult for the user to set up themselves.

Zenith also came out with a data grade version that scanned to 48 Khz , called the Pro 900. The early PRO 900’s had mis-designed power supplies and had 100% failure rate of these within 2 years. Zenith redesigned the set, and the PRO 900x solved the problems of the earlier PRO 900. A very nice picture from a 7″ tube.

Currently, Zenith is still making projectors, and rumor has it that Barco is actually manufacturing the top of the line Zenith set, the 1200, although Zenith Canada has stopped bringing in projectors, so I have not seen these.

Zenith Strengths and weaknesses

While Zenith made excellent sets with the exception of the 1989-1990 PV 830 which has premature CRT failure, service literature is scarce from Zenith. Even a set up manual is hard to find. Zenith relied on their large dealer network to service these sets, but many TV shops are unwilling to do service calls to sports clubs, and lack the knowledge to properly converge and set up a CRT projector.

Zenith’s policy is to do PC board swaps only, and in general do not sell parts for these boards. The upside is that replacement boards are cheaper than every other brand of set, and replacing an entire board is cheaper than spending the time to find the $10.00 chip or transistor that has failed. Without proper service literature available however, finding the right defective board the first time is the challenge..

All Zenith sets are 100 % modular, and should not require more than a screwdriver to service. I have serviced 100’s of sets in nicotine covered pubs and bars, and all models have stood up well. It’s common for me to retube these sets after a good 15,000 hours of service, only to have them last another 15,000 hours. A great bang for the buck. Many of these sets are in home theaters, and can be had at a good price from people upgrading to data projectors.

Zenith is discontinuing some modules and parts, but parts and service should be available for the life of most of these sets, thanks to the large number of these sets that have been sold in the past.

Zenith is still making CRT projectors, and the PRO 895 is being sold at attractive prices. Make sure you find a dealer that knows CRT’s though; many of these sets are being sold by electronics stores that cannot assist you with the installation and service.

AmPro

AmPro was a US made CRT series of projectors from 1984 to 1998 when they went out of business.. AmPro was known also as: ESP, Gretag Image Systems, and Esprit depending of the year of manufacture. In general, the picture quality was excellent out of all AmPro projectors, but have a somewhat lower than average reliability record. There are many Ampro projectors in the surplus market now, so parts availability is excellent, and great deals are to be had, as Ampros sell for less than the equivalent model from a company that is still in business. The image out of an Ampro is at least equal to that of the ‘big 4′ name brand sets, and are easy to set up.

AmPro made 7″, 8″ and 9″ projectors. The 7″ models were:

-1400, 1500- video only

-2000 D and G- data grade

-2300, 2600- EM focus data grade

The 8″ were:

-3300, 3600- 8″ EM focus data grade

The 9″ were:

-4000- 9″ ES focus data grade

4200, 4300, 4600- EM focus data grade.

All of the AmPros required a serial computer interface or a custom AmPro wired or wireless remote to operate and set up. Without either, the projector is useless.

Overall , however, many Ampros were sold, and they are plentiful on the surplus market. I was told that Ampro started because of NASA, and continued to be their largest customer.

Ampro Strengths and Weaknesses:

The biggest weakness of course is that the company is out of business. Factory support is nonexistent, and aftermarket parts specific to the AmPros are found only on the surplus market and from one or two companies consisting of ex-Ampro employees. . The upside is that Ampros generally sell for less due to this than equivalent Sony, Barco, NEC or Electrohome models.

Common faults with the Ampros are bad solder joints, and high voltage arcing can cause havoc with the microprocessor circuits. CRT socket cards are a common problem (repaired easily), but the HV power supply is made by the same company that sells them to Electrohome, and failures are usually only solved by replacing the entire supply.

Runco

One of the most common brands of consumer high end projectors is Runco. However, Runco is not a CRT projector manufacturer in the truest sense; Runco takes CRT projectors from Zenith, NEC and Barco, paints them black, and relabels them,. True, Runco has custom ordered stripped down Zenith PRO 900x projectors, installed a line doubler and changed components on the microprocessor board, but the specs of the projector by and large still remain true to the original Zenith chassis.

Runco has been a very successful marketing company, but parts pricing is up to 3 X what it would be from Barco and NEC or Zenith. Runco does make their own line doublers and other signal processors. Check out Runco projectors, then check out NEC’s Barcos and Zeniths. If the case style looks the same, it will be a set that was supplied by one of the larger manufacturers to Runcos specifications.

The upside is that while Runcos are expensive to purchase either new or used, their resale value does hold up. For example, I sell NEC 9 PG Extra projectors for around $3000.00. An equivalent used Runco 980 Ultra sold on eBay in March of 2002 for $7100.00.

Vidikron

Similar to Runco, Vidikron only ever manufactured one or two models. Electrohome made the bulk of their sets for them. Vidikron changed the case style, marked them up accordingly and sold lots to the high end consumer markets. See ‘Electrohome’ for their pros and cons. The original Vidikron projector was a video only 7″ ES focus set, and threw a good picture, comparable to the Sony 10XX series or Zenith Pro 851.

Seleco, GE, Knoll, Ultravision, Cinemabeam, and others

Seleco made a few of their own sets, I have only ever seen one, and as I could get no information on it, I scrapped it. I understand that they are a well respected company in Europe, but not well marketed and supported in North America.

GE never made their own sets, rather had sets made by Zenith, Panasonic and NEC. The cases were charcoal gray and overall were good sets.

Ultravision was a small company that rebadged Zenith projectors. I have no idea how many they sold, I have only ever seen one.

Cinemabeam- This was Runco’s first entry into the large screen projection market before they were known as Runco. These sets were made by Matsushita, and Runco added a wired remote to them. These sets were popular in 1984-1986 and are now considered obsolete.

“What’s best for me?”

This is a common question that I get emailed daily on, and the answer is that you really need to come up with some guidelines as to budget, and how important a home theater is to you. I generally tell people to budget $1.00 per hour of use for a projector. That covers the purchase price and any maintenance of the projector. Now naturally if you buy a retubed projector, you’d expect to get 10,000 hours of use out of the tubes, so that $1.00 per hour of run time should come way down, but if you figure on $1.00 per hour, you can easily decide whether it’s worth $3.00 to watch that 3 hour Survivor special or whether you’ll watch it on your good old 27″ TV.

Decide whether a home theater will replace you going out to the movies, or whether it will only be used a few times a month. IN general from known resellers online and on eBay, you get what you pay for. If you see two identical projector makes models from the same reseller, and one is a few hundred dollars more than the other,
you can bet that the more expensive one has tubes in better shape, or has some optional feature that brings the value of the set up.

I’ve outlined many of the parameters to consider above when deciding on a projector. Nothing beats seeing a CRT (or digital) projector in action, so seek out someone that has a unit installed, and take a close look to see whether you’d be happy with the picture. If you’re looking at a digital, view a brightly colored scene like an outdoor sports game, and also look at a dark movie to see whether the blacks are truly black and whether you can see rainbows in the dark scenes on a DLP unit. Check out the focus of an ES set vs an EM CRT.

An excellent resource for more information is www.avsforum.com. I’m in the CRT forum often, and there are many other forums that deal with signal processors, screens and source material that I’ve only quickly touched on above.

Generally speaking though, if you compare similarly spec’ed sets, such as comparing one 8″ EM focus set to another, as long as the sets are in the same overall condition, you will see some slight differences between makes and models. If you put 100 people in a room to compare these sets, you will get more or less an even split as to which is the favorite projector. You will not get 90% of the people pointing at one set saying that it’s the best or worst compared to the others.

Why buy from Sound Solutions?

Aha, here’s the small sales pitch at the end of the document!

There are thousands, no, make that tens of thousands of used CRT projectors available for purchase through eBay and various other outlets. Many people that sell on eBay obtain their projectors as part of large computer shipments bought as government surplus. Many of these resellers have no interest in the CRT projectors and will put them on ebay in as-is condition. While the odd one might be in perfect shape, chances are much more likely that they need some major repair work or tube replacement before these sets produce a watchable image. Sound Solutions buys these projectors in bulk and weeds out the wheat from the chaff. While we do sell ‘as is’ projectors occasionally for people that are looking for parts units, our projectors are tested carefully to ensure proper working condition to as close to factory original as possible.

While CRT projectors are going for a small fraction of what they were once sold new for, the replacement parts are still full retail from the manufacturer. It’s therefore not uncommon to buy a projector for a few hundred dollars, but then find out from the manufacturer that the power supply that the set needs costs $1500.00. Like buying a high end sports car, you can’t take a projector to a local TV shop (usually) for a $50.00 tune-up. Few people know these sets down to a circuit board level like we do, and we have the parts and service manuals to restore these sets to proper working condition.

In addition to thoroughly testing these sets, we replace a number of components that are prone to failure before selling these sets. Many of these parts are upgraded with a better quality unit to ensure a high mean time between failures. Sometimes the failure of a 50 cent part will wipe out that set of pristine set of CRT’s, so we ensure that these critical parts are new or in perfect working order before a set ships out.

Occasionally a set will get damaged in transit. We ensure that any shipping damage is dealt with immediately, as we all know, courier and trucking damage claims can take months to resolve, and that’s not a problem that you should get stuck with.

Sound Solutions maintains good relationships with other CRT resellers and suppliers, Should there be a rare time that we do not have a part in stock, we will buy a part or module from another supplier to ensure that your set is up and running as quickly as possible.

Sound Solutions carries a large part inventory. We estimate that we scrap two sets for every one that we sell.

Sales pitch over!..

That about does it for now. Feel free to email me with any questions or comments about areas not covered by this document. I’d be happy to
add to it as I have time.

Note last note: before you buy, ask questions, and take a close look at a well set up CRT system. Not everyone will buy CRT, but those that do appreciate the pictures that this ‘old’ technology projects, despite what the high commission ‘bulb’ projector salesmen may tell you..
Looking to buy a CRT Projector? Then check out my CRT Projector store!

Curt Palme
curt@curtepalme.com

Check out these great deals on CRT projectors at ebay

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SVGA VGA MONITOR/LCD/PROJECTOR CRT CABLE MALE CORD 10FT US $7.19 End Date: Wednesday Mar-17-2010 20:57:51 PDT Add to watch list

Sony VPH-D50 CRT video projector- 1080i US $900.00 (0 Bid) End Date: Thursday Mar-18-2010 11:21:39 PDT Add to watch list

Sony VPH G90 CRT video projector HDTV 1080p! US $4,500.00 (0 Bid) End Date: Thursday Mar-18-2010 11:21:52 PDT Add to watch list

VDC/Electrohome 9500 Ultra CRT video projector 1080p! US $7,500.00 (0 Bid) End Date: Thursday Mar-18-2010 11:22:04 PDT Add to watch list

Over there on the left you can check out all my equipment, some galleries, and some helpful guides for those of you new to the hobby. Below you will find my home theater blog of sorts. I will probably use this area for site updates, movie and DVD reviews, possibly some good home theater deals that I run across, and other home theater related news.

I hope you enjoy your stay, please feel free to leave comments or questions on any of my articles.

Moe

When I first got the projector home I was a bit worried, I’ve been a pretty die hard fan of CRT projectors for a while now and my two previous digital projectors, a Sanyo PLV-60 and an Infocus X1, while good for what I was using them for just didn’t stack up to my G70. I must say, after a quick setup or the 5500 I was extremely impressed. The picture looked great! One thing that immediately impressed me was the black levels. I put in the movie Cars and near the beginning of the movie there is a scene where they are introducing “Lightning McQueen” and they show him set against a black background and I the blacks were nice and inky black. Now don’t get me wrong, the black levels aren’t as good as they were on the G70, this becomes readily evident on really dark movies. Watching a movie like The Descent really shows the lack of true deep blacks on digital projector but the projector does a good enough job that it no longer bothers me. Compared to the G70 I do love the brightness, the ease of setup, the small size, the sharpness, the noise (more on that in a minute) all in all, the only thing I miss about the G70 is the true blacks.

One special thing to say about the Mitsubishi HC5500 is the noise. There flat out isn’t any. The projector sits a couple feet above my head when I am watching a movie and I just do not hear it. I don’t know how they do it but this projector is virtually silent.

When it came to mount my HC5500 I knew I was going to be in for a challenge. With sixteen foot ceilings I knew I wasn’t going to be able to do a ceiling mount which meant mounting it on the wall. I ordered myself Chief Manufacturing RPA-U Universal Projector Ceiling Mount and then I hit up Home Depot. I need to bring the projector about three feet away from the wall in order in order to get it the right size on my screen so at Home Depot I assembled together a series of pipes and fittings to do just that. I am really happy with the way it turned out, it looks a bit industrial but I think it works well in my loft. It’s also rock solid so I have no worries about it failing.

Overall I’ve been extremely happy with my Mitsubishi HC5500 LCD Projector. Compared to the G70 which it replaced it has it’s pros and cons but overall I, as much as I hate to admit it, I prefer the HC5500. If you’re in the market for a 1080P projector I can heartily recommend the the Mitsubishi HC5500, it’s a great little projector and the price doesn’t hurt the wallet too badly.

Mitsubishi HC5500 LCD Projector Specifications

ANSI lumens: 1200
Contrast (full on/off): 14,000:1
Light Engine: 1920×1080, native 16:9, 0.74″ three-panel inorganic LCD, Micro Lens, with 160W UHP lamp.
Video Compatibility: 1080p/60/50/24, 1080i, 720p, 576p, 576i, 480p, 480i.
Data Compatibility: Computer resolutions up to UXGA 1600×1200
Connection Panel: Two HDMI v. 1.3, one 15-pin VGA, one 3-RCA component input, one s-video, one composite, one 12V trigger, one 9-pin DSub serial port.
Lens and Throw Distance: 1.2:1 power zoom/focus lens with vertical powered lens shift. Throws a 120″ diagonal 16:9 image from 12.5 to 15.25 feet
Lamp Life: 2,000 hours, 5,000 hours in eco-mode
Warranty: Two years. Lamp warranty One Year or 500 hours, whichever comes first.

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Mitsubishi VLT-HC5000LP Lamp for HC5000 HC5500 HC6000 US $268.00 End Date: Thursday Mar-18-2010 6:45:23 PDT Add to watch list

MITSUBISHI Projector Lamp HC4900 HC5000 HC5500 HC6000 US $217.00 End Date: Friday Mar-19-2010 6:39:59 PDT Add to watch list

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I was trying to keep my budget under a thousand dollars and was hoping to keep that closer to seven hundred. I did tons of shopping around and watched deals for weeks. I was really hoping to get a 46″ TV but I was afraid I was going to end up with a 42″. I had a couple criteria as well, the TV had to have HDMI and be 1080P. Anyway, I was watching the deal sites like a hawk and then I saw an ad on TigerDirect.com for the Toshiba 52HL167, which is a 52″ model, for $999.96. I have a 32″ Toshiba TV in my bedroom that I’ve been very happy with, I did some quick searching around on the net for the Toshiba 52HL167 and it had generally favorable reviews. While I was expecting to get a 46″ or a 42″ TV I was really hoping to find something at least 50″ as I thought that was around the sweet spot for size considering my seating position, I just really didn’t think I’d find one in my budget. So, when I saw the Toshiba 52HL167 for under a grand I jumped on it.

I’ve been very happy with my Toshiba 52HL167, I think it puts out a great picture. Sure it’s not 120hz, but that hasn’t been an issue for me at all for either movies or games. It’s really nice having a “little” TV, it’s great for when I just want to have a TV on in the background, check something really quick, watch TV during the day, etc. I actually find myself watching it quite a bit, even when it’s dark enough to be using the projector. The projector always gets used for my favorite TV shows and movies but if I am just milling about watching TV at night often times I am just watching the TV.

Toshiba 52HL167 LCD TV Specifications

Key Features
Screen Size: 52 in.
Television Technology: LCD
Supported Resolution: 1080p
Supported Standards: HDMI
Form Factor: Widescreen
HDMI Type: HDMI Type A
Connector Types: Audio line-in, Audio line-out, Composite video/audio input, VGA input, Digital audio output (optical), HD component input, HDMI, S-Video input
TV Standard: HDTV
Sound Supported: Stereo
PC Compatible: Yes
HDTV Ready: Yes
Depth: 5.1 in.
Height: 31.2 in.
Width: 50.4 in.
Display Features
Aspect Ratio: 16:9
Display Resolution: 1920 x 1080
Widescreen Modes: Conventional 4:3, 16:9
Tuner Features
TV Tuner Type: Yes
Picture In Picture: Yes
Picture in Picture Type: POP
Audio Features
Audio Format Supported: Stereo
Additional Features
HDMI: Yes
Additional Features: Colorstream Component Video Input, Channel Labeling, Video Noise Reduction, Cinespeed, Ce-link, Dynalight, Colorburst, Pixelpure3g, On-screen Menu
Accessories
Remote Control: Universal remote control
Connectors
Connectors: Audio line-in, Audio line-out, Composite video/audio input, VGA input, Digital audio output (optical), HD component input, HDMI, S-Video input
HDMI: 3 x HDMI ( 19 pin HDMI Type A ) – rear
S-Video Connectors: 1 x S-Video input ( 4 pin mini-DIN ) – rear
RCA Connectors:1 x composite video/audio input ( RCA phono x 3 ) – rear, 3 x audio line-in ( RCA phono x 2 ) – rear, 1 x audio line-out ( RCA phono x 2 ) – rear, 1 x composite video/audio input ( RCA phono x 3 ) – side
Component Connectors: 2 x HD component input ( RCA phono x 3 ) – rear
Digital Optical Connectors: 1 x digital audio output (optical) ( TOSLINK ) – rear
Other Connectors Total (Free) / Type: 3 x HDMI ( 19 pin HDMI Type A ) – rear, 1 x VGA input ( 15 pin HD D-Sub (HD-15) ) – rear, 1 x digital audio output (optical) ( TOSLINK ) – rear
General Product Info
Exterior Color: Gloss black
Television Type:LCD TV
Weight: 89.7 lbs.
Dimension: 31.2 in. x 50.4 in. x 5.1 in.(HxWxD)

Focusing and aiming a CRT projector is a daunting task. It involves two projection systems which operate in series – optical and beam focus. Problems in one system make it difficult to see problems in the other. As a result, first time owners are sometimes at a loss as to which system is the problem. Add to that the need to astigmate the electron beam and adjust lens flapping (Scheimpflug) and the novice CRT setup can fall far short of the projector’s optimum.

Read through this document in its entirety before proceeding. At first, it will seem as though some steps are discussed in jumbled order. I have attempted to present this in sequence but one must perform tasks iteratively to achieve the final result. One revisits earlier steps because later steps make earlier ones easier to do more accurately.

Equipment Recommended:

• An external test pattern DVD such as AVIA or S&V HTT or a test signal generator provide the signals needed for alignment.
• A good pair of binoculars which can focus at SHORT distances is very helpful for critically observing the effect of adjustments.
• One roll of 3M brand blue easy release masking tape for marking the center of screen surface and edges. Do not substitute another brand of tape.
• Tape measure to find center of each screen edge
• Laser Pointer or CLEAN straight edge for finding screen center

Raster, Image Area and Internal Test Pattern Centering on Tube Face

Centering of the image on the tube phosphor surface is done by centering the raster on tube phosphor and then centering of the actual image within the raster. You should begin by hooking up and displaying a video source.

Raster – The area of the tube phosphor that is painted by the electron beam.

Normally, only part of the raster is actually used to produce the image. The raster can be seen by peering through the lens after turning down contrast nearly all the way and then raising brightness to make the normally black raster light up. This makes the entire raster light up dimly. It may be necessary to open the left, right, top, and bottom blanking controls to allow visualization of the entire raster. Size of the raster is adjusted using vertical and horizontal size (aka amplitude) controls. The rasters are best kept small enough to ensure active video image is never extended beyond or near the phosphor edges. Keeping at least 7 to 10 mm of unused phosphor on all edges helps prevent the catastrophic tube failure that will occur if active image is projected beyond or too close to the phosphor edges. Since the raster is usually larger than the actual image area and it is actually the energy of the image area that can cause damage, some installers will allow the raster to extend beyond the edges while still maintaining image area within the safe portion of the phosphor.

When viewed on screen, the leftmost portion of the raster is drawn first after the electron beam completes horizontal retrace. Looking into the projection lens the orientation is backwards. During the first portion of the horizontal movement the beam has not settled completely and one may see some waviness in the image if the extreme left edge of the raster is used. Some installers will intentionally displace the raster slightly leftward so the active image is displayed on the later, more stable portion of the raster.

Centering the raster is performed by use of centering magnets on the CRT necks just behind the deflection yokes. The centering magnets are a pair of rings with small tab handles. By rotating the rings relative to each other and also around the neck of the tube one can shift the raster about the phosphor surface. Most projectors also have electronic static position controls for fine adjustment of the raster centering. It is best to use minimal electronic correction to reduce strain on the convergence circuitry. One can do so by centering the electronic controls prior to centering the raster with the centering magnets. On some projectors (such as NEC XG’s), there are no centering magnets and raster centering is carried out purely with electronic controls for raster centering hidden in a service menu. Even on such machines it is reasonable to first center the user centering controls prior to setting the service menu raster centering controls.

Image Area – The portion of the raster which is actually used to display the video image

Within the raster, the active video image is displayed. The projector often has “position” or “image shift” controls which allow movement of the image within the raster. The name of this control varies from brand to brand. You can verify you have the correct control by making the raster visible and seeing if the image is moving about within the raster but the raster is not moving as you use the control. If raster moves as well as the picture, you are adjusting the raster position and not the image position within the raster.

Ideally, the image area is centered both vertically and horizontally on the phosphor surface. You can achieve this by first neutralizing the linearity controls and then centering the raster relative to the phosphor edges. Then center the image area within the raster edges. Once both are done, display a white field pattern from a calibration disc (AVIA, S&V Home Theater Tune-Up) and verify that the active is centered in the phosphor. We’ll cover this in greater detail later.

BTW, Don’t use an internal test pattern for checking centering as they are often not themselves centered relative to external signals unless you have also taken the steps described next in this note.

Internal Test Pattern Centering

Built in test pattern generators do not necessarily coincide with actual video signals in timing. They tend to be off center and not exactly scan locked to match a real signal. This means that making an internal test pattern look correct does not necessarily optimize the machine for a real signal. However, internal test patterns are handy and some machines like NEC’s actually require you to set their timing relative to the video signal and convergence systems to prior to other geometry and convergence adjustments. If you have a machine which allows adjustment of internal test pattern timing, it is possible to center the internal test patterns to coincide with the center of actual video signals. This is much easier to do if mechanical gun aim has already been accomplished. In the next section, mechanical gun aim will be covered so skip forward and do that. Then set internal test pattern centering (phase) as described below.

For example, the phase control of NEC projectors MUST be set before geometry and convergence adjustments when creating a new input memory. The phase control changes the timing of the internal test pattern generator and also timing of the convergence system relative to the video signal. Since you have already centered the gun mechanical aim and centered the image on the screen and phosphor surfaces, adjusting phase to make the internal generator centered on screen also centers it with the video image center. Adjust phase to make the center vertical line of the internal generator centered left/right on screen. Then adjust phase to make the deflection blip centered around the center vertical line. The blip shows the centering of the convergence system. If it makes it easier for you, display the internal center cross pattern rather than the crosshatch while adjusting phase. Ignore the odd shape of the lines, just concentrate on the position of the middle of the center vertical line and the blip.

Since there is no control to shift the internal test pattern vertically, the only way to achieve vertical coincidence of the image and internal pattern centers is the image position control. Once that is done, you may need to readjust projector tilt to get things centered on screen. Going through all gains you the option of using either internal or external test patterns with good accuracy.

One should strive to keep the image centered within the phosphor surface and leave at least 7 to 10 mm of unused phosphor all around the active image. Mechanical aim of the guns is easier to do when the image and rasters are vertically and horizontally centered on the tube faces. Further fine tuning of raster and image centering can be performed as well as centering of the internal test pattern generator once gun aim is accomplished.

Mechanical Gun Aim

If your projector has lens tilt rings, set them to factory spec for your projection distance before doing any aiming.

You must first mechanically aim the guns properly. Most CRT projectors have red and blue lens/CRT assemblies (aka gun assembly) capable of swinging left/right. Up/down mechanical aim is accomplished by altering projector tilt. These movements mechanically aim the center of all three guns so they converge at screen center. Typically four bolts accessible at the bottom edge of the gun assembly secure the gun. These are loosened to free the lens and gun assembly and allow left/right swing. Do NOT REMOVE all four screws. Merely loosen them. Check in your installation manual to verify which screws need to be loosened. Some projectors only have a few fixed swing angles which are secured by placing a locking screw through specific drill holes. Others allow infinitely variable convergence angle and are secured by placing the locking screw through an arc shaped slot instead of a hole. The green gun usually isn’t adjustable left/right so getting the projector centered and square to the screen during mounting is vital.

The guns sometimes stick in their prior position even when the screws are loosened. Controlled pressure can free a gun, but never force the guns because a sudden give way motion could snap a tube neck. One method of producing controlled pressure is to place some fingers between the lenses and gradually form a fist. This allows considerable pressure to be exerted without risk of sudden excessive motion. Once freed, just point each gun exactly and lock them in position. How that is accomplished comes next.

Marking Screen Center

Mark the your projection screen’s exact midpoint of each edge (top, bottom, left, right) with a triangle of 3M blue easy release. Then mark the exact center with a LIGHTLY applied triangle of the same tape. This tape, if left for less a few hours, should not mar a screen. At least it never has in my hands. I cannot say the same for other brands so I suggest no substitutes. Finding screen center can be accurately done using a laser pointer placed at one screen edge midpoint marker and bouncing the beam off the screen surface to make a spot at the opposing midpoint marker. If a laser is not available, a tape measure can suffice so long as care is take to avoid marking the screen with tape measure.

Aiming the Guns

The traditional method of setting mechanical aim is to display a center cross, center the cross in each phosphor and then swing the guns and tilt the projector to place the projected red, green, and blue crosses all at screen center. The problem with the traditional technique is the difficulty in judging when the center cross pattern is accurately centered on the phosphor. I prefer an alternative technique which is easier to visually judge ? centering using edges. Basically, this takes advantage of how easy it is to accurately judge evenness of the gap between test pattern edges and the phosphor edges.

Turn down contrast and display a white field pattern and shift the raster to make the edges of the pattern equidistant relative to the phosphor edges. Look into the lenses while doing this, not at the screen. You will need to do this for each gun. The pattern will be widest at the CRT bottom assuming ceiling mount. Adjust size and position left/right to assure the pattern is well clear of the phosphor edges and equally spaced from the edges at its greatest left and right extents. Adjust the pattern up/down to achieve even spacing for the top and bottom edges as well. Once that is done, the pattern is precisely centered left/right and top/bottom on the phosphor surface. All you need to then is mechanically aim the guns to project that centered pattern so its edges are centered relative to the projection screen.

Look at the top of the projection screen and examine the left/right relationship of the projected pattern edges and the screen edges. Swing the gun left/right to equalize the edge relationships. Don’t worry if the red and blue guns are not yet the same width. Just make sure the edges are balanced left/right for each gun. Lock the CRT’s into position. They are now precisely mechanically aimed left/right.

Next, pay attention to how the projected white field pattern is positioned vertically using just the green gun. You should have previously set the pattern so is centered up/down on the phosphor. Adjust projector tilt up/down to make the projected green white field edges equally balanced relative to top and bottom screen edges. Now for more explanation.

If you happen to know your center cross pattern is already precisely centered you can just use the center cross to aim the tubes. Unfortunately, the most accurate way I know of doing that is to pull the lenses off, center the cross on the phosphor while measuring with a ruler, then remounting the lenses. The white field pattern edge comparison method described above allows easy, accurate physical aim and centering on the phosphors without pulling the lenses. This also gives a subtle plus for the red and blue guns as I’ll explain later.

I know this method seems backwards, but balancing the edges of a white field pattern against the edges of the phosphor and then the projected edges relative to the screen edges achieves precise mechanical aim in an easy manner. The advantage to this method is basically the difference between having someone mark the middle of a piece of paper without aid of a ruler vs aligning a slightly smaller piece of paper so it is uniformly spaced inside the larger piece of paper. The latter is easier to do accurately.

Consider the off center red and blue guns. If you aim the actual center of the phosphor of those tubes to project at the center of the screen, you’ll note that the phosphor usage distribution is unequal left/right due to the throw angle. Graph it out and you will see that the farther half of the screen gets illuminated with a smaller area of phosphor. Ever notice how the side of the screen opposite the side of the gun is less well focused? This is part of the reason.

Centering a field pattern relative to the phosphor and then using those lit up edges to guide lens aim will actually place the red and blue guns so they are mechanically slightly off true center. The left lens ends up pointed slightly left of center and the right lens ends up slightly right of center. At first blush, this seems wrong, but this can actually be advantageous because it makes the raster usage, resolution, and illumination more uniform across the screen. Less horizontal linearity compensation and lens flapping are needed.

Now if you are a traditionalist and want the center of the phosphor actually aimed at the center of the screen, you can pull the lenses off, set the center cross with great precision and then use the projected center cross position to guide mechanical aim. This is the usual way things are done, but I present an alternative approach with some advantages.

You have now precisely aimed the gun assemblies. From now on, anything projected that appears centered on the screen is also appropriately centered on the phosphor.

Note: Mechanical Aim is Not Scheimpflug (Lens Flapping)

Novices confuse the two, but mechanical aim is not the same as lens flapping (aka Scheimpflug). Mechanical aim of the CRT/lens assembly is akin to taking a telescope and physically pointing it at something. Lens flapping adjusts the mounting angle of the end lens without changing the direction the telescope is pointed. Lens flapping doesn’t change the direction of aim (well just a little), but compensates for the planes of the screen and phosphor being non-parallel. If the lens were kept parallel to the phosphor surface, it would be impossible to focus throughout the screen at the same time. The flapping places the lens into a plane intermediate between those of the screen and phosphor and that makes global focus possible.

Rough Optical Focus

Now that mechanical aim of the guns has been done, it is time to do an initial, rough optical focus.

Display a crosshatch pattern. Adjust optical focus using the two knobs. The front most knob on the lens controls edge optical focus. The rear most knob adjusts center optical focus. Dial in center focus first. Then adjust the outer (front knob) focus to while watching the corner lines of the crosshatch flare inward and outward. Try to minimize flaring using the outer focus knob. Go back and forth between the two optical focus knobs to get both center in focus and outer edge minimally flared. Use of binoculars aids this process tremendously.

Rough Scheimpflug (Lens Flapping)

Once rough optical focus is completed, you can perform lens flapping. The following is primarily for projectors which have continuously variable lens flapping. For projectors with lens flapping rings, simply set the lens rings per the installation manual specified settings for your projection distance.

Display a focus pattern. Look ONLY at the center of the top edge. Adjust center optical focus to make that edge sharpest. Note the position of the focus knob. Pay attention to the center of the bottom edge. Adjust lens center focus to make the bottom edge sharpest. Is the lens center focus control in the same position as when the top was sharpest? If so, vertical flapping is correct. If not, adjust vertical flapping using a wrench. Note the wrench position when the bottom edge is focused vs top edge. Set the vertical flapping to put the wrench in exactly halfway between the two positions. Horizontal flapping is performed in an analogous fashion paying attention to only the left and right edges.

Now go back and refine center and edge lens focus. Once that is done you should have the lenses in fair optical focus and flapping. Advanced owners may consider the 3 x 5 card technique fine focusing technique presented later in this document for even better optical focus and Scheimpflug.

Phosphor Grain Optical Focus Technique for when the Electron Beam Has not been Focused Yet

Most people have difficulty deciding whether optical, beam or both kinds of focus problems are present, particularly if they have not already achieved good beam focus. Here is a trick for setting good optical focus without being confused by beam focus. You must have a good pair of binoculars which focus at a short distance to use this technique.

The phosphor surface of a CRT has an inherent grain pattern. Because this grain is visible and is exactly at the plane of light generation, one can use the grain to set optical focus independent of beam focus. A small piece of 3M easy release blue masking tape aids in keeping your eyes correctly focused on screen. Display a bright window pattern and intentionally defocus the electron beam to make the scan lines disappear. Adjust center optical focus while viewing the screen through binoculars. When optical focus is correct, the inherent grain pattern of the phosphor surface suddenly snaps into view. This is nearly impossible to see with naked eye, but binoculars make it readily evident.

Electron Beam Focus

The electron beam focus system in a projector can be a simple one such as in an electrostatic system or a complex dynamically varied magnetic focus system. Sharp electron beam focus is easier if optical focus has already been done. Be sure to perform an adequate first optical focus prior to fine tuning beam focus.

You have also seen the word “astigmation” mentioned in regard to beam focus. Astigmation further shapes the electron focusing lens beyond regular focus controls and is important for achieving maximal beam focus. However, it should be fairly well set at the factory and new comers to CRT setup are best advised to avoid attempting CPC magnet astigmation adjustments until they are more familiar with projection CRT setup. For this reason I will cover astigmation last in this document even though it should actually be performed PRIOR to electron beam focusing adjustments.

Focusing Lens Cap to Assist with Electron Beam focusing

The phosphor grain optical focusing technique largely eliminates the need for this trick, but I mention this for completeness. Some projectors come with a special lens cap having a central hole approx 1 inch in diameter. This is intended to reduce the aperture of the optical lens and allow examination of beam focus even when optical focus is not quite correct. Because the phosphor technique easily achieves good optical focus independent of beam focus, I recommend setting the optical focus using the phosphor grain technique rather than resorting to a focusing lens cap.

Electrostatic Beam Focus

Electrostatically focused CRT projectors have their electron beam focus adjusted using variable resistors aka pots. These adjust the charge on the focus lens for each gun. Focus controls are often housed together and marked as focus for each color gun. On that same housing may also be “screen” controls which adjust G2 voltage. It is easy to inadvertently adjust the screen controls while attempting to adjust beam focus. I recommend that the novice cover screen controls with a taped on piece of cardboard to avoid accidental adjustment while attempting beam focus.

Check Beam Astigmation

Display a dot pattern on the projector. Work with only one gun on at a time and set contrast to moderately high level. Binoculars are once more useful in observing the effects of your adjustments. As you vary the focus pot setting, notice how the dots change between the overfocused and underfocused directions of focus adjustment.

The overfocused state changes the dots into a central bright core with a halo around it. Ideally the bright central core is exactly centered in the halo. Also the dots should move very little as focus is adjusted between over and underfocused states.

The underfocused state changes the dots into a uniformly lit blob. Ideally the blob is perfectly circular in shape at screen center. It is normal for some deformation to be present at screen periphery.

If you find the bright core off center, the blob isn’t circular at screen center, or the dots move as you adjust focus, astigmation for that gun needs to be corrected. That is done using the CPC astigmation magnets on the neck of each gun. CPC magnet adjustments should only be handled by a technician or very advanced user. Great caution is required due to risk of electrical shock, death, and equipment damage. Novices should enlist the aid of a technician if astigmation problems are noted on an electrostatically focused machine. On electromagnetically focused machines, there are often safe user accessible astigmation controls, suitable for the non-technician.

Once correct astigmation is verified (or you have decided to live temporarily with poor astigmation), proceed with the actual focusing of the guns. On an electrostatic machine it is simple.

1. Display a fine detail focus pattern or a dot hatch pattern . Set contrast to a medium level.
2. View only one gun at a time and adjust that gun’s focus pot for best overall focus. It is often impossible to achieve perfect beam focus throughout the entire screen. The screen edges are particularly problematic. Should that be the case, weigh the screen center as most important for your compromise setting. That is where most film material will be sharply focused.

The blue gun electorn beam is usually left slightly underfocused to allow better grayscale tracking at higher light output levels. If you have light metering capability, that means underfocusing the blue gun enough to increase blue light output by about 20% over the fully focused state. Note that this does not mean the blue gun OPTICAL focus should be left blurred. Just the electron beam focus! They are not the same.

Electromagnetically Focused Projectors

EM focused projectors populate the pinnacle of projection CRT technology. These machines use a magnetic coil to focus their electron beams. This is often combined with a system for dynamically varying focus to achieve good center and edge focus. (This is also done on some electrostatic machines, but not with adjustability) The EM focused projector also usually has some form of dynamic astigmation controls to refine beam spot shape throughout the screen. These extra dynamic focus and astigmation controls allow very fine focus compared to electrostatic units, but more controls means greater effort to achieve final results. EM focus also induces some spiral geometry distortions which need to be counteracted. The novice can do it successfully, but more work is needed to get everything in order.

Fore and aft sliding of the focus coil and rotation of the dynamic astigmation coils are not covered in this document. Those are maneuvers safest left to experience hands.

EM focused projector typically include a remote operable control control for overall (aka center) beam focus. This is analogous to the focus pot in an electrostatic focused machine. An EM focused machine also usually provides additional controls for fine tuning beam focus at the image edges, corners or screen zones. These extra controls allow better edge to edge beam focus than just a fixed single focus control setting.

The EM focused machine also adds a mechanism for dynamically correcting beam astigmation for each portion of the image. Dynamic astigmation refines overall beam focus beyond that achievable with just static CPC magnet astigmation. Again a control is supplied for adjusting overall astigmation (center of screen usually) and other controls for each edge, corner or zone of the screen.

Check Static Beam Astigmation

The machine will usually have some sort of CPC magnet assembly for rough static adjustment of beam astigmation. If the CPC magnets are properly set, the dynamic astigmation system won’t have to work as hard to achieve good astigmation. For this reason, it is a good idea to verify and adjust the CPC magnets are properly set by neutralizing all the dynamic adjustments and then checking static beam astigmation. If the underlying static astigmation is flawed, the CPC magnets should be corrected prior to performing dynamic astigmation. The complete set of CPC magnets may not be present in a EM focused machine. Consult your service manual. Once static astigmation is done as well as possible with the CPC magnets, fine tune with the dynamic astigmation system.

Set all dynamic astigmation controls to neutral to eliminate the effects of the dynamic astigmation system.

Display a dot pattern on the projector. Work with only one gun on at a time and set contrast to moderately high level. Binoculars are once more useful in observing the effects of your adjustments.

As you vary the center EM focus setting, notice how the dots change between the overfocused and underfocused directions of focus adjustment.

The overfocused state changes the dots into a central bright core with a halo around it. Ideally the bright central core is exactly centered in the halo. Also the dots should move very little as focus is adjusted between over and underfocused states.

The underfocused state changes the dots into a uniformly lit blob. Ideally the blob is perfectly circular in shape at screen center. It is normal for some deformation to be present at screen periphery.

If you find the bright core off center, the blob isn’t circular at screen center, or the dots move as you adjust center beam focus, astigmation for that gun needs to be corrected. That is done using the CPC astigmation magnets on the neck of each gun. CPC magnet adjustments should only be handled by a technician or very advanced user. Great caution is required due to risk of electrical shock, death, and equipment damage. Novices should enlist the aid of a technician if astigmation problems are noted on an electrostatically focused machine.

Dynamic Astigmation

Once static astigmation has been adjusted with the CPC magnets, one can proceed with dynamic astigmation. Some projectors will automatically underfocus and overfocus the electron beam appropriately when astimation controls are engaged. If yours does not do so, manually set beam focus to be underfocused or overfocused as needed. See the later section on CPC Astigmation for details of over vs underfocused beams with regard to astigmation.

Display a dot pattern and set contrast moderately high.

Start with all astigmation controls neutralized (center, all edges, corners, or all zones).

Adjust center astigmation skew and height controls to make the center blob circular. The machine may also have dynamic equivalents of the 2 pole adjustment. Adjust that to make the central spot centered in its halo. The actually set of dynamic astigmation controls vary from model to model, but the sequence is to perfect the center astigmation first. Then do the edges and finally corners of the screen. Zones interact so go back and fine tune when done the first time.

EM Beam Focus

Once astigmation is completed, electron beam focus can be done while viewing a fine crosshatch or focus pattern. Again, start by neutralizing focus controls for center, edges, corners or all zones. Focus the center of the screen first. Then do each edge and finally the corners. This particular order allows the interaction of the edge controls to do some of the corner correction before using any corner adjustments. Once more, recheck overall beam focus and retouch as needed.

The goal of adjusting beam focus is not only to minimize electron spot size but also reduce the flare around the spot as much as possible. Any flaring will cause edge transitions to appear soft. You will create an overall sharper looking image by accepting a slightly larger spot size if doing so eliminates the flare. Overfocus the beam and then slowly back off the control to allow the flare to diminish. Leave the control at the point at which flaring just disappears. You may need to perform this adjustment with contrast turned up enough to show the flaring. This optimizes the projector for best sharpness but not necessarily best resolution. The dot size may end up slightly larger and reduce resolution, but the increased sharpness will usually make the overall image look better defined.

This concludes beam focusing for EM projectors. I have condensed the process. The reader will best find the particular controls for his machine in the service and setup manual for the machine.

3 X 5 CARD OPTICAL FOCUS TECHNIQUE

At this point in the process, both beam and optical focus should be excellent, but further refinement is sometimes possible.

Use a plain white 3 x 5 card for finding the exact focal distance of the projector. Do this by moving the card fore and aft in front of your screen to see at where a fine focus pattern is best in focus. If it is already exactly at the screen surface plane throughout the screen, then you are done. If it is more than 1 cm in front of or behind the screen do the following. And yes, this will temporarily undo the hard work done getting the phoshor grain sharp.

Display a fine detail focus pattern (internal focus pattern or S&V Home Theater Tune-Up) and intentionally overfocus the optics (rear lens control) so that the center is best optically focused about 2 cm short of the screen. This is in the direction that extends the lens barrel forward. Bringing the focal plane slightly short of the screen lets you more easily examine the focal distances throughout the image area. Check the focal distance for each screen edge by moving the 3 x 5 card back and forth in front of the screen. You’ll be able to see very accurately the distance at which things are best focused on the 3 x 5 card. Check if the distances are uneven between left/right (indicating a horizontal lens flapping error) and top/bottom (indicating a vertical lens flapping problem). Fine tune lens flapping to make the focal distances for top = bottom, and left = right. This is the time to fine tune lens flapping rings. The 3 x 5 card check is so precise that you’ll notice the flapping changes caused by uneven tension on the lens mounting screws.

Next, pay attention to how the left and right edge distances compare to the distance at screen center. They should be about equal between center and edges. If not, slightly adjust the inner and outer optical focus to bring both the edges and center to focus about 2 cm in front of the screen. Notice that I don’t have you check the screen corners. That is because there will almost always be a difference in the extreme corners and center and using the left/right edges gives a good compromise which preserves the central focus where the video image is going to be sharpest portion of a movie frame anyway.

At this point the optics are perfectly balanced in terms of Scheimpflug and inner vs outer lens focus. The next step is to shift the entire optical plane back onto the screen surface. Make tiny movements of the rear lens focus knob while repeatedly checking the optical focus position with the 3 x 5 card. One thing to consider is that you probably did all this with the projectors lens hood off and the lenses are a little cooler than normal. As the lenses warm up, their index of refraction decreases, the lens mounts expand, and the focal plane can move slightly inward or outward. You should recheck the focal plane when the optics reach normal operating temperature an hour or so after the lens hood and hushbox are closed. Also, recheck 24 hours later and compensate for mechanical settling.

If you use the 3 x 5 card for final optical focus, you’ll note that it is so sensitive an indicator that even the slight shift of the lens while tightening the focus knobs will be detectable. Focusing a projector is an iterative process in which improvement in either optical or beam focus enable finer observation and adjustment of the other focus system. Patient and diligent technique is needed to achieve maximal sharpness of both optical and beam focus systems. Expect a great deal of exercise moving between screen and projector using this technique.

Perfected optical focus means that even better beam focus may be possible. Revisit beam focus and fine tune as appropriate.

Only AFTER both optical and beam focus are perfected should you do final work on geometry and convergence can proceed. Otherwise, geometry and convergences changes wrought by focus adjustments will upset a hard gained geometry and convergence setup.

Speaking of which, the next steps in projector setup would be

• Rough geometry and convergence
• Grayscale calibration (with possible blue gun defocusing)
• Final geometry and convergence

– Advanced Setup Technicians Only –

CPC Magnet Adjustment of Beam Astigmation

Warning!!!!! Novices and non-technicians are warned to avoid performing astigmation CPC magnet adjustments. Adjustment of CPC magnets should ONLY done by advanced setup personnel. Improper technique will render focus impossible. High voltage shock and tube neck fragility are also significant hazards during CPC magnet adjustment!!!!

Electron beam focusing lenses are not perfectly uniform. Also, the direction of the earth’s magnetic field can cause the beam to enter the lens off center. Astigmation of the beam fine tunes the lens uniformity and centers the beam as it enters the lens. This allows the beam lens to create a small electron spot with minimal flaring. Poor astigmation can make good electron beam focus impossible.

Static electron beam astigmation is carried out using CPC magnets (called Color Purity Control for historical reasons) on the tube neck and/or electronic astigmation controls. If both CPC magnets and electronic “dynamic” astigmation controls are present, it is best to let the CPC magnets do most of the work and have the electronic astigmation system merely fine tune the effects. One must neutralize the electronic astigmation controls prior to adjusting CPC magnets.

CPC magnets are arranged as pairs of rings about the end of tube neck near the socketed drive board. They should not be confused by the much more forward raster centering magnets just behind the deflection yoke. Projectors don’t always have the full set of 2, 4, and 6 pole CPC magnets. CPC magnet assemblies vary in appearance and mechanical design. Sometimes the ring pairs have a small knob allowing one to adjust the angle between the two rings of a pair. More often one merely sees tabs with which to manipulate the rings. The CPC have 2, 4, or 6 magnetic poles, but don’t confuse that with the number tabs on the rings. One cannot actually see the poles. By varying the angle between the two rings of a pair (moving tabs in opposite directions or twisting a little knob) one varies the intensity of the effect. Rotating a pair about the axis of the tube neck (moving tabs in same direction or twisting little knob in opposite direction) changes the directionality of the effect. If all three sets of CPC magnets are present, the rearmost is the 2 pole (centering). The middle is the 4 pole (ovalness). And the most anterior (if present) is either non-functional or a 6 pole correction (triangularity).

I’ll reiterate since this seems to confuse some people….

Intensity: The amount of effect that a magnet ring pair creates. For instance if you consider the two pole magnet pair, you can make the rings cancel each other out or augment each other by varying the rotation of the two rings relative to each other.

Directionality: The orientation of the net magnetic effect. If you spin a ring pair TOGETHER around the tube neck you spin the direction in which the poles affect the electron beam. Notice that this minimally changes how the poles cancel or reinforce each other. Spinning the pair together merely lets you vary the direction in which that magnet ring pair squeezes or expandes the beam.

Spinning a pair together changes the direction of the effect, but making the two rings of a pair spin in opposite directions changes the amount of their effect.

Because the factory performs CPC magnet alignment, shipping can shift controls, and end users are not expected to make these adjustments, the CPC magnets are usually held in place with some silicone adhesive. This must be removed carefully. Very cautious picking at the adhesive with fingers will usually free the controls. Do not mechanically stress the tube necks!

Again, neutralize all electronic astigmation controls prior to working with CPC magnets. On projectors which lack separate electronic astigmation controls, perform CPC and electronic astigmation while the highest scan frequency to be used is displayed.

I assume you know how to change the electron beam focus and don’t get that confused with optical focusing.

The 4 Pole (middle) CPC magnets affects ovalness of the electron beam lens. Adjust this while displaying a dot pattern with contrast set moderately high. Intentionally UNDER focus the electron beam making the dots into uniform blobs. Adjust the 4 pole magnets to make the center blob as perfectly circular as possible. Physically walk up to the screen to judge shape. Turning the small knob or moving adjustment tabs in opposite directions alters the amount of ovalness. Spinning the 4 pole rings around the axis of the tube neck changes the direction of the ovalness axis.

The 2 Pole (rear) CPC magnets centers the electron beam in the electron beam lens. Adjust this while displaying a dot pattern while contrast is moderately high. Intentionally OVER focus the electron beam making the dots into a flare with a bright central core. Turning the small knob or moving adjustment tabs in opposite directions alters the amount of deflection. Spinning the 2 pole rings around the axis of the tube neck changes the direction of deflection. Make the bright core centered in the flare.

The 6 Pole adjustment is also done with the dots pattern in under focus. If the 6 pole works (it may not do anything) it creates a triangular astigmation change. Use it to correct any residual triangularity which you could not correct using the 4 pole.

Go back and forth between the 2 and 4 pole adjustments to get things right. As a final check, carefully watch the dots as you go from under to over focused. The dots should stay almost motionless as you vary the beam focus. If they move, redo the 2 pole adjustment.

Once CPC magnets are set, fine tune using electronic astigmation if available.

You will have to redo raster centering after adjusting the CPC magnets. If working on the blue gun, you’ll probably want to leave the electron gun underfocused enough to make its light output measure about 20% higher than its fully focused state to improve grayscale tracking at higher light output.

Since very few companies sell CRT projectors any more and brand new ones are ridiculously expensive you are best off buying one used. One of the best places to look for used CRT projectors as well as parts for your CRT projector is on Ebay. Check out these great deals on CRT projectors at Ebay.

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Choosing the right screen for your home theater can be a major ordeal. It is often hard to view the actual screen that you are interested in so you have to rely on manufacturer claims and the opinion of other users. You can sometimes get screen samples from screen manufacturers but these are often so small that it is hard to accurately assess the screen materials from them.

There is also a lot of strange terminology that goes along with buying a screen that confuses a lot of people new to home theater; I know it confused me. The focus of this guide is going to be on getting you to understand what criteria you should look for in a screen material depending on the type of your projector and how you have it mounted, the lingo when it comes to screens, and to understand the pros and cons of different types of screens.

Selecting the Right Material

The main criteria that will help you determine the type of screen you should look for are the projector type, the brightness of your projector, the ambient light of your viewing room, the size and shape of your room, where you have your projector mounted, and your viewing distance.

Projector Type. Your choice of screen material will be dependent on the type of projector that you are using. Screen manufacturers have developed specially formulated screen materials that best compliment the type of projector that you use whether it be CRT, DLP, LCD, etc.

The Brightness of Your Projector. Depending on how bright your projector is, measured in ANSI lumens, will determine the size of your screen and the material choice for your screen. For instance, if you have a dim projector, you may not want to make your screen too large otherwise the resulting image would not be bright enough.

Ambient Light Considerations. Your best room will have complete and total light control; of course this isn’t always possible. Different screen materials have different properties when it comes to ambient light, especially ambient light that falls directly on the screen. Some screens are excellent at rejecting ambient light while others are not. Of course screens that are good at ambient light rejection have some tradeoffs as well.

Room Size and Setup. Ideally everyone in your theater will be within a viewing angle of 30 degrees from either side of the center of the screen. If your room needs a wider viewing angle than this look for a screen material with a wide viewing angle.

Projector Placement. There are a few different places that you can place your projector and all of them can benefit from a certain type of screen. If your projector is ceiling mounted, for instance, you will want to use a diffusion style screen or a reflective style screen but not a retroreflective style screen. And if your projector is rear mounted you will need to use a rear projection style screen.

Viewing Distance. One thing to take into consideration when you are figuring out the size of your screen is to figure out how close you will be sitting to it. There are several different schools of thought here. The SMPTE standard recommends a minimum viewing angle of 30 degrees for movie theaters; this standard also translates well for home theaters. THX also has their own set of standards for movie theaters to attain a THX certification. For THX standards the back row of the theater must have at least a 26 degree viewing angle but they recommend a 36 degree viewing angle.

As an example my screen is 87″ wide; in order for me to meet the SMPTE standard, my maximum viewing distance would be 13.6 feet. For me to meet the THX recommended distance, my maximum viewing distance would be 15.7 feet, with a THX recommended viewing distance of 11.2 feet.

Here is a great link to an online calculator to help you figure out viewing distance. Viewing Distance Calculator

Screen Types

There are five different style screens in regard to how they deal with the light that hits the screen from the projector. Diffusion screens, reflective screens, retroreflective screens, rear projection screens, and curved screens.

Diffusion Screens

With a diffusion style screen when the light hits the screen it scatters in all directions evenly. This promotes a very wide viewing angle with no hot spotting and zero color shift. But they also tend to be the dimmest of the three because the light that hits the screen is scattered evenly and not directed back towards your eyes. Most diffusion style screens will have a gain of around 1. You should use a diffusion style screen when you need a large viewing angle so that the image is equally bright and there is no color shift for all the seats in the theater. Diffusion style screens are most applicable when you have a bright projector and you have perfect light control.

Reflective Screens

Reflective screens contain a special top layer which increases the reflective properties of the screen. This style of screen is suitable for rooms with some ambient light or for projectors with lower light output. These screens reflect light in the opposite direction of the projector and therefore should be used with ceiling mounted projectors. This is probably the most common style screen, pretty much any screen that has a gain above 1 could be considered a reflective screen. Reflective screens have a slightly smaller viewing angle than diffusion style screens.

Retroreflective Screens

Retroreflective screens reflect the light primarily in the direction of the projector which makes them perfect for floor or table mounted projectors. Retroreflective screens are also very good at dealing with ambient light. Retroreflective screens tend to have a high gain value (2+); they do tend to suffer from a narrow viewing angle and color shifting though. Some may exhibit hot spotting as well. Retroreflective screens generally have a smaller viewing angle than reflective screens.

Rear Projection Screens

Rear projection screens are used when you mount the projector behind the screen. Rear projection screens have several advantages; they are excellent at handling ambient light, they tend to be quite bright, the projector is hidden out of view, and since the projector is behind the screen there is no noise from the projector.

Curved Screens

The purpose of a curved screen is to direct all the light that is projected to the screen back to the viewer. With a flat screen you will get light that bounces off the screen and bounces around the room. With a curved screen the vast majority of the light is bounced back to the source which results in a very bright image. Curved screens tend to have a very high gain value, i.e. a gain of 13 is common. A curved screen can get away with such a high gain because it essentially turns the entire screen into a giant hot spot so there is no visible hot spot. Curved screens are extremely bright and work very well in situations with ambient light. They can exhibit color shifting though.

Screen Terms

There is a lot of strange lingo that you come across when looking at screens; here is a list of the most common terms and what they mean.

Viewing Angle

The viewing angle (also known as the viewing cone) is the angle from the perpendicular from which the screen is best viewed. People within the viewing angle will enjoy the best picture quality while viewers outside of the viewing angle will experience a change in brightness, and possibly color shifting.

Screen Gain

Gain is a measure of brightness as compared to a block of magnesium carbonate, which is the industry’s standard for gain of 1.0. The higher the gain number the more reflective the screen, hence the brighter the image appears to the viewers. One thing to keep in mind is that a screen cannot add brightness to your projector; the only way a screen can show a perceived brightness advantage is to focus the light it reflects back to the viewers. This light has to come from somewhere and it comes from the viewing angle. The higher the gain of a screen the brighter it will be when you are directly within the viewing angle and the dimmer it will become the farther you get from the viewing angle.

Below is an exagerated example of how screen gain will effect the picture when you move from right to left from the ideal viewing angle.

Color Shift

Color shift is only a problem for CRT projectors; any of you digital guys out there reading this won’t have to worry about it. Since CRT projectors have three light sources and only one of them is in the middle (Green) the Red and the Blue are off to the sides. When you move to the left of the viewing cone the image will turn redder and if you move to the right the image turns blue. Screens with a low gain tend to not have this problem, while screens with a high gain will exhibit color shifting.

Below is an exagerated example of color shifting and how it effects the picture when you move from right to left from the ideal viewing angle.

Hot Spotting

Hot spotting is when the center of the image will be brighter than the edges. Again this is not a problem with low gain screens but can become a problem for screens with a higher gain. Hot spotting is caused by insufficient light diffusion. The image below demonstrates the effect; notice how the image dims towards the edges and corners.

Foot Lamberts

Foot lamberts relates to how bright the screen actually is. The ideal measurement is 11 fL with 10-11 fL good. For reference a direct view TV measures between 25-35 fL. You can get a good idea of the foot lamberts of a projector/screen combo using some simple math. Take the number of ANSI Lumens of your projector and divide it by the screen size in square feet (area), then multiply that by the screen’s gain. For example a projector with an output of 400 ANSI lumens matched with a 100″ screen (60″ by 80″ which is 33.34 square feet) with a gain of 1.3 will produce an image with a brightness of 15.6 fL.

Here is the calculation for you:

ANSI Lumens of projector
———————— X screen gain = foot lamberts
Square footage of screen

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This guide was written by Rachael Bellomy who was nice enough to allow me to post it here on my site. She has a pretty wacky web site check it out here.

If you’re reading this I’m assuming that you don’t know much or enough about the Laserdisc format. Here, I’ll fill you in with a history of the format, advice about players, advice about discs, general terms, and how to hook up players.

HISTORY OF THE LASERDISC FORMAT

The format first appeared in Atlanta and a few other test markets in 1978. At that point it was being pushed by Phillips / Magnavox and MCA. The discs were marketed under the name DiscoVision. The early Magnavox players were called MagnaVision. The players were all single-side, top-loaders. The video output was an RF (radio frequency) cable to go to a TV’s antenna input and also carried a mono audio track. Until about 1990 most players gave you the option of using RF output or composite video output. Most of the early players also featured a pair of jacks to export high quality analog stereo sound to an amplifier or home stereo system.

The early DiscoVision discs were generally defective. They were all CAV (discs that only fit 30 minutes per side, more info about CAV is explained below). They all suffered from manufacturing defects. If they were playable they had some degree of spots in the picture caused by air inside the disc. Air inside a Laserdisc will cause it to rot (rot means the oxygen in the air breaks down the aluminum substrate that contains the pits that contain the program information that the players read.) The picture gets more and more spots that appear over time and the audio gets pops and other abnormalities.

Eventually, they figured out how to vacuum out the air during the disc manufacturing process, but it took a few more years to figure out that the glue they were using to seal the two plastic halves that covered the aluminum substrate was gradually oxidizing and releasing oxygen into the discs. It’s a good rule of thumb to avoid Laserdiscs dated 1984 and older unless you can demo it and see that it’s still playable. By 1982 most discs were CLV, up to 1 hour per side, more about CLV later.

In 1981, after DiscoVision was stalled, Pioneer became involved in making players and discs and the format began to move towards it’s modern incarnation. A few years later composite video outputs appeared and in 1986 Pioneer’s first statement player, the LD-S1 even featured S-Video output and an optical digital output to send the digital audio stream of the new Digital Sound (PCM) discs to an outboard digital to analog converter. A few years later, the first LD/CD combo-players appeared.

By 1988 Pioneer’s entire line, except the statement player LD-S2 and the LD-W1 (auto-flip, double disc player that played four sides in succession), was made up of CD/LD combo-players. Also, in 1988 I found out about discs that had OAR (original aspect ratio) and started buying them. If there were OAR discs before that, they were few and I didn’t know about them. Anyway, the gradual shift to mostly proper OAR discs began.

Players stayed pretty much the same, with only small improvements like a small drawer for CD’s, until 1994 when Pioneer released the HLD-X0 in Japan. It was the first player to feature an AC-3 (Audio Coder #3, the original name for Dolby Digital) output. In 1995 Pioneer’s entire U.S. lineup, except the budget model CLD-S104, featured an special AC-3 RF output, allowing people with proper decoders to experience multiple channel surround sound at home! More about AC-3 RF later.

In 1997 Pioneer introduced their ultimate combo-players that handled LD’s, CD’s, and DVD’s. Pioneer is no longer manufacturing LD players for the U.S. A few dealers still have DVL-919 or the ELite DVL-91 (DVD/LD combination players) in stock.

In Japan where the LD format was far more popular, Pioneer is making the last production runs of LD players now (spring 2002). Pioneer has announced that 1 June 2002 is the official end of the Laserdisc format. They’ll provide service for many years to come, undoubtedly. Other manufacturers quit offering LD players in the U.S. between 1994 and 1996. That pretty much brings us up to the present and it’s time to move on to the technical specs of the format.

LASERDISC TERMS

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CAV = Constant Angular Velocity is also called “Standard Play”. CAV discs or sides are limited to 30 minutes a side. The frames of CAV discs correspond to the actual film frames. So, when you pause, or still frame, on a disc the image you is one of the film’s frames. CAV is often used on disc sides that contain extra or special materials. It’s perfect for displaying images of things like movie posters or pictures of the set or cast. CAV discs/sides have a running frame count instead of running time in the player’s display. CAV discs/sides allow the user to use all the format’s playback features which include: frame by frame advance, still frame, and multi-speed. CAV discs are a great way to study how films are put together. Many people don’t like them for casual viewing since the disc must be changed more often. Many CLV disc sets have one side, typically the last side, in the CAV format. CAV picture quality is said to exceed CLV picture quality by 1 to 2%, but it’s never been readily apparent to me.

CLV = Constant Linear Velocity discs, sometimes called “Extended Play” can typically hold up to one hour per side, a very few have exceeded that. But, most LD users will never see that (It’s rare for US discs to exceed 60 minutes, but a little more common on Japanese LD’s)

The overwhelming majority of discs are CLV. Using basic LD players, CLV disc’s don’t allow the use of the player’s still frame or frame advance. You cannot view the film’s actual frames on CLV discs. They are not available. Some nicer player have Digital Field Memory (DFM). Using DFM one can use still frame and frame advance to see still images but they are not the film’s actual frames. Since about 1990 nearly all higher-end players have featured DFM.

DIGITAL SOUND When an LD is thusly labeled it means it has a PCM digital audio track which could be mono, stereo, or Pro-Logic. In the laserdisc world, “Digital Sound” does not mean 5.1 Dolby Digital or DTS.

CX NOISE REDUCTION CX noise reduction was used on analog Laserdiscs or the alternative analog soundtrack that is present on Digital Sound Laserdiscs. I think it’s something along the lines of various Dolby noise reduction systems (A, B, C, ect.). I think it simply raises the signal above the noise floor like Dolby does. The sound on analog sound laserdiscs is generally pretty good.

TRICK PLAY Is a term that generally refers to Digital Field Memory (see above in CLV) or other special playback functions. Some nicer players, like the CLD-99, have STROBE playback. It drops some of the frames but maintains the sound. The image will look like a series of stills. Many camcorders have similar functions. The Panasonic LX-1000U even has an odd paint function that will give the image a chalky, animated look.

AC-3, THE LONG FORM….

AC-3 = AUDIO CODER #3, it’s the original name for Dolby Digital on Laserdics.

The last count I heard was that there were over 800 AC-3 Laserdiscs released in the U.S. I think CLEAR AND PRESENT DANGER was the first. The first one I got was STARGATE.

AC-3 has caused beaucoups of confusion with more than a few LD newbies. Here, I’ll explain it. The original LD format specifications included a stereo analog soundtrack plus analog left and analog right options. In the mid ’80’s the digital audio channel was added to the LD specifications. After Digital Sound appeared Pioneer insisted that all Laserdiscs maintain an analog soundtrack to maintain compatibility with older players that only supported analog sound.

Now, in 1994 when Pioneer added AC-3 surround sound to the Laserdisc specifications they wanted to maintain compatibility with as many of the older players as possible. The only players that would not be able to play the AC-3 encoded discs would be the very early players that only had an RF output for video and analog sound, that was routed into a TV’s antenna input. The analog right channel was the channel that was routed into the player’s RF output.

Pioneer decided there were not that many people still using players with only RF output. They obviously wanted to maintain the digital PCM tracks and wanted to maintain the analog left channel for commentary or an alternative language. So they came up with a system to transform the digital AC-3 signal into an analog signal (like a computer modem does to transmit digital info over an analog phone line) and they placed the AC-3 sound in the analog right channel. A new dedicated AC-3 RF output had to be added to players.

You cannot plug a AC-3 RF digital output straight into an ordinary modern Dolby Digital input on a receiver or preamp. The AC-3 signal must be extracted (called demodulated) from the analog carrier. Some older or higher-end receivers have an input with an RF demodulator built-in to perform this function. If a receiver does not have this special RF input, you can obtain an outboard RF demodulator to perform the function.

You send the AC-3 RF line into the little box and it turns that analog signal back into a digital stream. That output creates a Dolby Digital bitstream that is compatible with regular modern digital inputs. The good part of all this is that Pioneer maintained a lot of backward compatibility. The down side is they created the situation of having to “fish” the AC-3 signal out of the RF analog carrier.

AC-3 RF MOD If your player doesn’t have an output jack for AC-3, don’t worry. Most older LD players can be modified and given an AC-3 output with a simple kit you can still find online.

DTS = DIGITAL THEATER SYSTEM DTS for home theater was used on a limited number of discs between 1996 and 1999. JURASSIC PARK was the first DTS LD. On DTS LD’s, DTS replaces the PCM digital track. DTS LD’s also have an alternative analog soundtrack so they can be played on any player. You must have a player with an optical or coaxial digital output (this will be a different output from the AC-3 RF output) to export the DTS bitstream to a DTS decoder to enjoy the DTS track.

AUTO-FLIP or AUTO-REVERSE refers to players that can automatically play both sides of a disc. The laser that reads the disc starts out on the bottom reading side 1 and tracks the disc from the inside to the outside edge. Then, when side one is done, there is a pause of about 10 to 20 seconds, while the laser reader rides a rail to the inside edge of the top of the disc so it can begin reading side two. After side two is done, the laser automatically resets to the bottom and is ready to read a side one again. Single-side players require you to flip the disc over after each side by hand.

LASER ROT I’ve mentioned this already but I’ll give it a more complete description here. Mostly, laser rot is caused by bad manufacturing.

If air is left inside the disc when it’s manufactured the oxygen will break down the disc within two years, and a multitude of “snowy” spots will appear in the image and the sound will develop defects. If the glue seal around the disc’s edge is never good or gets broken by rough handling, air gets in and rot begins. I think the laser rot problem has been greatly over stated. I have about 800 LD’s and I have about 10 post 1985 discs that are rotted.

The majority of rotted discs from the 1990’s came from the Sony manufacturing plant in Indiana. Be weary of Columbia and Sony Music Video discs that came from that plant. I still buy LD’s of material that’s not available on DVD.

Personally, I prefer to buy used, open discs because the original owner would of returned the disc if it was defective. I’ve bought over 100 LD’s on eBay-bay and have only once had somebody send me a rotted disc.

MUSE or HI-VISION LASERDISC The names are interchangeable. Hi-Vision is the analog 1035i, hi-def, 16 x 9 television system in Japan. The Muse LD format was invented by Sony and ran from 1992 to 1997 It’s resolution is about 650i. Muse LD reproduction requires a Muse capable player like the HLD-X9 or HLD-X0 (imported laserdisc players from Japan), a Muse set-top box, and a 16 x 9 hi-def set or projector. The format never really got perfected. The early discs from 1992 and 1993 generally have problems maintaining proper colour balance and suffer from some nasty motion artifacts in spots. Digital video tape-based material worked wonderfully with the format from the start. Film-based material gradually improved. Some of the films look better than DVD, most do not though.

LD GRAPHICS or LD-G LD Graphics are subtitle tracks available on selected Japanese Laserdiscs. It works on the same principle as closed-caption does in the LD format. Theoretically LD-G Laserdiscs could have more than a dozen different subtitle tracks. Three is the most I’ve seen on a disc. You should be able to remove all subtitles from the screen using LD-G, but most imported discs have the Japanese subtitles “burned-in” so to speak (the subtitles are part of the video signal and cannot be removed). The STAR WARS PHANTOM MENACE LD is a perfect example and the only Japanese LD a great many folks have ever seen. If you have an LD-G capable player, you can super-impose English sub-titles on top of the Japanese ones. Occasionally you can see the edges of the Japanese ones. A few MULTI AUDIO Japanese LD’s feature LD-G subtitle tracks that are removable from the screen. The only U.S. player that ever had the LD-G feature was the Denon MD-3500.

LASERDISC PLAYERS

CLD-D503 Laserdisc/Cd combo and movies US $350.00 End Date: Tuesday Mar-16-2010 16:22:23 PDT Add to watch list

PIONEER ELITE CLD-99 LASER DISC PLAYER EXCELLENT COND! US $355.00 (14 Bids) End Date: Thursday Mar-18-2010 20:30:57 PDT Add to watch list

McIntosh MLD7020 Laser Disc Player US $349.99 (1 Bid) End Date: Friday Mar-19-2010 8:32:30 PDT Add to watch list

PIONEER DVL-V888 CD DVD LD LASER DISC PLAYER W/ REMOTE US $569.99 End Date: Friday Mar-19-2010 9:15:04 PDT Add to watch list

Pioneer DVL-700 Player - Laserdisc US $200.00 (0 Bid) End Date: Sunday Mar-21-2010 12:56:42 PDT Add to watch list

Laserdisc is a very old format as we learned in the history section. It is a composite video format, where as DVD is a component video format. Many Laserdisc players come with S-video output, but for most of these players their composite video outputs are better.

With a composite format, the chroma (colour, free of white and gray) portion and luminesce (black or light level, from this point on luma) are together in one cable and must be separated at some point for the NTSC TV to use them. (I’m not the most technically astute person. That’s the best way I can describe it.) Anyway, with a four pin S-Video signal, the chroma and luma elements each occupy two of the pins. How did this happen? A comb filter separated them.

The point is, in order to be displayed by the TV- the composite format must be converted to a component format. That can either happen in the LD player (if you use the S-video connection, a filter inside the player will convert the signal and pass it on the S-video connection)– or that can happen at the TV set (using the composite cable will mean the LD player will send composite video, which the TV separates using its filter).

So, getting the best picture is a question of which filter is better in your system- the TV’s or the LD’s. If you have a cheaper player, chances are the picture will be better using the TV comb filter- so if you connect via composite output on the player- this will use the TV’s filter, and will usually result in a better picture.

All NTSC televisions have some sort of comb filter to separate composite video coming into their composite inputs. They vary in quality greatly. Most newer sets now have two or three line digital comb filters, three being better, usually. Nice sets have some variation of a 3-D comb filter.

Only the top Laserdisc players that have really good S-Video output with 3-D comb filters on board. The Pioneer CLD-97 has a 2-D comb filter that is close to as good as a 3d filter. It’s filter was hot technology back in 1993-4. Can you remember back that far? That’s a long time ago in the A/V world.

What players have great or at least excellent comb filters on board? Furthermore, why is that advantageous? I think the advantages are generally two-fold. First, the comb filter is optimized for the player. Secondly, most of the players that feature 3-D filters let you adjust them to optimize their output for your display. The 3-D comb filter in the Elite CLD-99 is adjustable. You can even adjust it to operate in 2-D if you want.

THE GREAT LD PLAYERS

What are the great LD players? Here I’m going to have to mention the Japanese market. LD was/is vastly more popular there. In the latter days of the LD era, they quit sending their very best players here. Several of the best players are Japanese players that can be imported if you want the very best LD performance.

For this list, I’m going to start with the absolute best first, and work my way down.

I’ve never seen one in person, but I’m told that the Japanese HLD-X0 is the world’s best player. It’s certainly the heaviest at 35 kg. (79 lb). It cost about $8000 new in 1994. It’s a single-side, all-out performance player.

The ‘H’ in it’s model # indicates that is a Muse capable player. It’s a dedicated LD player, in other words, it is optimized for and only plays 8 and 12 inch Muse and NTSC LD’s- not CD’s. It was the first player to come equipped with an AC-3 output. There are not too many of them in the U.S. I do know of one person who has one. The HLD-X0 is a non factor for most of us. I wouldn’t mind having one but I’m not sure I could lift it! (Note: You have to have one imported from Japan, as it was never released in the USA.)

The best auto-flip, relatively affordable player (well, yeah it’s expensive, $2500– But, it’s worth it if you can’t live without hi-end LD playback) to get is the Pioneer HLD-X9, another Hi-Vision, AC-3 capable player from Japan.

It features a red laser that gives a better read of discs, nearly speckle-free. The red laser will also make the best of scuffed or rotted discs. It will make most rotted discs playable, not perfect, but playable. It kicks butt with good, clean discs! The only limitation is how well-mastered the disc is. It has the best 3-D comb filter ever put in a Laserdisc player so it thusly has superior S-Video output.

It’s colour reproduction rivals that of DVD, software permitting, of course. It’s remote has a switch, labeled D-EXT that let’s you tog back and forth the correct NTSC colour temperature for Japanese NTSC and the U.S. standard. So, both U.S. and Japanese LD’s will look their best. The X9 is the top of the LD universe. (Note: You have to have one imported from Japan, as it was never released in the USA.)

The X9’s little brother is the LD-S9, a dedicated NTSC LD player. It has the same NTSC circuitry, including the same hotshot 3-D comb filter, as the X9. It uses a conventional laser head however. The S9’s video performance is very nearly as good as the X9, it’s very close. However, you lose the X9’s ability to read damaged discs, but the S9 really excels on good, clean discs. It also features the LD-G feature, AC-3 output, the works, of course! It’s as good an LD player as most people could ever need. (Note: You have to have one imported from Japan, as it was never released in the USA.)

I have not seen the Runco players except in pictures. They’re rather rare. Both models, the LD-RJI and LD-RJII, are pretty much the same except the JRII came stock with an AC-3 output. I’m not sure what kind of laser head the Runco players feature, but the one person I know of who owns one told me it would read rotted discs. It’s the only Laserdisc player that was ever THX approved. It may be the only one that ever applied? I’m sure the hi-end Japanese players could easily pass too. Anyway, it’s said to be an awfully good player and close to as good as the HLD-X9. The Runco players sold for $4000+ new.

The Pioneer Elite CLD-99 is a pretty darn good player. It cuts video noise really well providing a far clearer image than average LD players. It has Pioneer’s second best 3-D comb filter. It’s colour performance isn’t as good as the X9 or S9, but it’s no slouch. The CLD-99 has all the sound output options including, of course, AC-3. On eBay-bay you may occasionally see the CLD-D99 which is the same player as the Elite 99 except, it’s silver, no wood side panels, it has heavy metal side panels that make it weigh about 5 lb’s more. It was made for export to Asia and Pacifica. It will work just fine on U.S. sets.

The Elite CLD-97 was Pioneer’s best U.S. model in 1993 and 1994. It feature an excellent 2-D comb filter. Some people prefer it’s S-Video output to the CLD-99’s, I don’t. The CLD-97’s composite output is better than the CLD-99’s. So, if you have a display or video processor with a great comb filter, the 97 could be a great player for you. It predates AC-3 though but can be modified for AC-3 output. A great many of the CLD-97’s I’ve seen on the used market have been modified. Be sure and ask if you’re looking at one. Theta and Macintosh both offered clones of the CLD-97.

The Great Players are all going to deliver 52 db to 54+ db video S/N performance. They’ll make LD much more involving than lesser players.

ABOVE AVERAGE LASERDISC PLAYERS

This group of players offer above average performance but aren’t quite as good as the great players. Most offer S-Video output but it may not really be useful unless your display has a really ho-hum comb filter circuit. Remember, Laserdisc is a composite format and the only reason to use S-Video output, if provided, is because the player’s comb filter is better than the display’s. That’s becoming increasingly unlikely with today’s TV sets.

The Panasonic LX-900 and it’s clone the Denon MD-3500 are almost good enough to make the great players list but not quite. They both offer a really heavy build quality, over 10 kg (22.6 lb). They feature 3-line comb filters that may be useful depending upon your display. These models really cut video noise very, very well, better than Pioneer’s U.S. models except for the 99 and 97 and 95. They predate AC-3 but both offer optical digital output. These are very desirable players if you can find samples that aren’t too worn out by now. They were current models in about 1992 through 1994.

The Elite CLD-79 is very much like the CLD-99 except you get a 3-line comb filter instead of a 3-D comb filter. It can’t cut video noise quite as well as the 99 but it’s colour performance is just as good. It’s S-Video output can be useful with some TV’s. It has all the sound outputs including AC-3.

The Pioneer CLD-D704 is very similar to the CLD-79 despite a very different face-plate. It’s the best non-Elite player they ever made. It’s build quality isn’t as heavy as the 79’s and it’s analog audio section isn’t quite as good but it’s pic quality is right there with the 79’s. The CLD-D703 is the same as the 704 except it’s a year older and lacks an AC-3 output. The CLD-D702 is still a year older and it’s 3-line comb filter isn’t quite as good. It’s composite output is very above average. The still older CLD-D701 is a cut below the 702 and is much less desirable. It also has a reputation for breakdowns. I’d recommend avoiding it. Did I say it’s pretty old now too? Mitsu has a clone of the CLD-D704, by the way.

In many ways the LD-S2 is the best player in this group. I picked one up a few inches at a friend’s repair shop once. It weighs 67 lb’s, nearly 30 kg! You could hurt your back. I think later editions of it weighed even a bit more, 70 lb’s. The LD-S2 was made from about 1988 till 1997. You had to order them, mostly. Oh, did I mention they sold for about $3000? The S2 is the most over-built model ever offered to the U.S. market, only the 79 lb HLD-X0 is beefier in the history of the world. The S2’s transport is very quiet. It has a laser head that will read rotted discs. It has superb analog audio output, but the pic quality is a bit shy of the great players. It’s an old design. Oh, I forgot to mention it’s a single-side player but one that it’s worth the trouble of turning discs over for.

The Elite CLD-95 has got the CLD-97’s bulk at 38 pounds, but it’s a few features short of it’s successor. It’s S-Video output isn’t impressive. In 1991 comb filter technology had a way to go. On the other hand, the 95’s composite output is superb. The 95’s video performance is only limited by how good a comb filter you feed it into. When feeding it’s composite into an outboard comb filter like a Crystal Visions or into a TV with a quality 3-D comb filter, the 95 can perform up to the low end of the great players. It predates AC-3 but is easily mod’ed.

The Elite DVL’s 90 and 91 perform about the same as CLD’s 704/79 do for LD. The 91 is better for DVD’s because it will pass DTS sound for them. The 91’s ergonomics for DVD and remote are better too. But, when it comes down to LD performance, the two are about the same.

THE Panasonic LX-1000U, which is also called “Prism”, is an old but above average player. It’s an early 90’s player. It’s S-Video output isn’t great by today’s standards, but it’s composite is really good and looks really crisp when fed into a TV with a 3-D comb filter. It has the full compliment of trick play too, digital field memory, strobe effect, and even a three level paint function. It’s a cool player.

The Above Average players are going to deliver video performance of 51 db video S/N or maybe just a bit better. Their pic’s will have noticeably less video noise.

LD-W1 gets on this list despite very average pic quality. The LD-W1 is a double drawer player with auto-flip, capable of playing 4 disc sides in succession. That’s a cool trick and it’s the only such U.S. model as far as I know. No digital output or AC-3 output. This a late 80’s player, but it was a cool idea!

AVERAGE LASERDISC PLAYERS

I’m going to start this section by telling you that the average performance players, visually, of Pioneer players took a jump for the better in 1995. Since 1995 about the only models that won’t deliver a 50 db video S/N performance are the CLD’s S104, S304, and D406. The good news is that even those three players do 49 db. In the late 80’s and early 90’s most players performed at about 47 or 48 db. That translates down to a considerably noisier picture. Since 1995 every Pioneer LD player except the CLD-S104 has an AC-3 output. Post ‘95 are the players to shop for, generally. Some of these players are the DVL models that also play DVD’s.

PIONEER’S 1995 lineup

CLD-S104 Visually, it’s the best single-side budget player ever. Composite video only, and left and right analog sound outputs only. It’s picture will beat all the older budget players. It looks and sounds better than a S-VHS VCR hands down. Originally sold for $300 in 1995. I’ve seen them sell for $30 and less on eBay-bay. If you just want a simple-stupid, inexpensive player the S-104 can be a good choice.

CLD-S304 Same performance and features as the 104 but adds an AC-3 output and sing along Karaoke -dfgwrt” input features.

CLD-D504 This player has auto flip, AC-3, but no PCM digital output if you need that too. It was their budget auto-flip model of the year.

CLD-D604 adds optical output and has the always fun (?) “karry-okee” function. Average video quality, AC-3, of course…

CLD-D704 one of the Above Average players.

Elite CLD-59 has the average pic quality but great sound. AC-3 of course! Coaxial digital audio output. Yamaha 901 and Marantz 520 are known clones.

Elite CLD-79 Above Average of course, see above!

Elite CLD-99 see great players above…

Since ‘96, there’s the CLD-D606, CLD-D406, CLD-D505, CLD-D605, DVL-700, DVL-909, DVL-919. All these players have about the same pic quality except the 406’s is a tad less. The older CLD’s D502 and D503 hold interest for some folks, they have auto-flip and optical outputs. They were current models in 1993 and 1994, respectively.

Older players should be avoided unless you’re getting one of the players on the Above Average or Great lists or a hell of good price! Older Elite models like the CLD’s 52 or 53 offer very average pic quality but do offer toslink and coaxial digital audio outputs. RCA, Pro-Scan, Yamaha, Mitsu, Marantz, Kenwood, Denon, and others sold clones of Pioneer’s average players, mostly. Mitsu had a clone of the above average CLD-D704. Theta and Macintosh cloned the 97, but most clones are very average players. Some older players have digital outputs others don’t, you’d best check if you need that feature.

Outside of Pioneer made players I like Panasonic players. The LX-600 is good average player. The only problem with them is that Panasonic isn’t as dedicated to service of older players as Pioneer is. I would avoid Sony, Realistic, and Phillips/Magnavox players in general. Only if they’re dirt cheap are they worth fooling with. Sony has a few nicer players but their service-support isn’t good. Most of their models are prone to drawer problems. Sony USA released no great players. Reportedly, Sony Japan has…! Sony players are generally harder to mod for AC-3 output than Pioneer models, if that’s a consideration.

SOME PIONEER PLAYERS TO AVOID

CLD’s S980, S990, S1080 < These players can't always have their lasers realigned if it gets out of sorts, bad cheap design. The CLD-M401 has a 5-CD changer built in but is prone to way too many breakdowns according to a technican friend. I'd avoid all 1980's models unless you just want a $30, or less, toy. The older players just can't match up on pic quality or newness!

HOOKING UP LASERDISC PLAYERS

Always hook the players analog L & R audio outputs up. That’s all some players have anyway. Even if you’re hooking up a player with a digital output, you need the analog out’s hooked up too. Why? Because some older discs from the 80’s have only analog sound, because there could an alternate language, commentary track, or both. Many Japanese Laserdiscs have English on the digital channel and Japanese on the analog channel. Anyway, always hook-up analog audio.

If your player has either an optical or coaxial digital output, or both, yea, choose a line of transmission. You’ll be feeding your pre/receiver PCM, same as a CD, unless it’s it’s a DTS LD where the PCM track has been replaced by quess what? DTS, of course.
If your player has an AC-3 output, hook it up with a very shielded cable. There’s an RF (radio frequency) signal in this cable till it hit’s a demodulator, either in a receiver or an outboard demodulator box. Bad shielding could cause interference with other components? After demodulation the AC-3 stream is just like a DVD’s Dolby Digital signal, just at a slightly lower bit-rate.

There are prehistoric LD players from the 80’s that only have RF video out. I hope you’ll not be hooking up that way…! Many LD players only have composite video output. Composite is the hook-up of choice for LD players, unless you’ve got one of the Great Players or maybe one of the Above Average players? Many players have S-Video outputs which should not be used. Since this is the DVD age where S-Video is good, composite is bad days, it’s the other way around with Laserdisc. Only the great players have great S-Video output because of the terrific comb filters they have on board. Well, some of the above average players will have S-Video output that’s useful with some TV’s. Try both if you have them. The 3-line and most especially the 3-D comb filters in today’s TV’s will like the taste of LD composite video.

If you have a digital TV or projector, you may want to deinterlace your LD player with an outboard video processor like the DVDO iscan V1, V2, or Pro. I’ve had the LD-S9 hooked up with S-Video into quite a few brands of monitors from Sharp, JVC Priemer, Loewe, Sony, and Pioneer Elite. Suprise, suprise, in my experience the line-doubler in Elite 510/610/710 16 x 9 sets does LD better than the rest. iscan’d video will look better on most HDTV monitors. The iscan units have RGB outputs, but you can get a cable that converts RGB to 3 line component output. The point I’m making is that the internal line-doublers on most HDTV monitors won’t always do LD playback any justice, even if you have one of the great players.

EPILOG.

CLD-D503 Laserdisc/Cd combo and movies US $350.00 End Date: Tuesday Mar-16-2010 16:22:23 PDT Add to watch list

Pioneer Laser Disc Player + 5 classic movies US $49.00 (1 Bid) End Date: Tuesday Mar-16-2010 17:06:42 PDT Add to watch list

Pioneer Model CLD-V2800 CD CDV LaserDisc Player US $54.99 End Date: Tuesday Mar-16-2010 18:01:57 PDT Add to watch list

Excellent Condition Yamaha CDV-W901 Laserdisc Player US $150.00 (7 Bids) End Date: Tuesday Mar-16-2010 18:54:03 PDT Add to watch list

SONY MDP-210/322GX LASERDISC PLAYER SERVICE MANUAL-RARE US $9.99 End Date: Tuesday Mar-16-2010 19:43:59 PDT Add to watch list

Remember, in terms of video quality, LD players vary way more than DVD players do. Only the great players will aproach DVD performance. Most of the best players have been made since 1995. Composite video output is usually best. If there’s no sound and all you have is a digital audio connection, you’re proably playing an analog sound disc. AC-3 audio requires demodulation, and you’re just about ready to spin Laserdiscs.

There’s 17,000+ U.S. LD releases and 30,000+ Japanese releases to choose from, or look for since the format is out of print. Many cult films, classic movies from the 20’s thru the 70’s, and many music LD’s don’t seem destined for DVD release anytime soon if ever?

Intresting discs are out there, somwhere. From STAR WARS to SONG OF THE SOUTH to ROBINSON CRUSOE ON MARS to WINGS OF DESIRE to DR. JOHN’S NEW ORLEANS SWAMP to SINK THE BISMARCK and all the really cool boxsets, there’s a lot of intresting content to collect out there that’s not on DVD. Good hunting!

Looking to buy a Laser disc player? Then check out my Laserdisc store!

Hello to all G70 owners !

Since I’ve been asked for information on silencing the Sony G70 projector and because I made it again for my brother’s G70 unit, I’ve decided to post this step by step procedure. This mod will cut the noise by approximately 8 dBA (nearly half the noise level).

The G70 unit hold three 120×120x38mm Japan Servo CNDC12B4 (40dBA noise each !) that draw ~85CFM each. Then, I would assume that changing these fans to SilenX IXP-76-14 (72 CFM) is the best replacement part versus the original 85CFM. Note that there is also the 90CFM version (IXP-76-18) from SilenX that could be use for this fans replacement but the noise is rized from 14dBA to 18dBA each.

Here is the complete SilenX IXP-76-14 specifications

http://www.silenx.com/ixtremaprofans.asp?sku=ixp-76-14
SKU: IXP-76-14
Rated dBA: 14 dbA
Dimensions:120×120x38mm
RPM: 1200 rpm
airflow: 72 CFM
nominal Voltage: 12V
Current Draw: 0,20A
Power Consumption: 2.40W
Bearings: Hybrid Immersion

Step 1 Remove the G70 front and rear top ABS covers. Unscrew the center aluminium cover screw and open it toward the front. Remove the fans wiring assembly from the fans plastic housing tabs :

Finally unscrew the first fan plastic holder (two black top screws), disconnect the fan connector and remove the fan assembly out of the unit.

Step 2 Disassemble the original Sony fan from its housing by removing its four rubber spacers relief from the fan housing :

Then remove the four SilenX rubber spacers from the fan itself :

Step 3 Order one Samtec PCB header from RS-components/Radiospares (order code 277 9742 – see the Samtec relevant DS page in here). Update it to retreive three 3 pins headers like this :

Step 4 Place the four rubber spacers inside the SilenX new fan :

Step 5 Before placing the new fan inside the sony plastic housing, place the fan’s wires like this:

Step 6 Place the new SilenX fan with its four rubber spacers inside the Sony plastic housing :

Take car that the fan’s connector must been outputed on the right side !

Step 7 At this stage, update the SilenX white connector housing wiring to fit Sony wiring by swapping the +12V and SENSE wires:

Step 8 Place the three pins header inside the SilenX connector housing:

Step 9 Place the fan assembly back inside the G70 unit and Connect it to the Sony internal connector this way (you must check that wires colors vs SilenX connector housing is OK):

Step 10 Wrap 7cm of electrician scotch tape all around the connectors assembly:

Step 11 Place the fan+housing assembly back in place (check that lower tabs fit their slots) and place back the two black screws to secure it :

Step 12 Update the rest of the fans (2) exactly like the first one:

All noise measurements were made before and after the fan replacement at a 1m distance from the back of the G70 with it’s outer plastic shell removed (ie: worst case scenario).

Here is the results :

- Noise floor : 34dBA
- With original Sony fans: 47.4dBA
- With new SilenX fans: 39.4dBA

Overall noise Gain : 8dBA not that bad

That’s it! The fans should all run fine when the unit is powered up. The big difference being how G70 is now even quieter than before. Enjoy!

John