CED VideoDisc and Player Discussion

[cwvsced]

I'm new to CED for the most part. Have an RCA SGT-200 that has a good picture, but as some point during the movies the picture "waves" slightly. The picture never goes away and it is not unwatchable...it's just annoying. There are no lines or noise in the picture, just some instability that lasts a few seconds then goes away and comes back later. It always happens in the same place on the movie. I seem to notice it more on "real people" movies as opposed to animated features. Could it be the drive belt or is it something else?

[RT9342]

When you say the picture "waves", do the colors change any? The only waviness that I've ever noticed on the SFT & SGT models causes the picture to shimmer a little, but it also throws off the hue.

Does it happen about every 6 or 7 seconds, lasting about a second or 2?

If so, I've seen that problem in one of my players, and so have other owners of SFT & SGT models. But to be honest, I haven't ever come up with a cure to the problem, as I salvaged my temperamental player for parts. However, I have recently learned more about how the motor works, and I'm suspecting that the problem is either in the belt or the motor itself.

The motor is a hybrid motor - it's a shaded pole inductor motor, which would normally run about 3450 RPM, but it also has a magnet to synchronize it to the 60Hz line current, thus causing the motor to rotate at exactly 3600 RPM. Ideally, this would drive the turntable at exactly 450 RPM, but in reality, the turntable speed would not remain constant. So, RCA put a 16-pole magnet around the underside of the turntable, as well as 2 poles sticking up off the motor, which synchronize the turntable itself as the motor applies the majority of the torque via the belt.

The problem seems to be that the turntable starts getting out of sync with the motor somehow, and it tries to hold sync, but after several seconds, it loses it, and the turntable slows down until it locks into sync again...until the next time. My best guess at this time is that slack or wear in the belt causes the sync problem, so since the belt is fairly cheap, I would suggest getting a new belt as your first option.

Please let me know if the problem you're having is different than what I described, or if a replacement belt doesn't work. Keep in mind that a new belt would be best. Before salvaging my troublesome player, I replaced the belt with a used one from player that didn't have the problem, but I saw no difference - but it's possible that both belts were worn and that one player was just more picky about the belt than the other.

[cwvsced]

The hue doesn't change. Just the picture "waves" a bit horizontally. If a line were drawn down the side of the screen, you see it "snake" a bit back and forth. It's very minor as far as anomalies go. It happens maybe 8 to 10 times during the course of a movie...lasts for about 3-5 seconds. I suspect you are right on the money about the belt. At any rate, it couldn't hurt to replace it.

Thanks for the reply.

[RT9342]

It never hurts anything to try a new belt, but I'm now wondering if that's not the cause of the problem. Usually the hue will start to get off before any noticeable waving in the picture occurs, whenever the turntable speed drops below the correct speed.

What kind of TV are you using? I use a rather unusual Samsung TV (full 1080 HD widescreen, on a 30" CRT display), and it sometimes (I'd also say about 8-10 times in a movie) gets a bit shimmery, but at the same time the brightness decreases. But my TV will also do that with older laserdiscs. Late 90's laserdiscs don't seem to have the problem, but older ones do. Most of the time it happens on the same scenes, but occasionally it won't, so apparently there's something in the mastering of older movies that my TV doesn't like.

My older TV (which is actually an old Commodore Amiga computer monitor) didn't do that - in fact, it had a really nice picture.....but it was only 14" and didn't support anything better than 30Hz standard definition. But I've heard of other people having problems with playing CEDs and laserdiscs on some TVs. I've even seen cheap 90's TVs that would produce a wavy picture on Nintendo games, depending on whether or not the graphics had a lot of bright and dark horizontal lines.

Maybe you can try your player on another TV and see what happens.

[cwvsced]

The TV is a 19" RCA. It would be a 90's model. It's probably around 12-13 years old. Interesting note about the video games having the same problem. I'll see if my children's games do the same thing. Right now, that would be easier than moving my CED player downstairs to the other TV.

Thanks!