View Full Version : Dorothy on old RCA 'CED' disc


NewVista
12-11-2012, 11:05 PM
Box says this player was for store demonstration unit.
Seems player prefers a TV with slow AFC for steady pic.
No picture in 'Pause' mode for screen photography.

Phil Nelson
12-11-2012, 11:18 PM
I restored a Wards (Toshiba) CED player a few months ago. Are you referring to horizontal jitters? My player looked wonderful on the older 27" CRT set that I have on my workshop. When I moved it upstairs and connected it to a new flat screen TV, the picture jiggled horizontally a little, making me wonder if something had gone wrong with it already.

They do make a nice picture when working right.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

NewVista
12-12-2012, 12:24 AM
Yes, depends on TV, some H stability shake, needs slower time constant ?

wa2ise
12-12-2012, 08:20 AM
RCA dropped about $570 million trying to market that thing. I used to work at the Smirnoff R&D lab where they invented it. It may be the reason GE corporate takeovered RCA, it wasn't pretty... :sigh::drool::thumbsdn::tears::yikes::para::puke: :wtf: :yuck::eek::uzi:

Eric H
12-12-2012, 08:24 AM
the Smirnoff R&D lab where they invented it.

Well that explains a lot! :D

old_tv_nut
12-12-2012, 09:19 AM
It makes me shake my head, but when you look at formats that succeeded and those that didn't, there is a correlation to whether porn was available or not. The most shocking thing on CED was "Barbarella."

Title17
12-12-2012, 09:42 AM
I swore I'd never mess with CED, then someone had a SJT-100 for sale for $5.

Had to replace some belts in the transport mechanism but it works perfect now. Pretty interesting format that pretty much everyone has long forgotten about.

Ed in Tx
12-12-2012, 11:03 AM
Wow! The discs still play! I worked on those in the early '80s when they would come into the shop still in warranty. Usually a new pickup stylus fixed the problem. Had a copy of "Mash" for my test disc. I recall the theory was the silicone lubricant on the disc would eventually dry up and make them unplayable. So much for that! Anyway, pretty cool!

Sandy G
12-12-2012, 11:10 AM
The problems w/CEDs were sort of "Soft" pictures, & the "Skipping"- Occured even when a disc was brand-new out of the wrapper. VERY aggervating to pop in a movie, sit down, & the damthing started skippin' 30 seconds into the show..

lnx64
12-12-2012, 11:11 AM
It makes me shake my head, but when you look at formats that succeeded and those that didn't, there is a correlation to whether porn was available or not. The most shocking thing on CED was "Barbarella."

I have LaserDisc and the only thing I had ran into was anime porn. Yea, not real stuff, just animated. lol

Not that I'm trying to look for either. I'm just going through the boxes of LD's when I'm at the flea market.

Ed in Tx
12-12-2012, 11:25 AM
The problems w/CEDs were sort of "Soft" pictures, & the "Skipping"- Occured even when a disc was brand-new out of the wrapper. VERY aggervating to pop in a movie, sit down, & the damthing started skippin' 30 seconds into the show..
I think the CED resolution was about par with a good VHS. Maybe 240-250 lines or so. Competing Laserdisc much higher 5-6 mHz from the video out, 400-500 lines. But they certainly had their own issues.

lnx64
12-12-2012, 11:39 AM
I don't think I understand the concept of TV lines.

For example, if VHS has around 240-250 lines, why is it still interlaced with over 400 visible lines?

Ed in Tx
12-12-2012, 11:54 AM
I don't think I understand the concept of TV lines.

For example, if VHS has around 240-250 lines, why is it still interlaced with over 400 visible lines? Relates to how many parts each horizontal line can show, making vertical lines in the picture. Equates to about 80 lines per mHz. The higher the video frequency the finer detail each horizontal line can resolve, making up vertical and overall picture detail. If that makes any sense!

lnx64
12-12-2012, 12:24 PM
Makes a little more sense. So it's basically describing how defined the horizontal line is. So for example, like 240x480 for example would be 240 lines, right?

Phil Nelson
12-12-2012, 12:26 PM
Wow! The discs still play!Indeed, they do. This article describes how I refurbished my player.

http://www.antiqueradio.org/WardsGEN10301CEDVideoPlayer.htm

There is an active CED collector community. The CED Magic (http://www.cedmagic.com/) website has extensive information about the format, specs and restoration tips for every player, a discussion forum, and so on.

I feel like CED nerds are in about the same position as TV nerds who collected 1940s TVs in the 1960s and 1970s. The players and discs are available cheap or even free at garage sales, etc., and ordinary people look at them funny for wanting to preserve this obsolete rubbish, much less use it.

I will haul my player back to the workshop and try it out on that older 1980s TV, to investigate the shakiness issue. My son was all excited to see the player working when he visited here during Thanksgiving, but disappointed when every disc looked unstable on the new flat screen.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

http://www.antiqueradio.org/art/WardsGEN10301RestoredPlaying1.jpg

http://www.antiqueradio.org/art/WardsGEN10301RestoredPlaying2.jpg

Ed in Tx
12-12-2012, 12:51 PM
Makes a little more sense. So it's basically describing how defined the horizontal line is. So for example, like 240x480 for example would be 240 lines, right? Well sort-of. If you are talking picture elements yes. How many elements each horizontal line can be divvied up. But that 240X480 could be misconstrued as aspect ratio.

Eric H
12-12-2012, 01:23 PM
I was working in an Electronics Store when these came out and I remember the first day.
The player was hooked up, TV turned on and Play pressed, pretty much everyone was underwhelmed by the picture, not that it was bad but the owner of the store was big into Laserdiscs and the CED suffered badly by comparison.

The skipping was an issue from day one as mentioned, also there were artifacts in the picture, little sniglets here and there on the screen, not really bad but still disappointing for a format that had such a big build up. It was like "We have VHS why do we need this?"

They are pretty cool in that they are basically a mechanical means of reproducing video!

I have a couple of the discs on display in my living room, mostly because the artwork on the big cartridges looks really nice.

oldtvman
12-12-2012, 02:04 PM
We were an authorized service center and worked on tons of the ced players. If they had introduced it ten years earlier they may have sold more. The stylus were good money makers.

AiboPet
12-12-2012, 02:26 PM
To me...this is astonishing!

A color stereo picture, from a stylus! I guess this must have failed long before it reached Hong Kong....or I was just not paying attention. I've never ever heard of this, and I was an avid LaserDisc fan. I still have my Panasonic player that plays both sides of a Laserdisc...and a few of the discs.

I should some day get that player back on a shelf where I can regularly play it. It worked about a year ago when I last played a Japanese concert (Yellow Magic Orchestra's "Propaganda").

Can't wait till I see one of these CEDs playing someday....no matter how "underwhelming" it looks.

ceebee23
12-12-2012, 02:40 PM
I have both an NTSC and a PAL player (yes they did release a PAL version) .... and a range of disks. The quality is slightly better than VHS with similar resolution but a better signal to noise ratio.

Interestingly RCA found that they sold fewer players than expected but vastly more disks than forecast.

Ironically playing the disks reduces the skipping ..so a new disk may skip but after a few plays the skipping is far less. A good stylus is a definite requirement.

CED was one of those things that I never expected to obtain. The PAL version was only released in the UK. But one day at a party a friend casually mentioned he had seen a weird disk video player in a local electronics store, literally a mile away from me.

This was in the late 1990s.

I rushed around the corner to this shop the next day. The owner had imported a few Hitachi players in the early 80s. So there was my holy grail .. brand new, in its box just waiting for me!!

(In the end I bought his two remaining players and shipped one to Tom at CED Magic in exchange for a US player).

The two players still work beautifully and I sourced stylii on eBay. (A very helpful man in Florida supplied me with them!!)

Blu Ray they aren't but still a pretty amazing technical achievement.

old_tv_nut
12-12-2012, 03:27 PM
The CED format changed the color subcarrier to a lower frequency for better readout, but still mixed with the luminance. It required a comb filter in the player to remove the resulting very coarse dot pattern that otherwise would be visible. The result is that the output had reasonable horizontal resolution but poor diagonal resolution. RCA had some demo material of a car going over a suspension bridge, and you could see the vertical wires, but the diagonal wires tended to disappear.

The sensing of the disc capacitance depending on detuning a resonant circuit that carried a 915 Mhz oscillator signal. This was the same frequency as early microwave ovens, which could interfere with the CED player.

NewVista
12-12-2012, 03:35 PM
Seems all CED discs have good A-list movies on them, the Studios were clamoring to resell films on this format!
The execs at RCA & Hollywood blissfully unaware of the extreme mechanical challenges and reliability issues to soon surface.

Penthode
12-12-2012, 07:32 PM
Yes, depends on TV, some H stability shake, needs slower time constant ?

I had never thought about this before. So the spinning video disc has the same sort of timebase errors as video tape when no timebase correction is used?

Bending or jitter requires a "faster" or reduced time constant. Uncorrected timebase errors from VHS tape needs the reduced time constant horizontal AFC low pass filter so that the horizontal oscillator keeps step with the velocity errors.

I found it interesting to find that negative modulation for North American 525 line TV broadcast required a horizontal AFC circuit to help overcome false triggering with noise impulses whereas older British televisions receiving positive modulation 405 line transmissions did not. I suspect this was because the horizontal sync pulse was at the modulation envelope peak for 525 which made it more susceptible to noise? I recall weak British 405 reception on sets with horizontal AFC locked well under the noise.

old_tv_nut
12-12-2012, 07:48 PM
I found it interesting to find that negative modulation for North American 525 line TV broadcast required a horizontal AFC circuit to help overcome false triggering with noise impulses whereas older British televisions receiving positive modulation 405 line transmissions did not. I suspect this was because the horizontal sync pulse was at the modulation envelope peak for 525 which made it more susceptible to noise? I recall weak British 405 reception on sets with horizontal AFC locked well under the noise.

Exactly correct - with an envelope detector, impulse noise goes toward max signal. With negative modulation, that means it goes into the sync region. Better NTSC set designs included a noise inverter so that impulses going beyond normal sync level would be inverted and go back toward lower signal level (away from sync, towards white). The time constants in the inverter would be much shorter than those in the sync circuit input filter, so the narrow noise pulse that remained would not affect the sync separator.

old_tv_nut
12-12-2012, 07:52 PM
So the spinning video disc has the same sort of timebase errors as video tape when no timebase correction is used?


The disc output is continuous through vertical sync and therefore does not have the sudden offset of H sync timing that is possible with tape - no "flag waving" at the top of the image even with slow AFC, but the smaller random timing variations will be visible.

wa2ise
12-12-2012, 08:15 PM
The disc output is continuous through vertical sync

There was a crude attempt to reduce the time base errors in the CED players. There was a feedback mechanism that moved the pickup stylus perpendicular to the direction to the disc's center. They used what was essentially a speaker voice coil as the driver of this stylus mover. This was to counteract errors due to poor disc centering and turntable wow and flutter. But feedback loops reduce but not completely remove such errors, if they tried they could overshoot and go unstable.

Early CED players used a synchronous AC motor fed by the 60Hz powerline, so the disc would rotate at a speed to produce vertical sync at 60Hz. The color subcarrier was recorded on the disc at around 1.53MHz, and the player would upconvert that to the 3.58MHz NTSC standard, using a beat oscillator around 5.11MHz. The above time base errors would also show up as subcarrier frequency errors, so the beat oscillator frequency was FMed to counteract that, to produce a stable NTSC 3.58Mhz subcarrier.

Back in the day, TV sets' horizontal was designed to cope with erratic horizontal sync from VCRs.

DVD players use digital FIFO buffers and frame store memories, and they control the disc spin rate to keep these buffers and memories half full, and thus produce precisely timed video.

bgadow
12-13-2012, 10:00 PM
I have a couple RCA players and need to get one of them working properly one of these days. Both have belt issues; I think I replaced 1 or 2 belts in the one but then figured out the that main drive belt needed replacement as well. One issue I remember is I couldn't get them to play all the way to the end of a side. A few years ago I used a CED player in conjunction with an old TV(10BP4 era) to do a demonstration somewhere. The machine kept acting up but one thing that came out of it was a guy saw it and asked if I wanted some discs. A few months later he showed up in my driveway with a stack around 4' tall! I could be talked out of the players and the whole stack without much trouble.

The one TV shop I cleaned out was an RCA dealer; I was almost done after many months when I found 3 CED players tucked away. One was truly NOS, never opened; the second was his demonstrator. The third was a lemon that he was never able to get working right. I let them all go on ebay. He said for a while he did a brisk business in disc rentals but it dried up pretty quick.

ChrisW6ATV
12-15-2012, 07:12 PM
It makes me shake my head, but when you look at formats that succeeded and those that didn't, there is a correlation to whether porn was available or not.
That didn't help the HD DVD format, though. Early on, Sony (that controlled the Blu-ray format) said it would not release porn video on Blu-ray, but porn HD DVDs were available pretty quickly after the debut of both formats.

ChrisW6ATV
12-15-2012, 07:21 PM
I have LaserDisc and the only thing I had ran into was anime porn. Yea, not real stuff, just animated. lol
There were definitely numerous "real" porn Laser Discs available. Image Entertainment, now one of the major home-video distributors, got its start by releasing porn discs. At the time, most Laser Discs were made in Japan, which has laws regarding porn if I remember right (and see my comments about Sony, above), but Image contracted with an American manufacturer (perhaps the only one at the time) to make its discs.

Now, I hope people don't get the wrong idea when I seem to know a lot about porn on video disc formats. :eek:

Sandy G
12-15-2012, 07:41 PM
My 1st CED disc was "Dr Strangelove", I think I got it as the "Free" one I got w/the machine. The local dealer DID have quite a good selection of movies, but the "popular" ones all suffered from the annoying "Skip" problem. Actually, the "Soft" focus really WASN'T a problem, it sorta made up for the "Artifacts" that typically showed up on a VHS movie of the time.

wa2ise
12-15-2012, 08:55 PM
There's always the question as to why the CED disc system failed, but DVD was a success. They are both non-re-recordable media you buy specific movies on. DVDs did offer much better image resolution than VHS tapes did, and are fairly small. CED resolution was only slightly better than VHS, and suffered from the skipping problem. And were physically large.

NewVista
12-16-2012, 01:09 AM
Sounds like a good parallel tracking tone arm, I wonder if one of these could be reconfigured into a super phono turntable?

ChrisW6ATV
12-20-2012, 11:47 PM
The Laser Disc format succeed while CED did not, and that was primarily due in the early days to its use in industrial video systems. The consumer adoption took much longer. DVDs were far more popular, and a large part of that success was due to lessons learned in 16+ years of making Laser Discs.

ceebee23
12-21-2012, 12:34 AM
The irony is that my 30 year old CED disks play well but many of my early Laserdisks are completely useless due to "laser rot".

Ironic because LV was promoted as being a format that would not wear out as no physical contact happened between the disk and the player.