Bonus teaser video--Early Laserdisc Player
Added 2018-01-17 22:39:55 +0000 UTCThe last couple of weeks haven't let me spend too much time on content creation. In light of that, I thought I'd share with you some unedited B-roll footage that will be in my next video.
I'm not explaining anything at all in this clip as it is after all B-roll, so here's an overview of what's happening:
The first attempted disc is of the Producers, a CLV disc. Notably the machine does not advance the laser's position and simply reads in the same spot, but it does slow the speed of the disc down according to its position along the disc. This suggests that its logic circuits for controlling the disc speed are intact and working.
The second disc is a CAV disc of the Aristocats, which it has a much better time playing. It does "play", but it advances way too fast. You can hear it attempting to play the audio, but it is very scrambled.
The index display also works, and notably on the Producers disc it was able to figure out where it was along the disc (it showed the correct time). However it does not show the frame number on the Aristocats disc.
One day I want to replace as many capacitors as I can and see if that might help to get it working, but the laser system is so ancient and frankly experimental that it likely won't ever work. But who knows!
Comments
Who needs seashells to hear the ocean when you've got this baby rocking in the living room B)
avfusion
2018-01-18 04:05:25 +0000 UTCI had a personal CD player in the 90's that did some weird things similar to this. It refused to play without massive skipping all over the place, but if I placed it on its side with the laser carriage vertical, it played just fine.
Quinton Wilson
2018-01-18 00:23:04 +0000 UTCThat player coming up to speed sounds like a 1950s-era Ford pick-up with straight cut gears. Amazing!
Roger Beal
2018-01-18 00:16:19 +0000 UTCIt's funny you bring that link up, because I've read that whole thing! Mine is in pretty much the exact state his is. And yes, I do plan on doing a teardown and exploration of it. It's so prototype-y in its construction it's almost funny!
Technology Connections
2018-01-17 23:39:03 +0000 UTCOh wow. I'd be super interested in seeing the guts of this thing - any plans to do a peek-inside (likely not a teardown of course)? Anything like this? <a href="https://www.repairfaq.org/sam/odfaq.htm" rel="nofollow noopener" target="_blank">https://www.repairfaq.org/sam/odfaq.htm</a>#odmagvch8000 and in particular <a href="https://www.repairfaq.org/sam/pr7820o1.jpg" rel="nofollow noopener" target="_blank">https://www.repairfaq.org/sam/pr7820o1.jpg</a> ?
Matt Falcon
2018-01-17 23:31:27 +0000 UTCYep, the Helium-Neon laser tube is working fine. What's likely to be the culprit is the optical system used for fine tracking. The laser carriage in this thing is massive--pretty much the whole width of the unit minus the distance the laser travels. The entire carriage slides when moving the laser. I believe this old system uses electronically controlled mirrors inside the carriage to maintain the laser's focus. The objective lens (if I'm calling it the right thing) can move up and down, but without disassembling the optical system I can't tell if the mirrors are actually moving. That may explain why it plays the Aristocats too fast. The belt on the coarse tracking had disintegrated, and I found a semi-suitable replacement. It doesn't smoothly go backwards, though, which is the reason I needed to keep pressing reverse over and over again to bring the laser back to the start. It can't do it on its own.
Technology Connections
2018-01-17 23:28:16 +0000 UTCoooh... interesting. Well, seems like the laser is working, it's picking up an image. But it's out of sync... so that's why it's fluttering and screwing all over the place. Seems like there must be something in the player that fine-tunes the rotation speed once it picks up an image, and picks up the scanlines/frame markers encoded in the disc. Not picking up those markers = not fine-tuning the spindle speed = playing like this. Maybe the laser pickup has a gain adjustment? Maybe the rough-tuning of the spindle speed is too far out of whack to fine-tune adjust on its own?
Matt Falcon
2018-01-17 23:21:24 +0000 UTCthanks
h.drew foy
2018-01-17 23:08:33 +0000 UTC
