I've gotta say, just getting into electronics a couple of weeks ago and trying to make simple circuits really makes me appreciate the amazing complexity involved in designing something like this. The mind boggles, as someone we know might say.
That things a beast! Also in 1985 Sony released the Sony CCD-M8E Handycam. Much more compact and useable, and in keeping with the small size of the Video 8 cassettes.
Shoulder-mount cameras still exist. :) I work with HD ones at the television station I work at part time. They're still nicely modular, the tape transport on one of ours broke, so we just ordered a new one and installed it ourselves. They also have replacable cards for various encoders. You don't see them much in consumer cameras, but in the professional world they're alive and well.
I used to fix these things back in the day. The pots labeled LP adj were for long play adjust and there would be an SP adjust. If memory serves they were for centering the tracking. These things were a beast to repair and a lot of them had notorious surface mount cap issues. The red button on the front that you did not know what it did is just another record/pause button. It did the same thing that the one that would be under your right thumb did. A previous poster explained the delay line.
I really enjoy these tear downs anyway, but this is especially fascinating to me. It takes me right back to watching my father run television, vhs and other A/V repairs when I was a young child. Everything discrete with practically no IC's. The smell of soldier and huge 3 inch diameter electrolytics capacitors... Wonderful stuff!!!
this is so awesome mister!!! I just happen to buy one for 200$ complete set w/ suitcase, original battery, i found a replacement battery, got the charger, instruction, spare tapes, but only the RF unit missing, but fear not i'll modify it to RCA outputs! thanks to your video, i'll be able to have a pre inside look before taking it apart, mine has issues with the motor section moving the lens and autofocus lens. :D time for beer and click play
My dad bought one and I have it now......Still works just fine. Yes it's heavy and bulky but fun to play with. Battery's are getting hard to find so I got a variable wall wort from radio shack to power it.
Delay line is a scan lines timing scheme, Mechanical scanning of video lines using a rotating video head have inaccuracies, So the scan lines are delayed and released at a steady pace to have them stacked vertically with perfect timing, Modern analog camcorders had a line TBC using digital memory, so the lines are converted to digital, stored in a memory and released using a digital clock then converted back to analog and output using composite or S-Video connectors.
I've also heard of them being used to delay the video one line so that when the tape is scratched and the video drops out, the last line is displayed instead of black. The last line is certainly a better approximation as to what should be displayed compared to black.
Re the glass delay line. The PAL system requires a device to delay one scan line of video for colour phase comparison (PAL - Phase Alternate Line) hence unlike NTSC there was no tint control needed on PAL TV’s. Alternately the signal path for Chroma and luminance signals was different meaning a small delay might be required in the luminance signal so it remained in sync with the Chroma information which has a longer processing path to avoid the Chroma being shifted to one side of the image .
I believe the delay line stores the chroma signal between the odd and even half frames, so that the color of alternate lines can be averaged to reduce the hanover bar artifact.
Delay lines where also used as an simple error correcting system. One line of video is stored in the dclay line, and if there was a signal dropout from the tape, the signal from the last line was used instead.
I used to fix these for the rich kids' parents when I was in high school. But that was after several years of repairing VCRs (started that in junior high).
The red photo sensor in the tape transport mechanism does not only detect the presence of the cassette. It also tells the VTR when either end of the tape has been reached. For fast forward or rewind this is critical, otherwise the tape could be stretched or snapped at the end of the spool. To tell the sensor when the end is reached, all tapes have a length of clear leader tape that the light beam can shine through.
@EEVblog: The delay line was used to sync up the video with the reconstructed horizontal sync. The video and the H-sync were separated from each other and recorded to different parts on the tape.
I remember my dad having a zenith betamax camcorder back in the early 80's. It had a separate recorder that you would hold on your side with a shoulder strap. The camera was huge and the recorder and battery was heavy
Hi Dave, I didn't realise they are so sort after until I looked, So for now I would like to keep hold of it. It still works with all it's VHS-C goodness... I've just seen a couple on E-bay ...
Delay line is probably for compensation chrominance path delay to meet with luminance signal which was faster due to less processing. This device wasn't work on separate RGB signals instead signals for colors were coded to PAL system and recorded on the tape. So delay line is a part of PAL coder...
Cheers Dave. It'd be nice to see the CCD sensor in another vid. Man, I wanted one of these camcorders so badly when I was a teenager but at £1200 I could only dream.
Mine is Hi-8 and the user's manual says 440 lines in standard mode and 320 in LP. Unfortunately there was a problem with the SP mode when the camera was paused during recordings... Never used it much...
There still used in modern portible large board electronics SOMETIMES when a flex cable is to sensitive or small and vibration is a factor where a socket would end up having problems in the long run. but the more modern ones atleast genrily are able to be pulled apart with a tool.
EEVblog I think it did have a macro-function, it usually was in the knob on the zoomring (The Panasonic MS-1 at least had it this way and was able to focus so close you could see dust inside the lens :P). Not that it matters anymore, but usually you could pull it out or press it in when nearing the wide-end of the zoomring, which would allow you to focus much, much closer. Some of the cheaper Fujinon lenses for ENG camera's still have the macrofunction on the zoomring.
Just thinking that the whole block for the tape has been replaced with a single SD-card slot without any moving parts nowadays, shows how everyone can now afford gear that 20 years ago not even TV stations could have.
I think i have a clue how that auto focus might work.There should be an IR diode somewhere over or under the lens of it. As the IR light bounces of something you're trying to focus at, it comes back at an angle, beacuse the emitter is not exacly where the reciver is. And so, the device can find a strongest IR light with that photosensor by moving it up or down. I'm not sure if it works that way here, but i'm sure that's how modern IR distance meters work.
Not the actual model featured in the movie. Promotional consideration for Doc Brown seeing his future self on video was provided by JVC. "This is truly amazing, a portable television studio. No wonder your president has to be an actor, he's gotta look good on television!"
That one is built a lot nicer than the ones I've taken apart. Those viewfinders are useful when you need a small screen. I have used them in several of my projects. Most of them just take 5v power and a composite video signal. I like those hinged connectors. Are those available anywhere or are they custom?
I have a Panasonic Omnivision, bit chunkier, and recorded to VHS, it looks amazing even with today's techonology. I think it was made after this camera, or maybe it just worked better than the Video 8.
240 lines is line-pairs! So, a HD screen with 1920x1080 resolution, at best, could do 960 line pairs. All of that is limited by optics and bandwidth. Beautiful camcorder though! Thanks! :)
DELAY LINEs... i once found quiet a couple in our old JVC VCR from the 80s too!!! not SMD in my case. But when i opened them up to look whats inside, i was quiet surprised!!! looked like "glass" with contacts to me back then. Todays guess would be, its made from quartz cristall. but how do they work ?! still a mystery to me
I remember my parents paid about $1,000 USD for a cheap Sears VHS camcorder in the same time frame. No telling how much this Sony cost when it came out...
So Dave, ifound your videos yesterday and im really enjoying them. i am a teenager and i am really interested in electronics and would like to be a electronics engineer one day. i am pretty early in my learning but i understand alot of your videos. i have kind of run out of ideas on what to build. is there anything that is cheap and easy that you would recommend for me to try building that i would learn alot from?
I have a videocamera with full size vhs tapes from a similar year. Amazing piece of kit, still use it for my channel now and again :o) Proper microphone, better sound than my hd handycam :o) Lol, love the software bug ;o) Wow, love the 80s watch ;o) I dare you to try and put it back together!! ;o)
