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  • EEVblog #375 – Sony Video 8 Camcorder Teardown

    Posted on October 24th, 2012 EEVblog 15 comments


    Go Back to the Future with Dave to 1985 as he tears down the world’s first Video 8 camcorder, a vintage Sony CCD-V8AF.

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    • Bob Weiss, N2IXK

      Bad ’80s flashback! Man, I hated working on those things! :) First real electronics job was working in a TV/VCR shop right about the time this thing was in it’s prime. I think camcorders were the first consumer product to really adopt SMD components. Of course, that thing looks positively spacious inside compared to an iPhone or whatever..

      The opto thingy sticking up into the middle of the cassette is a dual infrared LED, which emits out to both sides. There are sensors on either side of the cassette housing, which are used to detect the transparent leader tape at the ends of the cassette, so the unit knows to shut off the motor and go into stop or rewind mode. Some of the sensors would get fooled into operation by ambient light when you had everything open on the bench, causing you to have to shade things with a hand or a empty tape box while testing.

    • SD

      About your comments on the soldering. Due to the glue and lousy soldering I bet that was wave soldered.

      I think the delay line is a normal part of PAL video decoding(but I am only familiar with NTSC).

    • Chris

      http://en.wikipedia.org/wiki/Delay_line_memory
      Scroll down to “Piezoelectric delay lines”. its part of PAL decoding

    • TVguy

      The glass delay line was needed for chroma crosstalk cancellation. High density video tape recording (no guard band) needed a two line delay due to PAL switching (NTSC uses a one line delay). I love those tiny CRTs used in viewfinders

    • http://www.christianseifert.net Christian

      Hi Dave,

      on the net there are many hobby electronics applications for these old camcorder B&W viewfinder CRTs. For teardown part two please check the function of the crt.

      Check this art project:
      http://instacrt.com/

      Many greetings from Hamburg/Germany
      Christian

      • http://www.eevblog.com EEVblog

        That’s cool!

    • Rafael Souza

      Man, this is from an era where Sony churned some of the most desired and advanced consumer electronics in the world… The Apple of its day, although without the idio… ahem… fans waiting in line for their new product.

      This is an incredible teardown that showcases the then widespread idea of “board replacement” (in contrast to board repair) and “disposable electronics” (in contrast to repairable products)… As Bob Weiss mentioned above, these things were deemed impossible to repair by the average hobbyist like I was… :)

    • Steve K

      To add to the delay line discussion, there are two separate uses for them in the products I’ve seen.

      First, they are used to match up the timing between the color and B&W signals. At least with NTSC, the color signal is band limited to 500KHz whereas the B&W signal could be great than 4MHz. The bandpass filters on the color information introduces a delay. The delay line is then put in the path of the B&W signal so that both has the same time delay. Othewise, there would be s shift between the two on the TV screen.

      The second use was in the comb filter. I believe the delay you point out was in the section mark as comb filter on the PCB. Back in those days, a comb filter was created when you took the original signal and a delay signal (via a delay line) and sum the two. It was primarily used to separate the color and luminious signals from the composite signal.

      Anyway, as others pointed out, this is probably a PAL system which may be totally different from NTSC which I used to work on.

      • TVguy

        Hi Steve K,

        The delay of the luminance signal was needed in TV receivers to match the chroma and luminance timing as you have stated (both NTSC & PAL). The luminance delay line was essentially a transmission line (coil with distributed capacitance). Comb filtering with glass delay lines was an analog method of Y/C separation that did not compromise luminance bandwidth. As stated previously the 2H glass delay line was only used in playback for chroma crosstalk cancellation. It was often referred to as a comb filter due to its peaked response at 4433618.75 MHz. Another cool thing about the Video 8 system was its auto tracking system that relied on pilot tones recorded on the tape to ensure head/track alignment (no control pulses needed). BTW I still has a professional Video 8 deck complete with in built digital timebase corrector; I use it for transfer puposes for customers who no longer have working cameras but many tapes they wish to migrate to another format.

    • Andrew

      Dave, you sound sick.

      • Virology Troll

        Picornaviridae, gotta catch ‘em all!

    • http://www.eevblog.com/ Jan

      The best thing is the turntable made of plexiglass at the beginning of another good blog from you :-). Thanks Dave.

      • http://www.eevblog.com EEVblog

        I do enjoy the turntable!

    • http://laserninja.net laserninja

      Nice,
      I also enjoy teardown of gadgets…
      Thanks…

    • Bill Clay

      So what video camera did Marty use to record the Doc at the Mall in the first movie? Sony Video 8?