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Sony EVS700 VCR, head drum UK / USA compatibility?

Discussion in 'Electronic Repair' started by N_Cook, Oct 16, 2013.

  1. N_Cook

    N_Cook Guest

    Would an electronically dead USA machine be a suitable "parts mule" for
    a UK machine as far as the video head drum is concerned? NTSC v PAL make
    a difference to drum or heads physical dimensions or head posistioning etc ?
    Required to retrieve sound from tape archives when the PCM , 6 channel
    audio option ,was used instead of for video use
     
  2. Guest

    In this case I would just give it a shot.

    When I saw the noise bands produced playing a tape that had video but was overrecorded with audio on maybe tracks 3 and 4, it looked digital. You would think it some sort of frequency modulation or something but I doubt it after seeing that. If it is FM, there are only two frequencies involved.

    America could be a good source for that part because it is a throwaway society. People are already forgetting what recording tape even is (was). Phones take better video than camcorders usually did, with certain exceptions maybe.

    You may find that the thing works perfectly. The price should be right in the US, there might even be someone giving one away on Craigslist or something. The problem is shipping. It would be alot better to have someone who knows what they're doing pull the drum, pack it properly and ship it to save on that. It could just about go mail. The whole unit on the other hand would take a box and all that shit.

    I imagine with the 1500 vs 1800 RPM disk speed, the audio tapes across the pond would be as incompatible as the video tapes.
     
  3. Guest

    I don't know if this is true for consumer machines but analog broadcast machines use wider heads for PAL to make up for poorer carrier SN ratios from slower drum speeds.

     
  4. Guest

    It is unlikely they have different azimuths or even track widths. A slightly different track width would optimize between the two systems but they probably didn't due to cost. (probably) Even if they did it should still work well enough for what you need.

    If the linear tape speed is the same and the RPMs are lower, I would say that if anything the UK tracks are wider, which should not be a problem except it might have trouble picking up the ATF signals. I still doubt it because IIRC the ATF signals are a lower frequency than the actual carriers.

    These things have to have some bandwidth to record color under, and both systems do that. Stick one in and try it.
     
  5. Guest

    "but analog broadcast machines use wider heads for PAL to make up for poorer carrier SN ratios from slower drum speeds. "

    You got in edgewise, that last post was an addon. Anyway, there is also ROOM for wider tracks which will improve the quality. The question is whether they bothered in a consumer machine. They don't pinch pennies as much on commercial equipment.
     
  6. N_Cook

    N_Cook Guest

    Unfortunately the desoldering part of drum removal is more awkward than
    any of the video heads I've removed over the years, so probably the
    whole machine shipped over
     
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