VGA to 5 BNC?

Discussion in 'Home Theater Projects' started by ChristopherDAC, Aug 18, 2006.

  1. ChristopherDAC

    ChristopherDAC Producer

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    Just what the title says. I want to connect a video processor with RGB HV outputs via five BNC connectors to a display with a standard "HD-15" VGA input connector. Since the signals are the same, I need some kind of adaptor cable. Any idea where to get one, preferably inexpensive?
     
  2. David_Rivshin

    David_Rivshin Second Unit

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    Such cables are normally used for connecting computers to higher-end CRT monitors (for slightly better quality than an HD-15 connection), so you normally find them filed under computer equipment.

    Here's some I found real quick: http://www.monoprice.com/products/su...02&cp_id=10203
    (note that some of those are 4BNC, but you probably want 5BNC with the separate H and V-sync signals)

    You might even be able to find one locally in a CompUSA or BestBuy type place if you're in a hurry, but I'm sure it'd be pretty overpriced.

    Happy shopping [​IMG]
    -- Dave
     
  3. ChristopherDAC

    ChristopherDAC Producer

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    Actually, looking at the piece of equipment, I found (to my chagrin) that it was actually 4-BNC out, RGB and Composite-Sync. I'm not even sure whether it's possible to one of those through an adapter to a VGA monitor. Probably a moot point anyway, since it looks like it can't be used for anything anyway — it's controlled through a SCSI interface, undoubtedly using a proprietary and now-unavailable driver, so I don't think I could actually use it if I did get the adapter. That's one of the perils of hunting at surplus shops!
     
  4. David_Rivshin

    David_Rivshin Second Unit

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    That sounds like a very interesting piece of equipment, to be a SCSI device with it's own video output.

    I honestly wouldn't be terribly to find that most equipment could handle composite sync just fine. Many a monitor with 5BNC inputs is actually labelled to indicate where to hook up a composite H/V-sync signal. Of course I haven't tried hooking a 4BNC up to VGA myself, so such advice comes with no warrantee [​IMG]

    As for the SCSI interface, the SCSI specs include generic command sets for many common device types. So many normal devices such as hard disks, optical media drives, tape drives, etc, work just fine with no special purpose drivers. See www.t10.org for most of the gory details, including the nice diagram below. So you might just get lucky, depending on what type of device you've got there.
    [​IMG]

    -- Dave
     
  5. ChristopherDAC

    ChristopherDAC Producer

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    Hunh. It's a very strange object, exceedingly heavy, and the name on the box is somehting like "RGB-View". The only control on it is a power switch on the front, and the back has a small [4] DIP-switch marked "SCSI Mode" or something of the kind. There is what is marked as "High Resolution Input", which is RGB-C, and "Low Resolution Input", two BNCs [maybe one with a loop-through?] for composite video, one S-Video connector, and what I think was a 9-pin PC monitor connector ; "High Resolution Output", 4 BNCs just like the input, is the only output. There are two "control" inputs, one a 25-pin RS-232, and the other SCSI.

    It's just a video processor, as far as I can see, but it's computer controlled. It appears to have been used to feed a Barco projector through some kind of switcher. Overall, a mystery. Incidentally, thanks for the chart.
     
  6. David_Rivshin

    David_Rivshin Second Unit

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    Well, most of that makes sense, except for the SCSI part. I can understand using RS232/RS422, or even MIDI, to computer control such a box, but SCSI is a new one on me. I suppose you learn something new every day. Could it be perhaps that the device acts as a SCSI scanner, and allows some form of video capture via the SCSI connection?

    The only 9-pin (presumedly D-shell) video connections I know of are the (now very) old MDA/CGA/EGA standards, which would seem to be the wrong decade of electronics. I would assume it's just a serial port, except that it wouldn't make much sense to have a second one.

    Speaking of which, if you just want to control the device, I would think the RS232 port would be the preferred method. It was probably intended to be controlled by a Crestron system or the like, so you might even be able to figure out the command set. Using any simple terminal emulator should do the trick, assuming it speak ASCII.

    If all else fails, you could always just use it as a desk ornament and offer prizes for whoever can figure out exactly what it is [​IMG]

    -- Dave
     
  7. ChristopherDAC

    ChristopherDAC Producer

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    Oh, it's about the right age for a CGA connection, I think, which would explain the "low resolution" bit. The box, you see, is about the size of a LaserDisc player, and if anything heavier. It looks like a relic of the '80s, of a kind which probably sold for thousands when new. I guess it could concievably have a video capture function, or maybe was intended to allow display of hi-res CGI from a Silicon Graphics workstation or the like. Maybe I'll decide to go after it one of these days [no way it's going to sell], and try to operate it via serial interface and a null-modem cable.

    Too big for a desk ornament, I think, although I did happen upon a "Generation X TV Box" at the same dealer's, which is a dongle for taking a MAC monitor output and putting out a standard composite video signal. That's about the size of a paperweight.
     
  8. JeremyErwin

    JeremyErwin Producer

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    Might well be a device for overlaying computer graphics onto video.
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    To answer your original question, you just need a VGA to 5xBNC breakout cable.

    These are available as short breakout adapters with female BNC plugs so that then you connect a full-sized BNC-BNC coax between that and your display, or as a single custom cable with mini-coax with a VGA plug on one end and male BNC on the other. I recommend the latter for short distances, and the former for long distances.

    you can find these in many places such as:

    http://bluejeanscable.com/store/rgbhv/index.htm

    http://www.ramelectronics.net/html/hdtv-cables.html

    I use an extron breakout cable and then 30 feet of belden to my CRT display which takes 5xBNC, in case you're curious.

    hope that helps!
     
  10. joopiter_89c

    joopiter_89c Auditioning

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