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Horizon

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Everything posted by Horizon

  1. Horizon

    help please

    Hi ack1234, you've got to have patience - some of these folks don't do weekends, others are on different time zones. Also some can't or won't help, because they can't or won't help You should also say what make and model of switcher or mux you have, so we can check it's features, and admire or ridicule as appropriate. My guess is that you already have a mux. To get it to work, you need to connect the video out of the VCR into the VCR input at the back of the mux. There should be a BNC for this labelled "VCR in" or "time-lapse in" or something. Don't connect it to one of the eight camera inputs. Connect your monitor to the "spot output" or "monitor output". There might be a switch to select either live or recorded video. This should work, at least it's how my crusty 9 channel Samsung is supposed to behave. As I understand it, the mux sends each of the 8 camera images to the VCR one after the other, each tagged with a code to identify which image belongs to which camera. The VCR must be played back through the mux, so the code can be read and the images sorted into their correct order. This allows you to select one of the images, or a group of them for display. If you hook the monitor straight to the VCR, the monitor displays all of the images at once, which explains the problem with your two cameras. A switcher just switches between all cameras after a time delay. For the swicher, you'd connect the monitor to the VCR without a problem. It doesn't sound like you have one of these.
  2. Hi folks. Since composite video has a frequency range of about 50Hz up to around 5 MHz, the cable TV splitters won't be much use - it'll behave like a BNC T-splitter. To use multiple monitors you generally use T-splitters and turn off the 75 ohm terminators in all but the last monitor, or use a distribution amplifier as shown on xellbuy's link. Most TVs don't allow the termination resistor to be switched out of circuit, in which case you have to open the TV up to unsolder it (and void the warrantee). Best bet would be the distribution amp.
  3. Horizon

    CCTV resolution question.

    Hi folks. This is an analog camera? Because it is kind of a tricky/interesting question. You'd really want to know what the camera's resolution is in TV-lines (TVL) - how many black and white (white being the other "line" between the black lines) it can resolve. A lot of cheapy cameras are being sold based on the resolution of the CCD imager (where the lens focuses the image). The 795*596 that jonohanson quotes refers to the number of pixels on the CCD, but the camera still has to convert this to an analog signal to send out throught the BNC connector. The resolution for analog video is measured in TV-lines. If the camera maker has cut some corners with the A to D converter, or the optical parts like the IR filter, there can be a noticeable difference in quality between cameras with the same CCD sizes. Anyone else's thoughts?
  4. Horizon

    ACD 1500 Failure - Need to disassemble

    G'day Rick. My suggestion is that once you've managed to pull the camera apart, take a look for faulty capacitors. They'll look something like these http://en.wikipedia.org/wiki/Capacitor_plague they may have dried out and failed when the camera overheated. If the top of the cap has become domed, then it needs to be replaced. See if you can find where the power supply is. The capacitors around the supply are under the most stress, and tend to fail first. Good luck!
  5. Hi Webmanny. Your blue connector looks an awful lot like a centronics connector. Use to see 36 pin versions of these on printers. You could mail-order one or (ahem) solder straight onto the pins Generic Centronics drawing: http://www.farnell.com/datasheets/382722.pdf You'll need to measure it up to be sure. The 14 position version is what you want. I don't know what the other 7 pins are for. Unused? Also, those diamond shaped finger lock things can be pulled off with pliers. The video + and - probably has to go through a balun back at your DVR. R + and - are for the RS422 control, and the end two are for 15V DC and ground. I suspect this dome is designed to be wired up with CAT-5, with one twisted-pair for video, one for RS422, other pair for power, and the last spare. The unit can also run off 24V AC, the writing is sort-of readable. A 15V power supply, with maybe 2 amp fuse would do. Or use 24V AC for longer distances. Oh, and if you haven't found it already, here are the specs: http://armelectronics.com/specs/SPEEDOME_SERIES.pdf Looks like a nice camera! Edited to add Cent. PDF
  6. Horizon

    DVR output using CAT5

    Hi third-eye. I've no practical long distance experience with baluns and CAT-5, but from a theoretical point of view... (Oops, it's going to be wordy.) First up you don't want to parallel up the twisted pairs in the CAT-5, you'll want to use only one twisted-pair, such as blue and blue/white. The reason for this is that it will cause an imedance mis-match through the balun, and part of the signal will reflect back and forth at the baluns - the signal will be distorted. As birdman says, they need to be connected the same way at each balun. It must be one pair - not parts of different pairs (like using orange and blue). You need the twisting for the impedance, and protection from interference. The local monitor at the DVR should be either disconnected, or set to unterminated, or high impedance (Hi-Z). If it isn't you'll have the wrong impedance there, and get reflections. Probably easier to leave it disconnected, and plug the balun right onto the spot out terminal. At the other end of the CAT-5, go through the balun, then straight into the composite video (yellow connector) on the TV. So hopefully you have: DVR --------------> Balun -----------------------------------> Balun ---------------> TV 75ohm out 75 to 100 ohm 150m of 100ohm CAT-5 100 to 75ohm 75ohm (one pair) The TVs always have a 75 ohm input for the composite video. Err, good luck? Cheers
  7. Hi Dee. Just stumbled across your posts. That's a nice set up you've been putting together there. About the erratic PTZ behaviour; I noticed in one of your photos that you have miss-wired the RS422 connection between the DVR(?) and the decoder board. I'm not sure whether you have already corrected it, but D- and D+ must only use one twisted pair. Otherwise the signal will be susceptible to noise, which could cause the erratic motion. So for example, D- uses the blue wire, D+ goes to the blue+white wire.
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