fozzies Posted May 18, 2012 Posted May 18, 2012 If your meter shows video levels then theres half a chance it will show sync pulses. It will probably overlay a squiggly line on the display, and you need 1 volt peak to peak on this squiggle...
Adi Posted May 18, 2012 Posted May 18, 2012 ground loop isolator. I really can't be ar**** with it anymore.
fozzies Posted May 18, 2012 Posted May 18, 2012 Could be that adi. What does the picture look like connected straight through to the dvrs monitor?
MrHappy Posted May 18, 2012 Posted May 18, 2012 but I just need to know why I can see image fine in the office with the balun plugged into my handheld monitor but the same balun plugged into the dvr gives an un-useable image. Simple, a monitor is much more tolerant of your poor quality video signal than your dvr. Try a test camera over the 150m balun run to see if its any better than the wireless link Mr Veritas God
sixwheeledbeast Posted May 18, 2012 Posted May 18, 2012 Simple, a monitor is much more tolerant of your poor quality video signal than your dvr. Exactly. What P2P or Sync values does your tester say?
owillingham Posted May 19, 2012 Author Posted May 19, 2012 Thank you, I had already stumbled on the idea of ground loop inteference and have ordered a couple of filters, if thats not it they'll be useful to have anyway. I'll be trying my colorbar generator over the balun to the dvr when I go back next week to have a look at the cat5 link and try the level meter. I was wondering on the possibility of the signal being too strong rather than too weak aswell and whether a 75ohm termination may be needed. The picture on the dvr was intermittent between no signal and a very grey skewed and fuzzy image. Thinking about the potential of ground loop interference, the yagi aerial on the reciever is attatched to a metal pole attatched to the tin shed, which would be a source of grounding, I may try insulating the pole from the bracket aswell.
sixwheeledbeast Posted May 19, 2012 Posted May 19, 2012 It's better to remove a ground loop problem at source whenever possible. If the levels were too high I would expect the picture to be stable but lack quality. Althought this may depend on the DVR. I know some units will crash/freeze intermittantly if the signal is too hot. Eithier way the best thing to do is check with a SLM at the DVR.
james.wilson Posted May 19, 2012 Posted May 19, 2012 Your baluns should be isolating any grounding issues. As you have said is break it down and see where the problem is first securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Adi Posted May 20, 2012 Posted May 20, 2012 Not nessacerely (however its spelt) ... and thats from experience. I really can't be ar**** with it anymore.
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