james.wilson Posted March 2, 2009 Share Posted March 2, 2009 is the dome earthed ie to case connected to a mains earth or building earth? if so is the coax shield connected to the case as well? isolate that and id bet your noise will go away. unless its a 2060 lol had a few issues with these and noise and the only way we could fix em was to pull em out and use spectra 4's securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
Cubit Posted March 2, 2009 Share Posted March 2, 2009 is the dome earthed ie to case connected to a mains earth or building earth?if so is the coax shield connected to the case as well? isolate that and id bet your noise will go away. unless its a 2060 lol had a few issues with these and noise and the only way we could fix em was to pull em out and use spectra 4's CAT5 Link to comment Share on other sites More sharing options...
luggsey Posted March 2, 2009 Share Posted March 2, 2009 Is it in the form of two horizontal lines filled with wavy lines ?If it is, its sounds like 100Hz hum ( 1 horizontal line would be 50Hz ) and is probably something to do with the power supply. AFAIK the only place your likely to find 100Hz is the output from a bridge rectifier. Could be an earth loop, try adding a loop isolating tranny to prove it, or an isolating balun. Or see if you can physically isolate the camera itself from earth temporarily, including the earth lead in the PSU. What's special about these? Are they plastic encased with no earth connection?? I has never seen one.... ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
james.wilson Posted March 2, 2009 Share Posted March 2, 2009 CAT5 and? the 2060's i had issues with (granted longer distances) were on cat 5 too. Tried everything, in the end put up a test cam and no more problem, so wapped dome. Still no problem. I do reakon however it was coming up the mains whatever it was and thes cams were mounted on a sub station so id assume it was that securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount. Link to comment Share on other sites More sharing options...
Cubit Posted March 2, 2009 Share Posted March 2, 2009 and?the 2060's i had issues with (granted longer distances) were on cat 5 too. Tried everything, in the end put up a test cam and no more problem, so wapped dome. Still no problem. I do reakon however it was coming up the mains whatever it was and thes cams were mounted on a sub station so id assume it was that Def seems like mains hum as it apparently only appears when machines are running. Some old crappy motor giving out a load of noise possibly?? Link to comment Share on other sites More sharing options...
SUBS Posted March 3, 2009 Share Posted March 3, 2009 What's special about these? Are they plastic encased with no earth connection??I has never seen one.... No direct connection so isolates the earth, Humbug is / has become the generic term. It's on Cat5 m8. The picture is fine at the dome, it is definitely interference through the Cat5. A battery powered test monitor isnt earthed, so the effects the same....... signal cable only earthed at one end. Link to comment Share on other sites More sharing options...
ispy Posted March 3, 2009 Share Posted March 3, 2009 come across this before, more than likely cheap baluns but either way you'll need the humbug ve hav ze nolij or if not we ask!!!! Link to comment Share on other sites More sharing options...
luggsey Posted March 3, 2009 Share Posted March 3, 2009 No direct connection so isolates the earth, Humbug is / has become the generic term.A battery powered test monitor isnt earthed, so the effects the same....... signal cable only earthed at one end. I know what you mean now! Bah humbug! ----------------------------------------------------------------------------------------------------------------------------------- Life is like a box of chocolates, some bugger always gets the nice ones! My Amateur Radio Forum Link to comment Share on other sites More sharing options...
alterEGO Posted March 3, 2009 Share Posted March 3, 2009 Is there any welding/steel work close by? Link to comment Share on other sites More sharing options...
SystemQ Posted March 4, 2009 Share Posted March 4, 2009 Def seems like mains hum as it apparently only appears when machines are running. Some old crappy motor giving out a load of noise possibly?? Possibly hit the nail on the head. Could be there are no suppressors and the loading itself is causing issues with the voltage. You could check by putting the DVR and monitor through UPS with a cleaner output. Mains suppression filters would be ok but they would not necessarily even out any voltage fluctuations caused by adverse loading. Paul. System Q Ltd. Link to comment Share on other sites More sharing options...
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