AHD Camera with Night Time Hum Bars

[JW_LEES 0]

I am using a 4 camera AvTech AHD system which worked fine using standard cameras, I recently upgraded two of the cameras to AHD, all is fine during daylight but one camera is picking up rolling hum bars at night. I swapped it with the other new AHD camera and the problems is the same, I also re-routed all the coax cables so that there is no mains cables in the vicinity for at least 2 metres.

But no change, all the cameras are bolted to brickwork. I have noticed that this camera is located between two small satellite dishes approx. 0.5m either side. Has anyone experienced RF interference from sat. dishes ?

John

[the toss 0]

What type of coax are you using ? RG59 , RG6 , mini coax , pre made ?

[JW_LEES 0]

Hi, I am using pre-made coax with BNC connectors

[JW_LEES 0]

Do you think a ground loop isolator would be any use ?

[the toss 0]

Only if it IS an earth loop. As I've posted many times in this forum , noise issues can be a nightmare to solve but the first two things you can do to minimise the chance of it happening is to use a good regulated power supply AND good proffessional quality coax. Most pre-made cables are nothing more than shielded audio cables and this is your most likely source of noise

[JW_LEES 0]

Many thanks for your advice, I am going to move the camera to a position with no sat dishes or alarm boxes near bye and see what happens.

[JW_LEES 0]

Hi, I have moved the camera about 1.5m from the sat dishes and alarm box. The problem is greatly reduced and is now bearable, so it must be interference from one of the other devices. Many thanks for your help.