Video Balun Problems Please Help

[CompostCORNER]

I visited a recent install where 5 cameras from a 4amp 12vdc PSU, 4 had atrocious interference. The 5th camera was cabled in 'shotgun' and seemed immune to the interference. I brought in further PSU's to swap the initial one out, and fitted humbugs and found that very little helped. In the end, I found by percerverence that when I fitted 5 x Computar 12vdc 1amp PSU's, one dedicted to each camera, then the interference vanished.

[SUBS]

I visited a recent install where 5 cameras from a 4amp 12vdc PSU, 4 had atrocious interference. The 5th camera was cabled in 'shotgun' and seemed immune to the interference. I brought in further PSU's to swap the initial one out, and fitted humbugs and found that very little helped. In the end, I found by percerverence that when I fitted 5 x Computar 12vdc 1amp PSU's, one dedicted to each camera, then the interference vanished.

Used to see crosstalk a lot with early board cameras used in PIRs etc that had inadequate decuopling, if you shared a PSU, But Later ones dont seem to have the problem so much. But yes, if theyre cheapo cameras, or old ones, its a possibility.

you could prove it by powering them up one at a time, see if theres crosstalk with 2 powered up - you could probably actually see both images - which will get worse as you add more cameras.

[mitsifto123]

Might to some extent depend on the camera, but to power a camera, over one pair of a cat5, 50 metres is a hell of a long way.

I think you'd be better off buying decent baluns, which should isolate anyway, such as NVT rather than adding a humbug, probably a cheaper option as well.

hi,

can u please point me in the right direction for the NVT baluns, you can message if you want to avoid giving out company names.

thanks in advance

[Cubit]

hi,

can u please point me in the right direction for the NVT baluns, you can message if you want to avoid giving out company names.

thanks in advance

Where abouts in W. Yorks are you?

[mitsifto123]

Where abouts in W. Yorks are you?

based in Leeds

[CompostCORNER]

you could prove it by powering them up one at a time, see if theres crosstalk with 2 powered up - you could probably actually see both images - which will get worse as you add more cameras.

Yeah. We did that. as a second cam was added, black rolling bars appeared. (the benefits of walkie talkies lol). We tried different combinations of these 4 cameras and the PSU's and still the same. All cameras were 12vdc antivandal fixed domes. 2 old, 1 not so old, and 1 brand new. All 4 cams were of different type. Place has been open for a good 5 years and the sub said those 4 had always been bad pictures. The odd thing is that these types of cameras are also in use elsewhere on site and operate fine on their respective 4amp 12vdc PSU.