Just like with the old analog cameras, I believe the TVI/CVI/AHD cameras can suffer from ground loop noise if the installations are done using wire that is not coax.
One ground loop balun should solve this issue. Sometimes two might be needed, but that is on larger installs and should be used when cameras are quite far apart (at least, that is what we had the best luck with)
IPVMU Certified | 09/11/16 09:33am
I have only done one installation with this product. I also had one or two cameras that had some interference in the form of rolling bars.
I guess I am still confused how this technology works. Is there something about it that is supposed to prevent this from happening? Is it a digital picture or is it technically still analog?
I had an issue on one very small 4 camera installation with LTS TVI cameras,
When they were first installed I did not notice any noise, the 3 of the runs were very short 15 feet at the most, 1 of the cameras developed some noise. LTS sent a power filter (no cost) to resolve the issue, which it did. I have not had an issue that I had to use a ground loop isolator on the coax.
Update: Member says the noise is on Cat 5 cables, not coax.
I have never used TVI baluns, but on additional information when I had the noise issue , all cameras were powered from the same power supply- typical siamese cable installation.
I published an article in my website about the correct use of UTP cables and balluns in CCTV: http://www.cctvinstitute.com.br/cabling---part-4---utp.html
IPVMU Certified | 09/28/16 07:52pm
I had a couple cameras giving me the rolling bars.
The cameras were using Siamese cable and all powered from the same power supply.
I eventually powered them on a different power supply and it all stopped.
I believe it was a ground loop issue through the power cable.
A ground loop isolator may also have stopped the problem.
This is one reason I like IP cams, I have yet to fight with ground loop problems when using them.