Hi, I hope I am in the right forum?!!
I had a rather significant event in life 3 years ago where my house burnt down from a lightning strike. The reason for explaining this is that I had a CCTV system prior to this that was replaced by the insurers at the time. Unfortunately, like with many of these situations it was not smoothly managed and the builder asked the electrician rewiring the house to fit the wires as he had not found a dedicated CCTV expert early enough to do the work. As such, the 'non-expert' electrician fitted the wrong Coax cable and a 'poor quality' power cable to the cameras. The security company accepted the job, and they came in and installed the 4 PTZ HD cameras using the cabling that had been supplied (it was a timing issue as first fix had to be completed and second fix was finished by the time the security company were available).
The problem though was that when the poor quality cable was connected there was no video at all (literally even on a 10m cable there was no video returned). So the builder then subsequently ran the correct coax cable (as directed by the security company). When this was completed everything worked apart from one camera on the longest run (which is roughly 30m) which never responded well to the PTZ commands (by that I mean it only responded to every 2nd or 3rd command and very often would start to spin with no easy way to stop it). I essentially had to accept this situation as I had bigger arguments at the time, and I felt somewhat sorry for the security company as they inherited the problem (even though they accepted the job ... but they accepted it to try and help rather than any other reason). They did test the camera with a separate coax cable run outside to the camera at the time and it worked without a problem. They also went exploring for interference with the coax and found nothing. Also to add, 2 of the camera coax cables run together for the bulk of their journey, with the troublesome cable running a further 7m but there are no electrical cables anywhere near where the 7m of cable is ... the one camera works without a problem suggesting that interference is not the main cause?
Recently though (about 2 months ago) 3 of the cameras stopped working (including the troublesome one). Basically they kept rebooting and at night were particularly bad. After a significant amount of research, I realised that it was probably a voltage drop issue over the dodgy power cable that was still there. And again after research of solutions I found that the best answer was to push 24V through the power cables and then convert whatever voltage is at the other end into 12V, so each camera receives it's full voltage. This has largely worked, as I and a friend did this yesterday and the cameras are all working seemingly as they did previously ... apart from the original troublesome one that if anything is even less responsive now than before.
I was hoping that some wise expert on the forum might know what is causing this and have a simple solution? As a non-expert I thought that possibly the UTC PTZ commands were degrading as well and that a booster (if one exists) might solve this? Otherwise, I wondered whether even the 24V is insufficient to be converted to the 12V at the other end?
I have a HikVision DVR with 8 BNC channels and 2 IP channels (the 2 IP channels are full).
There are 4 external PTZ HD cameras as I have described (I am not actually sure the manufacturer as they are not HikVision).
The original cables were the Swann CCTV cables which were power/Video/control all joined together... I also wondered whether I try to use the control cable with the power cable to increase the size of the cable for power (not yet tried this in part as I will have to solder on a ladder as these cables have been cut back)?
The new Coax cable I don't know what make it is, but it has worked well and was a much thicker and better insulated cable than the Swann equivalent.
Any help will be gratefully received!!