[Problem With Video Over Cat5e Using Baluns]

We had a similar problem at a site where we later found there was a serious mains earth fault-

there was no earth, it had corroded. (

We had problems with picture rolling and distorting (partly solved with isolators).

Good earth stakes on the mains supply in each building solved the problem for good.

Thanks Ard, also sounds plausible. Will contact my client to have all the mains electrical plugs rechecked.

[Problem With Video Over Cat5e Using Baluns]

the 'clue' is in that it works ok to the crt, had you not mentioned it already, would have advised to try that test 1st.

dvr's are far more 'fussy' about the signal stregnth and quality received than a crt, being digital the 'flyback' syncing is more critical, a weak signal often upsets the time base when stronger signals are available on other inputs and displaye at the same time.

so my guess is you will need active baluns on the affected camera's, choose ones with variable video gain adjustment, or fitting an adjustable video amp at the dvr end might fix it, and worth a try if you have one to hand.

regs

alan

Thank you Alan will give that a shot...........

[Problem With Video Over Cat5e Using Baluns]

Good day all. I hope someone can shed some light on this for me. I have a client who has done CCTV installation where they have installed ove 64 cameras. They are using Cat5e for all the cable runs and in some cases have 4 cameras running on one length of cat5e cable ( thats using 1 twisted pair per camera.) Now the problem they are having is that on a certain run where they have 4 cameras on the cat5e, 3 of the cameras out of the four were distorting, as if power interference. I.ve sent him cat5 ground loop isolators and this has somewhat cleared up the picture although he stilll has 5% of the top of each picture distorting. Strangely thouh this only happens when he plugs the cameras into the PC Based DVR but when pluged into a standard CRT/ CCTV monitor the picture is clear even with out the ground loop isolators. They'vetried re running new cable, changing the powers supplies and swopping the cameras around, but just on this cable run they have thsi problem of the distorted picture. What can be the problem and how can it be resolved. Any assistance will be very much appreciated.

Thank you....