newbie here

[truckracer 0]

Hello to everyone here, I am a new guy and have always used traditional rg-6 for video transmission. A long while back when I discovered that video could be transmitted along cheap cat 5 utp I got very interested.

 

Since so many buildings and homes now days have extra cat 5 cables ran as part of the infrastructure wiring, this would make my job so much easier.

 

I was playing around here at home with a run of about 200 feet of cat 5 also providing 12 vdc.

 

I used the orange pair for power and the blue pair for video.

I DID NOT use a video balun.

 

surprisingly enough while observing polarity ( although I know this is an impedence mismatch), I have a pretty decent video transmission from a color camera.

 

I couldn't believe I had anything at all without the baluns. I do notice in the sun I have a horizontal sweeping line that runs slowly from right to left in the image if you look closely.

 

I will assume a video balun will get rid of this.

 

Just wanted to share my experience.

Thanks

[survtech 0]

Twisted-pair does not work real well without the baluns. You may get a picture but as you discovered it may be noisy and have other problems. Balanced cable (twisted-pair) eliminates noise by having it cancel itself out in a balun or active receiver.

 

How this works is that the same noise will get to both conductors. At the balun or active receiver, the noise on the two conductors cancels out since they are connected + and -. Simple math; say x=noise, then (+x) + (-x) = 0.

 

Also, twisted-pair is 100 ohms and coax is 75 ohms. The baluns also match the impedance. Without them you will have an impedance mismatch which can cause signal loss and ghosting.

[perdueeye 0]

200ft is quite a short distance, the environment is clear, and the unbalance signal loss a little in transmission. So there is image on screen.