Newsgroups: sci.electronics.misc
Subject: Re: Send composite video thru 300 feet twisted pair ?`
References: <[email protected]>
R Smith  writes:

> I desire to transmit a composite video signal thru 1 pair of a 
> 4 pair lan cable which is currently unused, although ac power 
> will travel to the camera on a second pair - about 1/4 amp at 
> 18 volts, it will be converted to 12 volt regulated at the camera. 
> 
> The video voltage level varies from -.5 to 2 volts. Probably 
> some sort of buffer amp is needed and it will be good to maintain 
> these dc voltage values.
> 
> If needed a split power source could be made available at the
> camera ( say, -12 & +12 ).
> 
> Anyone have suggestions ?

First take a look at "http://www.epanorama.net/wire_av.html" section at
http://www.epanorama.net/wire_av.html to get the idea how
to run video over twisted pair wiring. Then go to 
http://www.epanorama.net/videochips.html#distribution
to find circuit diagrams for this application.

For 300 feet transmission you can use only passive
video baluns, theyu should work well up to those
distances. Maybe not need to go any active circuits
for this application (those will work as well, propably better).


-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/