Hi All,
I'm looking to make a pair of adapters so I can transmit s-video and stereo
audio over CAT5, and I'm wondering if anyone has any circuit diagrams, or
links to similar projects
cheers,
Sounds challenging. CAT 5 cable has 4 pairs. I believe s-video has three
signals, and stereo audio has 2. So the obvious solution of using 1 pair
per signal won't work.
Would you consider sending audio over its own cable?
If so, you could probably send the S-video over three pairs in one cable,
and up to 4 channels of audio on the other cable.
Next is the impedance mismatch problem. Cat 5 cable has a differential
impedance of about 100 Ohms. Video wants to see 75 Ohms. You can
use either a transformer (assuming the DC component of the video singal
doesn't matter.. I'm not sure about this) , or a video op-amp buffer to
match the impedance for the video signal. At the receiving end, you
probably need to convert back to 75 Ohms, which means another buffer or
transformer. Or maybe you can just put a 25 Ohm resistor in series with
the 75 Ohm load.
For the audio, you might get away with just sending it over the cable
without any matching. Or you could use a high current buffer at the
sending end and terminate at the receiving end with 100 Ohms.
You may get some crosstalk on the audio channels.
Good luck.
regards,
Mac