Cable BNC correct

[luckyo]

Hi

I have an old PAL CCIR signal which I am connecting via BNC to a AJA IO HD.
Since I experience a lot of ghosting in the captured video, I was wondering if this could be due to the cables or the connection.
Is there anything to pay special attention to, when cabling ?
How should I correctly ground cables ?
What length/Ohm value is ideal when I want the best result ?

Thank you !

[pandy]

Most video equipment (all?) use 75 ohm impedance, then all connections shall be made with 75 ohm cable and plugs, my advice to grounding loop (to avoid grounding loop) can be implemented in very easy way - just provide power supply from one point - ie your PC, video source and capture equipment must be connected to 3 line (with grounding wire) power network - i believe that nowadays this is standard in Germany and You use Schuko plugs and receptacles - you can use power strip (Mehrfachsteckdose) to provide correct connection and one power source - this should reduce potential issues with power network. Perhaps there is need to set termination on AJA input (quite commonly video equipment particularly professional can have optional termination that can be turned ON/OFF if more than one device is connected to cable.

And at the end check AJA configuration (i mean that correct video mode is selected).

[luckyo]

Thank you very much, very helpful.
Ok so the 75 Ohm part is exactly what I did, so this can't be the problem.
What exactly does set termination mean ?

I found this here in the AJA Manual:

"The Ref Output connector is not a loop-through—the input is terminated
internally and buffered to the output. Both input and output Ref connections are
75 ohm."

http://www.aja.com/pdf/support/AJA_IoHD_manual.pdf

Thanks again.

[pandy]

http://en.wikipedia.org/wiki/Electrical_termination

From AJA Manual info is quite simple - there is no external or switchable termination thus this is not a problem.

If this is grayscale signal then perhaps You can use only Y (from YPbPr or from S-Video) connection to source, if source can output S-Video or YPbPr then it will provide highest possible quality - remains unused inputs ie PbPr or C in S-Video can be closed by 75 ohm terminators. (https://encrypted.google.com/search?q=75+ohm+terminator+bnc&hl=en&safe=off&prmd=imvns&...=univ&tbm=shop).

It will be good to turn ON "color killer" on your source if this is possible (this can improve quality but only for composite and sometimes(very rare case) for S-Video)

http://en.wikipedia.org/wiki/Color_killer