[ppppenguin]

Just because a video source claims to be 75R, there's no reason to believe it unless it quotes the return loss** figures. For example 40dB return loss means it will reflect 1% of the signal. Return loss varies with frequency, usually worse at higher frequencies. Traditionally, analogue broadcast grade kit aims for a return loss of better than 40dB up to 5MHz for both inputs and outputs. For consumer grade kit it's variable. Outputs can be very poor, sometimes down to 10dB or less. Inputs are usually better.

I have measured the return loss of many video inputs and outputs over the years. The results have been very varied. You can't do this without special equipment (return loss bridge or vector network analyser) which I have, as a design engineer. I have designed a lot of equipment with video inputs and outputs.

I too have made many of my own 75R terminations with a BNC plug and a resistor.

**The radio frequency people use VSWR. It's the same thing expressed in a different way that's more meaningful to them.