I have a strange problem. When I use a camera as a input source the device works just fine. However when I hook up my VCR to it the overlay displays okay a few seconds but quickly fades to the point that you can hardly see the overlay. Do you know how to fix this?
I think that this is because your VCR is outputing a voltage that is higher than it should be, so the 1V signal from the Video Experimenter is not high enough to be fully opaque. Try adding a resistor in parallel with the 330 ohm resistor or 1K resistor. For example, if you run another 330 ohm resistor in parallel with it, the effective resistance is 330/2 ohms. I think this will raise the voltage of the output signal and make the “white” more opaque. Try experimenting with different values of resistors in parallel with the 330 and or 1K resistors to reduce that resistance to the output. You won’t break anything and I think you will find a way to make the white more opaque relative to the underylying video signal.