How to avoid Y Pb Pr signal ghosting over long approx 60m distance?

Answer 1

High frequency signals such as component video are susceptible to signal reflections over long distances. The reflected signal will appear as a ghost signal to the right of the original image.

Reflections can be eliminated by getting three things right:

The signal source must be a 75 ohm source. All professional equipment and most domestic equipment should provide this signal.

The cable must be 75 ohm co-ax cable. Low cost versions include URM70 and RG59 although better quality cables are available at a higher cost. For 60 metres, RG59 is likely to provide perfectly acceptable results. More expensive cable include the PSF range (a BBC standard used for analog and digital signals). PSF 1/3 will handle the length with ease. If the connectors needed are RCA, make sure the connectors are large enough to accept the cable. PSF is a large diameter cable.

The last item is the input at the destination. It must have a 75 ohm impedance.

If the source, the cable and the destination are all of the right type, the reflections will not be present. In domestic installations, a common problem is the use of screened audio cable rather than 75 ohm co-ax. If the cable is not a proper video cable, that is the first thing to replace. It is likely to make all the problems disappear but it is important to make sure the cables are terminated properly.

Less common is that the video source or the destination ports are not properly built to handle 75 ohm cable. Some domestic equipment isn't because it causes no problems for short connections. If that is the case, the solution is to obtain a line driver and a line receiver. There are many available but a reliable choice at a sensible price might be one of the Kramer range of drivers. The driver can be connected to the output with a short lead and the receiver connected to the input, also with a short length of lead. Do not install drivers or receivers until you know that the cable is right.