Thanks Mark for your feedback.
On 3 Feb 2006 18:47:29 -0800, "Mark" wrote:

yes the FET is better for AC coupled signals

make sure you don't leave the gate OPEN when it is off, it is VERY high
Z and will pick up 60 Hz hum, that may be what you are seeing...
connect the gate to the source (ground) when you want the FET off..

if the 75 Ohm video cable is not temrinated, thee WILL be peaks and
valleys in the frequency respsonse due to the relfections adding
constructivley and descructivley,,,thats why we need terminations....

an N ch JFET with the source at ground, the drain to 75 Ohms to the
signal, and you control the gate voltage + for on and 0 for off should
work well.

Mark