On Sun, 07 Nov 2004 16:47:18 GMT, GeorgeF
wrote:

Tom wrote:
The most likely cuase is that your receiver front-end is broad enough
to pass the TV2 signal through the RF amplifier, and modulate everything
else being received.

It's difficult to get a low-pass or high-pass filter will a sharp enough
cut-off to do much good. Better solutions are to build a notch filter for
the TV2 video carrier at 55.25 MHz (using a T-connector and a length
of coax trimmed to length, or to buy or build a passband filter for
50-52 MHz.

I had this problem with channel 11 and a 220 MHz receiver, and ended
up building a bandpass filter with a pair of coupled LC tanks, tapped at
50 ohms. Totally eliminated the TV cross-modulation problems.



1) Where can one buy a passband filter for 50-52MHz?

Try http://www.dci.ca/ they make passband filters for six meters, tho'
they're a little pricey.

Bob
k5qwg



2) When talking about coax trimmed to length, are you talking about a
coax stub? Such as cut to 1/4 wavelength of the offending freq? If so
would be ends be shorted or let open? never worked with stubs yet....

TNX
George