FM Interference
 

Hey, I picked up a hallicrafters S-120A at a yard sale the other day,
hardly ever used, pretty good shape. I'm quite impressed with it compared
to my Zenith
D-7000 and Realistic DX-375 and other old crap radios around here. Only
complaint is the Ministry of Truth (CBC) has a 30,000 watt fm transmitter
that I can see from my window which causes some problems on the higher SW
freqs. Any one know of a filter I could build, or other solution.

Sorry about posting about radio. I'll try to bash a political viewpoint
next time.

Norm

A low pass fitler designed for ~30MHz ought to help.
Look up a low pass fitler desinged for ham transmitters.
Cehck oyour local public library for the ARRL Ham Handbook.
They have featured good designs before.
You may have to add some RFI control on the power cord as well.
Corecom makes some nice RFI IEC(PC power cord) style fitlers.
If the case isn't metal you might want to find some copper screen and
line the inside of the case to stop direct pickup.

Strong, close RF sources can be beat, but it requires some work

And don't feel too bad about an on topic post, it will be one of
very few today.

Terry

"NDeveau" wrote in message
...
[snip] Only
complaint is the Ministry of Truth (CBC) has a 30,000 watt fm transmitter
that I can see from my window which causes some problems on the higher SW
freqs. Any one know of a filter I could build, or other solution.

If you are using an external antenna with a co-axial downlead and the radio
is well-screened, Terry's suggestion of an in-line low-pass filter will
work. A cheaper solution is a transmission line stub notch filter cut for
the offending frequency. Insert a tee connector in the co-ax line. Add a
stub of co-ax off the tee, open-circuited at the far end, about a foot long.
Trim about a 1/4" at a time until you reach minimum interference. If you go
too far, make another one!.

Tom