Howdy all,
Well, about 2 months ago I went off and got married. Now with a second
person living in the house it's time to start cleaning up some of that RFI
stuff that never bothered me.
My wife's TV is in the living room just down the hall from the shack and
just about directly below the tri-bander on the roof. We have CATV.
I have wrapped Amidon FT-240-77s (the big cores, type 77 matl) around the
power cord and the coax (on the coax side I have about 30 turns of some thin
75 coax and I probably have about 12 turns on the power side). My problem
band is ten meters (20 and 15 don't seem to bother the TV with the fixes
I've implemented). I have been able to get nearly every bit of interference
out except just a little. On channels 2 and 6, there is still a very slight
picture distortion with or without an inline filter. That I think is
tolerable. However, it's odd why those two channels are a problem. Maybe
it's some ingress? Don't know. Also, on every channel there does appear to
be a very slight color change or very slight distortion of the picture when
I key. But while I would like to eliminate them, they are "tolerable."
The big problem is that I am getting a buzz on the speakers as I key the
radio. It occurs on all channels and with the coax disconnected as well. I
have gone inside, found the speaker wires and wrapped them around one of the
smaller Amidon torroids. I think I wrapped about 11 turns. Still get the
buzz. It almost sounds like a 60 Hz buzz so I am wondering if I need
another torroid on the power line.
The TV is an RCA model from 1990. I don't think the shielding is too good
since 100 Watts wiped out the TV without any RFI fixes.
My station consists of an FT-1000D, an Homebrew 4-1000A amplifier, and ICE
HF bandpass filter, a Heathkit antenna tuner and a Mosley TA-33. Power out
is 1500 Watts.
Can anyone give me any idea as to how to eliminate the hum? The 10 meter
contest is this weekend and I don't want to interfere with her watching TV.
73,
Jon
NA9D
-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)
Member: ARRL, AMSAT, DXCC, NRA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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