At 06:20 PM 5/5/98 +0100, you wrote:
>Hi and thanks for reading this.
> I have a problem with computer noies on the low bands her in just
> certain
>portions of the band.I am running a p100 here and it real bad on 40
>meters.It peeks at every 25 kz of the band.Is ther anyway to stop this
>besides turning the computer off?Thanks again Mike K5QF
>
>
Sounds like it may be coming from the monitor - 25 khz is probably your
sweep frequency. But I think the following will work, no matter where it is
coming from:
1). See if the interference is coming in via the antenna terminal by
disconnecting the antenna from the rig and shielding the antenna terminal.
That probably will knock the interference down to a extremely low level if
the radio is well-shielded.
2) If above works, then use a highly-shielded coax to bring in the signals
from the antenna. I use 9913 all the way from the rig to an outside antenna
switching box about 75 feet away from the computer. Of course, you want to
have your antennas located _very_ far away from the computer!
3) If you have other devices in the line (amp, antenna tuner, external SWR
monitor, etc), you will need to check them as per step (1) above. They
probably are not as well-shielded as the rig.
In my installation, I found a (highly-rated, commercially manufactured)
antenna tuner so poorly shielded that it was the major source of leakage
from the computer stuff. It would allow all the computer hash to enter my
feedline prior to the transceiver. Dumping that tuner and using the 9913
coax has reduced my hash to where I just am not aware of it anymore. My
antennas are more than a hundred feet away from my computer.
Jerry W4UK
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