Thread: Preselectors
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Old April 28th 06, 12:43 AM posted to rec.radio.shortwave
Jim Hackett
 
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Default Preselectors

Wow. I'm not sure what you said Dale but even with your filter AND an
additional 20-40 dB of attenuation, it can still be heard throughout the
shortwave spectrum (on a bad day)



"Dale Parfitt" wrote in message
news:MD64g.8428$BO2.7464@trnddc02...

"Jim Hackett" wrote in message
m...
Well, I'm using RG-58 cable with connectors made for RG-8 soldered on

the
ends. Probably not the cleanest setup. Most radios aren't grounded.

I
don't notice any difference on the ones that are. This station comes in
on
just about everything that has an amplifier in it and probably a few
things
that don't! Sometimes it is terrible, other times it's not bad. 99.9%

of
the time after dark when they cut their power back to, I believe, 5 kw,
it's
not a problem at all.

If I worked nights, I'd be looking for a new hobby...

The problem in a case like this is, or could be, that w/o a good RF ground
at the filter, the 50KW signal can "blow by" the filter in common mode on
the exterior of the shield.
The other problem of them being legal, but still strong enough to hear

their
harmonics sounds as though is is still a possibility also.
Does your RX have a built in attenuator? Note how much the fundamental
signal is reduced when you switch in the attenuator. If this is IM, the IM
priducts should be reduced by more than the fundamental.

Dale W4OP