Hi to all.

Reading Mike's post reminded me of a wonderful little passive preselector
that I picked up at a hamfest for tightening up some receiver front ends
that weren't very tight.  In my case it was the Icom IC-R100, but I suspect
it is the same kind of challenge that Mike has found with the THF6A.  The
preselector that I found to be so helpful was the Grove Enterprises TUN-3
Receiver Preselector, and it was "heads and shoulders" above the Ten Tec
antenna tuner that I used on the HF rigs, when it came to tuning out
unwanted signals on the receiver.  It consisted of a series LC circuit that
used a 365 mFd variable capacitor of the type commonly found in AM radios,
and a inductor that was tapped for the various tuning ranges.  The
preselector covered 100 kHz to 30 MHz.  While the tuning was pretty broad
above 12 MHz, it was actually quite sharp in the medium wave and long wave
frequencies.  Even at shortwave frequencies, I could get enough Q out of it
to dramatically improve the performance of the Icom R-100 which was prone
to intermod and front end overload problems.  Even though the R100 has been
sold long ago, I hung onto that preselector, just in case I get another
receiver that is a little loose.  I wonder if something like that would
clean up the THF6A?

73, de Lou K2LKK



Louis Kim Kline
A.R.S. K2LKK
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