I have a 50 KW station on 1530, eight miles north of me. They have a six
element in-line array aimed south at Mexico... and me. They tore up every
rig I've had in the shack until I went to a K3. We have two K3s and have no
problem on either of them with BCB other than weak birdies on 1820 and a few
other multiples of ten on 160 and 80. Rigs like the IC7000, and the FT857,
a TS850s and others have hash from that station across the whole HF range.
Even the TenTec Omni 6+ was plagued with junk everywhere.
Many years ago I borrowed a commercial sharp-knee hi-pass filter from
AA1K. I forget who made it but you could ask Jon. It may have been a NQN unit.
The filter was made to take the power output of a 150 watt rig. That did
the job for most all rigs. I duplicated the filter and made a couple of them
for use in this environment. I tweaked the toroid coil spacing and parts
positions until there was a cliff starting about 1790 and the transmit loss
was minute across 1.8 to 30 mHz. I built in my own sharp-knee filter in the
Omni 6+ and added a "suck-out" filter tuned to 1530. That fixed the TenTec.
In more recent times, The problem became critical when I installed the
HI-Z four element receiving array. Those "Plus" amps at the base of each
element were sitting ducks for all that broadcast RF. The birdies were 20 over
9
and the sidebands covered 12 kHz! Lee, K7TJR at HI-Z made up four matched
input traps for the amps and that brought down the problem to barely a
nuisance. I won't miss any contacts because of it.
We don't use any internal or external filters on the K3s and I'm surprised
that you are having trouble with yours. There has to be an answer to
explain that. The BCB RF is so strong here that our land line was always
providing the programming from KGBT. BTW, it's a 24 hour talk radio station in
spanish. We went to all cell fones a few years ago.
CU on Topband, 73, Barry, W9UCW
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