Topband: Hi-Pass filter for 160 to reject BC Band

[k8gg at voyager.net]

Fellow Topbanders:

Another Hi-Pass filter is shown in the 1986
ARRL Handbook on page 30-24.  It is also shown in other ARRL
Handbooks.  The original article was published in QST in Feb 1978 and
was written by W3NQN, Ed Weatherhold.

Charlie, W0CD, found he
could spread a coil or remove a turn to "customize" the
rejection for local stations.  Although we do not have an actual
filter-response curve, we were able to move F4 up to 1400 KHz to nul a
local broadcast station just over a mile from my QTH, which seemed to also
move the start of the attenuation closer to 1.8 MHz.  

This arrangement worked well for me with an AM 930 station running 1 KW
at night only 1/2 mile from my QTH whether I was using a beverage or
pennant receiving antenna that was receiving signals that had to pass by
the AM 930 station to get to my QTH.

YMMV

GL &
73 & HNY

George  K8GG