Lots of interesting topband antenna ideas. Not too much room here either, so
using the EWE rx antennas. Have three, broadside configuration 160' spacing.
Each antenna is 44' long, 10' high, with 1300 ohm resistors. One idea that
may be different is use of printed circuit boards at each antenna post to
switch directions, so there are 6 directions. Each board has a relay,
transformer and resistor to swap directions. DC control is thru the feedline
coax. Other relays are used to select one of the three antennas so that only
one long feedline is needed (about 300').
These are located in a field with lots of aluminum irrigation pipes, 50' for a
30m lazy-v, 70' for a 40m lazy-v, and two 90' pipes - those can be used as a
single omni vertical, or a 2 element endfire phased array for ZL or Europe. I
can also receive on the 160m tx antennas. Some EWE's work better than others
- maybe all the nearby aluminum or lots of trees nearby upset some of them.
The one for JA gives several s units of f/b. The one for ZL is ok, but the 2
element tx array is better. Use preamps to set level same as tx antenna.
Pertinent to all of this is the noise problem. Recently the powerline noise is
20 db over s9 when detected with AM, wide filters and no noise blanker (TS850).
With CW, two 250 hz filters and the noise blanker the noise is about s1.
However any reasonable USA signal in the band modulates the noise blanker with
the powerline noise and blots out most dx signals. Thus the MFJ1026.
Previously couldnt get it to work but in desperation went back to it. The
solution was to rewire my rx antenna control box to use the 90' tx antenna as
the noise or sense antenna, and the EWE's for rx. This sure helps. We had a
fox hunt for noise and think we have found the mother lode - now to get it
fixed!
73 Bob W7LR Montana
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