Topband: progress with the antenna adventures

Bill Cromwell wrcromwell at gmail.com
Mon Apr 9 12:22:00 PDT 2012


Hi,

I whizzed up an L network to put on my wire after the Murch disaster.
Instead of making something more elaborate using my roller inductor, I
used a tapped coil (with alligator clips) and a large value dual cap
from a broadcast receiver (yes - using low power). I will need either
more inductance or more capacitance. Adding a switched in cap seems to
be the better idea. I run out cap just when the swr starts it's
nosedive.  80, 40, 30, and 20 have clearly defined sweet spots and a few
on-air tests are encouraging. The RBN is down at the moment. When it
comes back up I'll make use of it to help gage results, too. When I get
a handle on the parameters for my network I'll get around to a nicer
project with that roller inductor and some *big* caps in a big metal
box.

That Murch needs a lot of work to ever work with my kind of antennas.
Maybe I should offer it in trade for something more useful to me. Is
anybody here interested in a Murch 2000B? The paint has started peeling
from parts of the cabinet as Murch did not use any primer at all (easy
to remedy). I suppose it would be fine as-is for somebody with coax fed
antennas that are 50 ohms resistive. It can handle the legal limit and
is supposed to cover 160 meters. It even tried to tune my end fed wire
but with a T network it was "no joy". I'll try using the Murch for some
fishing bait before I make radical mods to convert it to an L.

73,

Bill  KU8H



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