[TowerTalk] 80/160 meter antennas

[William L. Bischoff]

I've enjoyed the recently posted comments on 80/160 meter antennas.  Through
the years I've by choice continued to live in a modest home on an average
residential plot in a relatively high density neighborhood.  In that
environment, putting in place effective low band antennas is always a
problem.  For 80 I use a half-sloper hanging from the top of my 72' Rohn 45G
tower.  It is fed at the top.  It works well for a simple wire antenna.  My
country total on 80 is just shy of 300 with most major expeditions from the
last 15 years or so in the log. Having said that, I hasten to point out that
the effectiveness of this antenna has varied through the years depending on
what has been on the tower above it.  When my sole beam antenna was an old
cushcraft ATB34, the sloper was impossible to tune and worked miserably.
When I added a 2 element Hy-gain 40 meter beam 12 feet above the tribander,
the sloper came to life with low SWR, great bandwidth, and excellent overall
performance.  Later I replaced the ATB34 with a KT34XA and the aging
decrepid Hy-gain 40 with a 2 element 402CD from Cushcraft.  The sloper
continued to be an excellent performer.  Recently the stock 402CD fell apart
and I replaced it with an XM240. As a result, the performance of the sloper
has been severely degraded.  I'm sure having the 40 meter reflector
insulated from the boom is the problem, but I have to wait until our winter
weather breaks to address the problem. The saga will continue to develop
this summer because my C31XR is assembled and ready to put up in place of
the KT34XA.  Any guesses as to the fate of the sloper?

	On 160 I use an inverted check mark.  The apex is at 70 feet.  The radiator
is made out of 129 feet of 450 ohm KW ladder line shorted at one end.  On
the opposite end, one conductor is grounded while the other is fed directly
with 9913 coax.  I use four radials elevated about 12-15 feet off the
ground.  They meander through the trees that line my lot.  Certainly nothing
fancy.  The antenna is resonant at 1830 or so and gives me about 100khz
bandwidth.  This simple antenna is far better than any of the many loaded
slopers, inverted vees, and loaded verticals with ground level radials I
have ever used.  Further, it vastly outplays locals using Gap Verticals.  I
don't compete with the big guns on 160 but DXCC was a snap.  Last week there
were a couple of good openings and in the course of three evenings I worked
27 countries on that band.

Cheers, Bill, N8BR

Bill, N8BR


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