Hi, all.
As some of you may remember, I purchased two half slopers from W8AMZ
antennas about a year ago. One was a 160 meter antenna, and the other was
an 80-meter antenna.
Although it is a compromise antenna for sure, I have had at least some
success with the 160-meter antenna, in that I can keep my SWR's down below 2
to 1 on the lower half of 160, which is where I mainly like to operate
anyway.
However, I have not had as much luck with the 80-meter half sloper.
The radiating element of the antenna is roughly 30 feet long, and the other
half of the antenna is grounded to my 40-foot mast as a sort of
counterpoise. The center of the antenna is up about 30 feet. The antenna
is fed with about 30 feet of RG8X coax.
The resonant frequency of the antenna is around 3.900, but the sweet spot is
very narrow. My SWR's are up around 5.0 to 1 at both the top and bottom of
the band, with varying SWR's in between, ranging between 2.1 to 1, and 4 to
1.
Based on my experience out at the RV with my G5RV, I decided on a whim to
try something tonight. I pieced together about 100 feet of coax, and put it
as close to the transmitter as I could get it. When I did this, my SWR's
improved significantly. The were 3.0 to 1 at the top of the band, 4.1 to 1
at the bottom, and below 2.1 to one through much of the rest of the band.
The antenna tunes across the band with the TS590 auto-tuner.
My question here is: By doing what I have done here, am I just fooling
myself into thinking things are better when they really are not? I suspect
that anything I'm gaining by reducing the SWR is going to be lost in all the
extra coax I've now introduced into the system.
Am I correct with my reservations here, or should I not worry about things
as long as the TS590 auto-tuner can tune the antenna, thereby keeping the
radio happy?
For more info on the W8AMZ 80-meter half sloper, go to:
http://www.w8amz.com/W8AMZ_SLOPERS_Page.html#80HS
Thanks for everyone's patient elmering here.
73 from Tom Behler: KB8TYJ
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