Gary-
When you say "spring maintenance," are these existing antennas that
exhibited 1:1 SWR at a previous time? If so, what changed?
Or are these new antennas you have just installed? In that case, since you
took these SWR readings at the antennas, they must look much better in your
shack at the other end of 350 feet of coax!
73,
Steve
N6SJ
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Gary
Smith
Sent: Monday, June 20, 2016 7:58 PM
To: towertalk@contesting.com
Subject: [TowerTalk] Help needed, antenna SWR
I did some spring maintenance on my antennas and need advice on how to get a
1.1 match.
I have a radial plate with somewhere around 50 130' radials. I have 5 wire
antennas attached to this and use an Ameritron remote coax switch to select
which antenna to use. There is a sloper for 160, INV-L for 80 and verticals
for 40, 30 and 20. 17 & 24M are obtained by selecting either the 160 or 80M
antennas. No tuner.
I took the Antenna analyzer down to the antennas today and found 80M is SWR
1.8, 40 is SWR 1.9, 30M is SWR 2.35 to give some values. The lowest SWR I
could get on 30M is 2.35 and the antenna is cut for the right length for
minimum SWR at 10.100 MHz. This gives me the lowest SWR on the bands.
I would like to get the SWR down as low as 1.1 at my desired frequencies If
I can do so, but I'm not sure of the best way to do this. I suspect
inductance from a coil at the individual feed points would work after I get
the to SWR dip the lowest at the desired frequency but if this is the
solution, what would be a good way to know do make such coils for each of
the antennas?
The antennas are 350 feet away, in the woods & onto a salt marsh and for me,
right now, walking is very difficult to do and I want to make as few trips
as possible.
Suggestions appreciated.
73,
Gary
KA1J
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