John,
On the high SWR on 20m, if you mean the one written up in the May issue of
QST, then I know it quite well. That's almost twice its normal SWR, so as
you suspect, there must be something metal affecting it. All I can think of
to do is to try to rotate the antenna as far as you can in either direction,
even if it means bending just one of the legs. That might reduce the
coupling to the metal object.
Out of curiosity, have you used it on 20m anyway with an antenna tuner.
If so, how does it work there?
73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of John Rippey
Sent: Saturday, October 15, 2016 7:16 AM
To: tentec@contesting.com
Subject: [TenTec] Retirement & my OMNI VI--follow-up
In my initial post, I should have mentioned that I have had an attic antenna
(It's an OCF-40 from "My Antennas," that was written up in QST
recently) installed for my own apartment, thanks to the cooperation of the
management, The antenna, as QST found, yields spectacular low SWR results on
40, 15, and 10 meters. On 20, though, its minimum SWR is a little high,
about 3.4:1. Luckily, there's virtually no external noise from appliances,
etc. Don't know why.
My Yaesus and Icoms struggle/fail with the 20 meter SWR using their internal
tuners, while my Jupiter's built-in antenna tuner handles it with no
problem. Ditto a TS-990. (I have some dozen transceivers accumulated over
many years, and other than the OMNI VI that I'm reserving for the club, I've
got to sell all but one or two of the rest. What a chore! Given the SWR at
my place, the Jupiter is a certain keeper and perhaps the 990 as well,
because I like the idea of 200 watts output even though the rig overall does
not float my boat.
Of course, an antenna for the club will be located in a separate building;
there's no telling what the results will be. It's a crapshoot. (I don't
think the management would go for a vertical.)
I'm thinking of having a professional installer climb up into the attic and
see if he can figure out why my antenna's SWR is higher on 20 than the other
bands--maybe its aluminum ducts, or whatever.
Yes, I meant "finals" not "front end." And thanks to all for the helpful
comments. This is a great reflector.
73,
John, W3ULS
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