I do not have any problems with 10M on the C3, but I do have a shift on 15M
on C4XL's, which I believe is due to the proximity of the 15M element to
the 55G when the C4XL is mounted to mechanically balance it. Tuned by
themselves, the C4XL's were adjusted for lowest SWR (about 1.2 to 1) at
about 21.075 mHz. Up on the tower, they ended up with a minimum at about
21.300 or so. The reflected power is low enough for the amplifier to
tolerate on CW, and the pattern seems okay, so I haven't tried to retune
them. Also, I think the 15M elements are already set for maximum length
without adding some more tubing. Likewise, the 40M sections were tuned for
7020 and ended up about 7080 once installed on the tower. I have to reduce
power a little bit below 7010, but otherwise no big deal. 10 and 20 did
not change at all when installed on the tower. I will add spacers to my
list of possible future fixes. Thanks.
73 John N5CQ
-----Original Message-----
From: Michael Lamb [SMTP:n7ml@imt.net]
Sent: Monday, August 31, 1998 5:25 PM
To: towertalk@contesting.com
Subject: RE: [TowerTalk] Force 12 C3D 10 meter problem
----------
From: Hank Lonberg[SMTP:Hank.Lonberg@harrisgrp.com]
Sent: Monday, August 31, 1998 10:15 AM
To: towertalk@contesting.com; Dfmich@aol.com
Subject: Re: [TowerTalk] Force 12 C3D 10 meter problem
Just thought someone might be interested in what I discovered with my C3D
antennas
yesterday. I have had problems with my C3D stack on 10 meters since I
installed them
three years ago. They were all tuning about 27.5 MHz and the factory had
no answer for
me. We surmised that maybe the problem was the way I have them mounted
right against
my 55G tower. Until lately the band has not been all that good and so I
really didn't care
much about it, but now I wanted to finally get it straightened out.
SNIP
73/Mike, N7ML
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