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[TowerTalk] Was "43ft Vertical Feeding Question and Balun Type"

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Subject: [TowerTalk] Was "43ft Vertical Feeding Question and Balun Type"
From: "Michael Baker" <>
Date: Sun, 23 Nov 2008 09:40:44 -0700
List-post: <">>
Thanks to all for your input and to Alex F. Dolgosh K8EUR at DX Engineering
Customer Support for his follow up from the reflector.

Lots of information to absorb and I have still been modeling my butt off
with EZNEC 4+ using the DX Engineering tube sizes and lengths but playing
with the radial system.

One thing I noticed is that when you go to 80 meters the antenna looks like
about 10 ohms. Not a good thing to try to match up too.  Sort of have the
same problems as matching a mobile antenna. 

It occurred to me that if you put a trap (DON'T SHOOT THE MESSENGER HERE
PLEASE WHEN I SAY THAT DREDDED WORD!) of about 7 micro henrys and 175Pf and
then add a horizontal wire of about 14ft to make it resonate the match to
the feed line becomes a lot closer to normal at about 24 ohms.  SWR is 2:1
but much easier to match with more reasonable losses at the end of a run of

This might be a way to improve the match and performance of the antenna for
that band. 

I just wish someone made a full gallon rated, self contained and powered,
automatic remotely operated antenna tuner. Sort of like using a Z11Pro on
steroids! ;>)
BTW, last year I had my trusty 6BTV up in the yard with no radials and put
my Z11 with its self contained battery pack outside in a Ziploc bag at the
base of the antenna and ran 160 and 80 meters with an extra coil from an old
Mobile Master mobile whip on it and an extended whip.  It was sort of
resonant about 2.5Mhz but it took power via the tuner and worked. Not great
but I managed to screw around and work a few stations. Oh, I was using 5
watts from my IC-703. Best contact was Polynesia on 160. Too bad I lost my
electronic logs.  ;>(

I guess with time as short as it is I will make do with the 6BTV again this
year but I am putting down as many radials as I can (36 likely) and go for

See you all in the pile next weekend.

Michael Baker  K7DD


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