Hi Will,
From my personal experience, my inverted L works fairly well. I have a
US Towers TX-455. At the top of the tower I put a "yardarm" out to the
side that has a pulley on it to raise and lower my antenna. With the
160M wire going from about 4 feet from the bottom of the tower up to the
pulley on the yardarm, then out to a tree horizontally, it seems to do a
fair job.
I have 40 radials on top of some pretty rocky soil. I used a Palstar
ZM-30 antenna analyzer to cut the antenna to the low end of the band
where it resonates at 1.835 MHz. The SWR at that point is 1:1. I
noticed that by moving the bottom of the wire toward/away from the base
of the tower, I was able to get a better match at certain distances.
As for interaction - I have a SteppIR 4L with the 30/40 add on on top of
the tower. I can retract the elements so that there is no interaction
from the yagi. In practice, I see little interaction even when the
elements are left extended.
I'm not a big 160M operator, and only have 23 countries from less than
aggressive searching for them. Of note - and it may be largely due to
the excellent "ears" of VP6DX operators, I worked them on 160 CW and
SSB, each time with one call, and running barefoot 100 watts.
With your extra vertical capability, you should do well. Good luck on
your project!
73
-
Joe Hannigan - WDØM
Pagosa Springs, CO
http://www.WD0M.com
http://www.pagosarocks.com
http://www.quiltqueen.net
----- Original Message -----
> From: <aa4nc@aol.com>
> To: <towertalk@contesting.com>
> Sent: Saturday, February 23, 2008 5:00 PM
> Subject: [TowerTalk] inverted L tower mounting
>
>
>
>> I want to upgrade antennas for 160m from my current inverted vee @ 115'.
>> I'd like to put up an inverted L to get some vertical plus horizontal
>> polarization for DX and domestic contesting. My situation is that the only
>> two supports that I have are towers. Most everything that I've read says
>> this doesn't work well, however I've seen some guys do it.
>>
>> I'd be interested from hearing from anyone who has had good luck mounting
>> a 160m inverted L on standoffs from a grounded steel tower. The guys are
>> broken up with insulators and I have 2 towers to choose from - 90' with
>> 10/15m yagis and 130' with 20/40m yagis. The towers are 110' feet apart.
>>
>> 73 / Tnx,
>>
>> Will AA4NC
-
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