Interesting information Jim. If I were in the market for a tribander I
would definitely buy the K7LXC report. One potential problem with
interlaced beans is that there appears to be little room for side mounting
them on a tower. I also wonder what happens when they are used in a windy
environment and the closely spaced element move around.
John KK9A
[TowerTalk] Mosley Antenna Question
from [Jim Thomson] [Permanent Link][Original]
To: <towertalk@contesting.com>
Subject: [TowerTalk] Mosley Antenna Question
From: "Jim Thomson" <jim.thom@telus.net>
Date: Thu, 26 Feb 2015 07:32:51 -0800
List-post:
73, Jim K9YC
## heres the latest from F12. 20-15-10 all on barely a 10 ft boom.
http://www.force12inc.com/products/xr3-compact-6-element-20m-15m-10m-multi-mono-contest-yagi.html
## heres the latest and greatest..with booms shrunk by 30%. The old C3,
xr5
etc line up has been upgraded to the newer format.
http://www.force12inc.com/categories/beam-antennas/all-new-xr-series-multi-mono-hf-yagi-beams.html?sort=pricedesc
## BTW, I see n6bt wrote an entire section on trapped yagis in his book,
array of light. . Turns out I was correct. By encasing the coils with AL
tube, the coil Q drops down to just 20-30.
feed Z rises to close to 50 ohms..cuz of the excessive losses by the high esr
of the low q coils. He mentioned that one maker of trapped verticals
used a
ceramic core to wind the coils on,
so it would handle the extreme temps.
## He also mentioned about HF yagis using the T match...and the 200:50 ohm
coax balun. Several of them had the main lobe canted off to one side by 20
degs ! The fix was to replace the T
match with a conventional hairpin setup. He did not mention the brand, but I
suspect it was telrex... the only co I know of that used a T match. Why the
lobe ended up skewed 20 degs to one
side is beyond me. He mentions fixing several of them.
Jim VE7RF
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