The advantage of using insulated elements mounted above/below the boom
is that one does not need to correct for the boom. There is no need to
adjust the elements for shortening due to passing through the boom as
is the case with the Hy-Gain "clamshells" or other mounting designs
that use aluminum plate and conductive (U-Bolt/saddle) mounting. Even
1/8" thick PVC or fiberglass tubing is enough to eliminate nearly all
"boom effect" at HF.
73,
... Joe, W4TV
On 2014-08-05 1:40 PM, Hans Hammarquist via TowerTalk wrote:
Well Dan,
I just received a TX38 from Cycle24. All the elements are insulated from the
bom. I don't know if that's for convenience but the elements are clamped to the
bom with plastic/hard rubber cleats. I have no problems with the engineering of
it but it starts me wondering ...
Hans
-----Original Message-----
From: Dan Cisson <n4gnr@windstream.net>
To: Hans Hammarquist <hanslg@aol.com>
Sent: Tue, Aug 5, 2014 12:53 pm
Subject: Re: [TowerTalk] Insulated elements, Yes - No?
Hans,, about all driven elements are insulated from the boom,,, and I have
NEVER seen the other elements insulated from the boom,,, they are always
grounded to the boom(not insulated)...Dan N4GNR
p.s. look at some of the commercial antennas like HyGain and M2,, look at
download manuals for those antennas
-----Original Message-----
From: Hans Hammarquist via TowerTalk
Sent: Tuesday, August 5, 2014 12:32 PM
To: towertalk@contesting.com
Subject: [TowerTalk] Insulated elements, Yes - No?
When I, (too many years ago) read building instructions for yagi antennas it
was claimed that it didn't make a difference if the non driven element was
electrically to the bom or not. Now I see that the element are insulated
from the bom.
What is the right thing to do? (I hope NOT to start a long discussion). Is
it the same thin with the driven element if I use a gamma match?
Best 73 de,
Hans - N2JFS
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