I just read the Joel Hallas, W1ZR article - "The 43 foot vertical monopole
- What's the magic?". It was very interesting! The coax losses are worse
than I imagined, up to 8dB though 100 feet of RG-213, and as my model
showed the radiation is very high above 20m. Certainly a relay to
electrically shorten the antenna would help 15m and 10m.
John KK9A
---------- Forwarded message ----------
From: <ve4xt@mymts.net>
Date: Sun, Apr 6, 2014 at 9:31 PM
Subject: Re: [TowerTalk] Hustler 6-BTV installation
To: "john@kk9a.com" <john@kk9a.com>
Cc: "towertalk@contesting.com" <towertalk@contesting.com>
Joel Hallas did a fine piece on 43 foot verticals a while back and agreed
with concerns about performance above 20m.
I wrote him and pondered the question about some form of automatic band
switching for higher bands, such as traps or stubs. We agreed it would be
worthy to model, but alas, I have as much experience with modeling as I do
with collecting lunar rocks.
Be cool if someone were to pick up that train of thought and run with it.
73, Kelly
ve4xt
Sent from my iPhone
> On Apr 6, 2014, at 13:07, john@kk9a.com wrote:
>
> I am not sure what his reasons are for changing antennas, however I have
> modeled a 43' vertical and found it be a horrible performer on some bands,
> especially 10m. Also it seems like it would be a pain to have to use a
> tuner and if the tuner is not at the antenna base you also have added coax
> losses.
>
> John KK9A
>
>
> To: TowerTalk@contesting.com
> Subject: Re: [TowerTalk] Hustler 6-BTV installation
> From: Matthew King <mrk.twg@gmail.com>
> Date: Fri, 4 Apr 2014 20:22:02 -0400
>
> Hi, Phil - I found on my installation of a 6-BTV that trap tuning was
> necessary to get the best tuning over my 45 radial field.
>
> I used a bulkhead for some time until I installed a DX Engineering choke
in
> an effort to knock out some RF in the shack. I've come to the conclusion
> that I'm just at the edge of the near field since the choke made little
> difference on 10m. Point being, I guess it's really up to you and your
> particular installation as to install the beads or not. It cannot hurt
> from my somewhat limited understanding, and may very well help.
>
> Might I ask why you've decided to switch to a shorter, trapped vertical
> rather than the 43' vertical? Also, did you have a tuner at the base of
> the 43' antenna?
>
> Take care,
>
> Matt King
> KK4CPS
>
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>
>
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