[Elecraft] 43' Vertical and the K2 tuner

[dyarnes]

Paul and All,

This is very interesting!  Thanks for bringing that article by VK1OD to our
attention.

I think I agree with you about trap losses.  I have used a Cushcraft R7, and
now an R8, for years with surprisingly good results.  What appealed to me
about both of these models is that they emulate a 1/2 wave antenna, thus
making radials more or less unnecessary.  These antennas only cover 40 and
up however.

What now intrigues me about the 43 ft. antenna is connected to some comments
made to me by Jim Duffey, KK6MC ("Dr. Megacycle") when he visited here some
time ago.  I think most of you are familiar with Jim, and respect (as I do)
his technical expertise.  Anyway, Jim suggested that I might be even better
off with a 22 ft. vertical on my roof, with as many radials as I could
reasonably lay out. He said I should also use a remote tuner and balanced
feedline.  Jim felt it would perform adequately on 40 meters, and better as
you go up.  I believe he said the "magic" about 22 feet was to try and keep
the radiation angle from getting too high on the higher bands.

So, now I'm wondering if a 43 ft. antenna would bring 80 meters, and
apparently 160 meters, into play under more or less the same concept that
Jim was espousing.  He didn't really mention that the 22 ft. version might
get you on 80, so maybe not, but the mathematical relationship sure has me
wondering.  Probably I'm extrapolating his comments incorrectly.

I think Jim does monitor this reflector, so maybe he will jump in and make
some comments.  I will probably pass that article to him though, and see if
I can prod him for some insight.

By the way, I'm guessing that if you could roof mount, or otherwise elevate
the 43 foot version, you might not have to worry quite so much about having
so many radials.

Anyway, this motivates me to do a little digging!

Dave W7AQK


----- Original Message ----- 
From: "Paul Christensen" <w9ac at arrl.net>
To: "Steve Ellington" <n4lq at carolina.rr.com>; <Elecraft at mailman.qth.net>
Sent: Sunday, March 15, 2009 7:07 AM
Subject: Re: [Elecraft] 43' Vertical and the K2 tuner


>> The 43' vertical is recent fad and it makes no sense at all. Virtually
>> any trapped multiband vertical should easily outperform it.
>
> Steve,
>
> I thought the same until I read this:
>
> http://vk1od.net/antenna/multibandunloadedvertical/
>
> According to the author, the so-called "magic" of the 43-foot length is
> that
> radiation resistance remains quite high across the HF spectrum and thus,
> system losses are minimized.  Compared to a 33-foot vertical, system
> losses
> are much lower across the spectrum.
>
> But to your point, a trapped multi-band vertical can offer similar
> performance.  Personally, I think the negativity associated with trap loss
> in multi-band antennas is grossly overblown.  Other systematic losses mask
> what little loss exists in most trapped antenna designs.
>
> Anyway, not sure how valid all this data really is, but the data presented
> is interesting
>
> Paul, W9AC
>
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