[TowerTalk] Wire antenna?

[K9MA]

I've long been a fan of the EFHW for portable operation, but I've always 
used a tuner. There seems to be a lot of aversion to tuners. If you can 
get over that, many possibilities open up. A simple L-network will match 
the EFHW. (Though not the ones built into radios.)

The EFHW is easily modeled with EZNEC, etc., and I think the results are 
quite accurate. Beware, however, that antennas like the EFHW-8010 are 
multiples of a half wave on all but the lowest band, and their pattern 
will behave accordingly. On the lowest band, it's much like an inverted 
V, and has the advantage that, even though the feedpoint is near the 
ground, the maximum current is at the apex, where it radiates most 
effectively. I've used a 40 meter EFHW on 40 and 20 with good results 
for portable operation.

Another wire antenna I've had good success with over the years is a 100 
foot wire center fed with 300 Ohm window line. Like the EFHW, it has the 
advantage of not needing a good ground or counterpoise, so it's a good 
choice for an apartment, etc. not on the ground floor.  It requires, 
however, a truly balanced tuner, not one with a balun transformer at the 
output. I used a homebrew link-coupled tuner I built over 50 years ago. 
There is one MFJ tuner that's truly balanced, but I haven't used it.

73,
Scott K9MA

On 7/1/2019 10:18, john at kk9a.com wrote:
> It needs no tuner or counterpoise and it has great eham reviews!  How 
> does this work?
>
> John KK9A
>
>
>
> David Gilbert xdavid at cis-broadband.com
>
> The EFHW-8010 gets rave reviews, but I'm fundamentally suspicious of any
> antenna that covers that wide a range without tuning.  There have to be
> losses somewhere to get that.
>
> Those same reviews also claim similar results for installations 6 feet
> off the ground versus 60 feet.  That also doesn't make sense given the
> effect that ground typically has on the feedpoint of a horizontally
> polarized antenna without a lot of loss.
>
> I couldn't find anyone who had done a real time A vs. B comparison
> against, for example, a center fed dipole at 40 feet on 20 meters. I'm
> not saying that the EFHW-8010 isn't a practical single antenna for a
> given set of constraints, but I'd bet a lot of money that you could do
> better with a collection of other properly chosen wire antennas if you
> have the space (presumably you do if you can put up a 130' long
> EFHW-8010) and some decent trees.
>
> And if your ground conductivity isn't too bad, I'd even consider an
> Inverted-L or two with VOR-type counterpoises before I'd rely on
> something that physically shouldn't work without a lot of loss ...
> especially if the distance from the antenna to the shack is short enough
> that you could use a tuner for operation on multiple bands without a lot
> of feedline loss due to SWR.
>
> My two cents worth ...
>
> 73,
> Dave   AB7E
>
>
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-- 
Scott  K9MA

k9ma at sdellington.us