[Elecraft] Inverted-L (was OT: Vertical antenna)

[Don Wilhelm]

  Mel,

I personally would not consider elevated radials that are non-resonant - 
but then all of my antennas are resonant.

I could consider something "balanced", like a 43 foot vertical having 43 
foot elevated radials and being fed with parallel feedline to the 
location of the tuner.  I would equate that to a dipole having 43 foot 
elements on each side of the feedline, but oriented in a different 
fashion to take advantage of things like the low angle radiation of a 
vertical antenna.

I am not on the edge of salt water, so the great low angle "advantage" 
of a vertical is not available to me.  I recently bought a (used) GAP 
Titan DX antenna, and installed it - it pales in comparison to my modest 
height resonant dipoles, and I have made comparisons with DX stations as 
well as distant domestic stations - the horizontal dipoles always are 
better.  I was expecting better results for the vertical on DX, but 
failed to find it.  (anyone want to buy a GAP Titan DX for about half 
the price of a new one?).

73,
Don W3FPR



On 12/20/2010 6:56 PM, Mel Farrer wrote:
> It is a matter of loss or lack of it.  If you look at the takeoff patterns of a
> vertical antenna on a perfect ground and then with increasing loss, the pattern
> is modified to have increasing less energy on the horizon.  However, this is the
> loss factor, not necessarily due to lack of resonance.  As one removes the
> antenna network from direct ground, and substitutes radials, several things
> happen.  IF, and that is a big IF, the amount of coupling to ground is
> maintained with non resonant radials or resonant radials are used, eff and match
> will remain .  Example, a mag mount antenna or a ground plane vertical with
> three or four resonant radials works fine and any elevation.  Just a point of
> thought.
>
> Mel, K6KBE
>
>
>
>
>
>
> ________________________________
> From: Steve Ellington<n4lq at carolina.rr.com>
> To: Guy Olinger K2AV<olinger at bellsouth.net>; Vic K2VCO<vic at rakefet.com>
> Cc: elecraft at mailman.qth.net
> Sent: Mon, December 20, 2010 3:44:28 PM
> Subject: Re: [Elecraft] Inverted-L (was OT: Vertical antenna)
>
> Guy:
> Very interesting....
>
> Some of your comments were verified in a recent QST article.
>
> Mar 2010 - QST (Pg. 30)
>
> An Experimental Look at Ground Systems for HF Verticals
> The author experimented with resonant vs nonresonant radials on the ground
> and found performance improved when the radials were cut to electrical
> resonance vs just measuring them with a tape.
>
> Given this, it stands to reason that if the same radial field is used by a
> multiband vertical on a higher frequency, the high current point would be at
> some distance from the antenna's base thus reducing efficiency.
>
> Now here's the question....
> Folks assume ground radials to be (non resonant) but that isn't the case. So
> what would be the best solution for a multiband antenna with ground radials?
> Well if we follow this idea, we would need multiple 1/4 wavelength radials
> for each HF band for best performance.
>
> My inverted L is 50' up and 150' out. I use a separate elevated counterpoise
> for each band. I've found that a ground rod and some buried radials have
> virtually no effect. I just use them for lightning protection.
>
> Steve
> N4LQ
>
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