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Re: Topband: Are stacked verticals feasible?

To: Anthony Scandurra <anthony.scandurra@gmail.com>
Subject: Re: Topband: Are stacked verticals feasible?
From: Mike Armstrong <armstrmj@aol.com>
Date: Fri, 6 Sep 2013 20:21:22 -0700
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Tony, Thanks...,. that is the one.  As I recall a very good book "from my 
youth."  It was one of the first antenna books that I remember reading in my 
early ham years...... I think its original publishing date was after I was 
first licensed (1960, when I was an ancient 8 years old... LOL).  But it 
couldn't have been too much later than that.  Still in production...... Well, 
that is a good sign :)

Mike AB7ZU

Kuhi no ka lima, hele no ka maka

On Sep 6, 2013, at 19:52, Anthony Scandurra <anthony.scandurra@gmail.com> wrote:

> Mike,
> 
> This is the book.
> 
> http://store.cq-amateur-radio.com/Detail.bok?no=26
> 
> 73, Tony K4QE
> 
> 
> On Fri, Sep 6, 2013 at 10:41 PM, Mike Armstrong <armstrmj@aol.com> wrote:
>> Carl and Charlie,
>> I am not sure it would even be close to practical or even doable, but I 
>> remember seeing an old book on verticals written by a prior Navy Captain, I 
>> believe.  He had a very interesting design for what WE would, today, call a 
>> collinear that was 3/4 wave length tall on 20 meters..... it was, in reality 
>> what looked like half of a double-zepp antenna in a vertical orientation. It 
>> intrigued me that it was like a half wave stacked on top of a 1/4 wave 
>> worked against ground (normal radial field). The interesting part was how he 
>> used a "skirt" around the "middle" quarter wavelength portion to produce the 
>> the in-phase relationship with the physically lower 1/4 wave.
>> 
>> You guys may already know the design I am talking about.  I saw that book a 
>> long time ago, like back in the late 60's I think..... maybe early 70's. I 
>> was considering trying to find the article or book whenI was looking for a 
>> better vertical for my winlink node on 20 meters..... the one I have been 
>> talking about.  However, I tried the 5/8ths first because I knew how to 
>> build one without having to possess any special instructions.  It was so 
>> successful, that I completely forgot about the "collinear."  On the other 
>> hand, this discussion reminded me of that book and how author "raved", a 
>> little anyway, over its performance.  I remember that the height of the 
>> finished antenna for 20 meters was something very close to 50 feet...... and 
>> that is not much taller than a 5/8ths..... maybe 7 or 8 feet taller.  So on 
>> 20 it is very doable and, supposedly, it has some reasonable gain for the 
>> effort.  I would like to find the book because it described a good way to 
>> make that all-importan
 t s
>>  kirt that got the phase correct between the upper half-wave and the lower 
>> quarter-wave sections.  Due to its relatively tall structure, it probably 
>> wouldn't even be "possible" to build one for 160..... at least not by most 
>> of us.  It would be interesting to see if it has the same "problem" that Tom 
>> was referring to for the 5/8ths..... "too low" radiation angle.  I know it 
>> isn't supposed to have that secondary lobe that a 5/8ths has...... So maybe 
>> it would be an improvement ..... IF it was even possible to build one.  That 
>> would be one tall structure on 160.... LOL LOL. Still, for someone needing 
>> an omni antenna with some gain on the higher HF bands, it might be a decent 
>> answer.  Never built one, so I really don't know if it really works or not.  
>> Although, as I said, that author was a Navy Captain whose job was designing 
>> some of the shipboard antenna systems, like the NORD and some other odd 
>> ducks.... Well, "odd" to those who don't have to build low loss, low band 
>> antennas
  on
>>   a floating "postage stamp."  I know, I know, you might have trouble 
>> thinking of something the size of an Aircraft Carrier being referred to as a 
>> floating postage stamp, but if you have spent any time at sea on a "big 
>> deck," you know exactly what I mean by that statement...... he he he he.  I 
>> really should remember his name, darn it..... with all the time I spent on 
>> ships at sea working with his designs, it is really sad (bad?) that I don't 
>> remember his name...... Paul "something?"  I'll find out..... lol
>> 
>> Mike AB7ZU
>> 
>> Kuhi no ka lima, hele no ka maka
>> 
>> On Sep 6, 2013, at 19:03, "Charlie Cunningham" 
>> <charlie-cunningham@nc.rr.com> wrote:
>> 
>> > Well, Carl
>> >
>> > You just proposed a total height of 3/4  wavelength, it seems. Do you have
>> > that much height?
>> >
>> > Charlie, K4OTV
>> >
>> > -----Original Message-----
>> > From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of ZR
>> > Sent: Friday, September 06, 2013 9:26 AM
>> > To: Shoppa, Tim; topband@contesting.com
>> > Subject: Re: Topband: Are stacked verticals feasible?
>> >
>> > Look at it as 2 ground planes with the lower feed point 1/4 wave above
>> > ground along with its elevated radials which should make it pretty much
>> > ground independent according to what has been published on here and
>> > elsewhere.
>> >
>> > The second ground plane would be identical with 1/4 wave spacing from the
>> > top of the lower antenna or a 1/2 wave between feed points.
>> >
>> > Then I would think that the ground conductivity at the reflection point
>> > would be the only concern as far as efficiency and gain??
>> >
>> > If installed as vertical dipoles then there would also have to be 
>> > additional
>> > spacing between them.
>> >
>> > I would think that at 6-12' spacing from the tower it would minimize
>> > interaction on 160 or 80?
>> >
>> > Does anyone on here have EZNEC and can plot this?
>> >
>> > Carl
>> > KM1H
>> >
>> >
>> >
>> > ----- Original Message -----
>> > From: "Shoppa, Tim" <tshoppa@wmata.com>
>> > To: "Carl" <km1h@jeremy.mv.com>; <topband@contesting.com>
>> > Sent: Thursday, September 05, 2013 10:30 PM
>> > Subject: Re: Topband: Are stacked verticals feasible?
>> >
>> >
>> >> Isn't this a "Vertical dipole"? Two quarter wave radiating elements? And
>> > tower behind it will be some kind of reflector/director depending on 
>> > height.
>> > The radials seem unimportant if thought of this way.
>> >>
>> >> Tim N3QE
>> >> ________________________________________
>> >> From: Topband [topband-bounces@contesting.com] on behalf of Carl
>> > [km1h@jeremy.mv.com]
>> >> Sent: Thursday, September 05, 2013 9:17 AM
>> >> To: topband
>> >> Subject: Topband: Are stacked verticals feasible?
>> >>
>> >> Assuming that sufficient tower height was available, guy wires are
>> > insulated
>> >> or broken up into short non-resonant sections. Tower face is 12 or 18".
>> >>
>> >> Start at 1/4 wave up with a 1/4 wave ground plane with radials sloping at
>> >> about 45 degrees. The vertical wire is 6-12' away from the tower face.
>> >>
>> >> Then a 1/4 wave (or 1/8) up install a duplicate.
>> >>
>> >> What does EZNEC say about this?
>> >>
>> >> With the different spacings?
>> >>
>> >> Effect of starting lower and how low before there are ground related
>> >> problems?
>> >>
>> >> Phasing with coax or a LC network?
>> >>
>> >> Switching in a delay line to tilt the lobe up a bit?
>> >>
>> >> Curiosity got the cat!
>> >>
>> >> Carl
>> >> KM1H
>> >>
>> >>
>> >>
>> >>
>> >> _________________
>> >> Topband Reflector
>> >> _________________
>> >> Topband Reflector
>> >>
>> >>
>> >> -----
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>> >
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