I have the book. It is among the first antenna books I bought in 78 when I was
first starting in this hobby.
The book is The Amateur Radio Vertical Antenna Handbook by Capt. Paul H. Lee,
USN retired N6PL SK.
I built one of the 1/2 over 1/4 wave that you gentlemen are talking about for
20m and it worked very well indeed. the sleeve I used was a cage of 8 wires for
the middle 1/4 wave section which also gave the phase shift needed. It is not
perfect because the sleeve diameter prevents a perfect shift, but a happy
medium is possible and it will work.
73 es DX Pat H. Armstrong KF5YZ
PS I have a son named Mike
---- Mike Armstrong <armstrmj@aol.com> wrote:
> Hey...... IF the tower is tall enough for that duty (3/4 wave tall), then you
> could put that "skirt" on the "middle" 1/4 wave, as it were, and you got
> 'er...... Could he be that lucky? I have to admit, other than right this
> second, I hadn't ever considered that as a possibility. It "should" work so
> long as the height is close to correct and whatever is mounted to the top,of
> the tower doesn't make the structure look too,much larger than it should look
> for resonance.
>
> HMMMMMMMM
>
> Mike AB7ZU
>
> Kuhi no ka lima, hele no ka maka
>
> On Sep 6, 2013, at 19:58, "Charlie Cunningham" <charlie-cunningham@nc.rr.com>
> wrote:
>
> > Hi, Mike
> >
> > I remember the guy that you are referring to, but it's been so many years
> > that I don't remember his last name tither. He published a book via either
> > ARRL or CQ mag.
> >
> > A collinear 1/2 wave over a 1/4 wave GP has certainly been done and used
> > commercially at VHF. The "skirt" can also be replaced with a shorted 1/4
> > wave phasing line.
> >
> > Well, Tom's tower is probably tall enough - but how in heck would we get the
> > verticals far enough away from the tower??
> >
> > Charlie, K4OTV
> >
> > -----Original Message-----
> > From: Mike Armstrong [mailto:armstrmj@aol.com]
> > Sent: Friday, September 06, 2013 10:42 PM
> > To: Charlie Cunningham
> > Cc: ZR; Shoppa, Tim; <topband@contesting.com>
> > Subject: Re: Topband: Are stacked verticals feasible?
> >
> > 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-important skirt 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
> >>>
> >>>
> >>> -----
> >>> No virus found in this message.
> >>> Checked by AVG - www.avg.com
> >>> Version: 10.0.1432 / Virus Database: 3222/6141 - Release Date: 09/05/13
> >> _________________
> >> Topband Reflector
> >>
> >> _________________
> >> Topband Reflector
> >
> _________________
> Topband Reflector
_________________
Topband Reflector
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