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 <[email protected]> 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 <[email protected]> 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" >> <[email protected]> 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:[email protected]] On Behalf Of ZR >> > Sent: Friday, September 06, 2013 9:26 AM >> > To: Shoppa, Tim; [email protected] >> > 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" <[email protected]> >> > To: "Carl" <[email protected]>; <[email protected]> >> > 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 [[email protected]] on behalf of Carl >> > [[email protected]] >> >> 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
