Here is something I posted a few months ago to the Topband reflector regarding this subject: -- How helically wound verticals really work: The concept of the helically wound vertical (HWV) is appeali
Even a knitting needle will do the job. ( joking ) Jos on4kj --Message d'origine-- De : towertalk-bounces@contesting.com [mailto:towertalk-bounces@contesting.com] De la part de Rick Karlquist Envoyé
Hmmm. Years ago I had a yagi that was made this way by a company called Kirk. It was a 40 meter beam and had fiberglass elements that were helically wound. Never liked the thing but always attributed
Rick, A very interesting topic! When I try modelling a helical vertical in EZNEC (zero wire loss) and then compare it with the same length straight vertical (zero wire loss) I do see a slightly incre
Modeling is only a numerical simulation of the real world... Adding series resistance in the form of more turns of wire in a given linear space is vastly unlikely to increase efficiency in the real
On the group's average 0.5dB accuracy measurement range??? :-) I don't see anything in there that is a reason for implicit mistrust of the model. A helical is better than a high Q base loaded vertic
The point about HWV's is not "do they work?" but "are they worth the trouble to build?". If you can cover the entire antenna with windings, you can just a well, with a lot less work, cover the center
I can't think of any advantage to a helically wound antenna. Structurally they are more complex, and electrically they have several disadvantages, most of which have already been pointed out here. I'
But a center loaded vertical has a high profile, high wind drag, and is more fragile than the helically wound vertical. Some times that is a problem and sometimes it is not. If not, then the decision
How so? Even a 0.5 inch cross section the length of a shortened 40m or 80m antenna adds up to more area than the cross sectional area of a coil, with a greater percentage of it up high where the leve
This is a straw man argument. You are comparing a 1 1/2 inch diameter HWV with a center loaded vertical using, say, a "bugcatcher" type coil. Suppose the center loading "coil" is constructed just lik
Dan, My model had a 1ft straight wire at the base, with 10ft of helical above it. I used 240 turns - couldn't do more without running out of EZNEC segments. The source was right at the bottom of the
Not for self construction. However, if one were in the antenna selling business, helical winding could provide a discriminating (and potentially patentable) feature. Company A could say: we're sellin
As they used to say in the Camel Filters commercials: "Ya gotta have a gimmick" Rick N6RK _______________________________________________ _______________________________________________ TowerTalk mai
YES! The problem, of course, is that you may need both, in which case I would use as much top loading as possible (multiple wires, longer) and add some inductance near the top of the vertical section
Hardly. I'm comparing a lumped inductance in the center to turning the entire antenna (or most of it) into one long linear loaded antenna. Yes, that's what center loaded does to get the required indu
"Smart" is good, but remember "there's no free lunch" Gene / W2LU _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@cont
One way of achieving lots of top "capacity loading" is to stick a remotely tuned mobile whip on the top of the vertical. When it's below resonance it's capacitive and variable. In the 1970s a local h
Dave, The mobile guys have that worked out and tested... Put the coil at roughly 60-65% up the vertical and add a top hat... The winners at the mobile shootouts use that layout... denny / k8do _____
This post should have shown up yesterday, but instead of converting to plain text it bounced which I didn't receive until this evening. Working a lot with both materials I seriously doubt the above s