Good Day All, I've seen references in ON4UN's book regarding the use of "linear loading" to compensate for short physical vertical antenna heights...and I recall reading somewhere once where Bill Orr
Author: "Chortek, Robert L" <Robert.Chortek@berliner.com>
Date: Tue, 23 Feb 2010 10:15:41 -0800
Hi Ed, FWIW, I had a linear loaded elevated vertical for a few years, and then switched to a 60 foot base loaded (8" air core, made of 10 gauge wire) also elevated and my "impression" is that the bas
I thought there might be significant loss due to the shortness of the elements, but I didn't really know how much, so I put it on EZNEC. I first started with a full size 160 bobtail with the top at 1
Eddy I have seen better approaches to this in the literature. BTW I think that linear loading is considered very marginal at lengths 50 percent or less than normal resonant lengths. What has been do
I have used a slightly less ambitious antenna Ed for 3 years now . I use a 76ft vertical with a base tuner for 80m. In parallel with the vertical are 2 x 24 ft verticals spaced about 18in with 18in o
I'd disagree with this comment. While there is some pattern distortion, it is not a waste. The Half Square can still be very effective corner fed. I had one up for years and it worked VERY well. An
Feeding the bobtail at bottom / votage feed is a high ohm (several thousands) and are not very dependant on radial screen, just dc to earth. As been said the best you might want to experiment with is
"...The feedpoint impedance was 13.5 ohms. (Feedpoint impedance of the full size bobtail was 41 ohms.). Of course you can feed these from the bottom of the center element too, but I didn't simulate t
No I didn't model a Robert Tail. It was a Bobtail. There are two methods for feeding a Bobtail, either voltage fed at the bottom of the center element or at the top of the center element (a low imped
"...No I didn't model a Robert Tail. It was a Bobtail. There are two methods for feeding a Bobtail, either voltage fed at the bottom of the center element or at the top of the center element (a low i
It may be true that a "classic" Bobtail is fed at the bottom, but that doesn't mean feeding it at the top won't work. If you want to call it some other name when fed at the top, have at it. If you ta
Author: Mike Waters W0BTU <mrscience65704@yahoo.com>
Date: Thu, 25 Feb 2010 14:44:41 -0800 (PST)
[snip] There you go. Top loading is the preferred method in nearly every instance. 73, Mike Waters W0BTU _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
While we're on the subject of Bobtails - I've been considering a design that is slightly different than what you normally see. What if one were to use a cylindrical tube for the center element, and r
Interesting thought Wayne! It might work, but guess you would have use a RF choke on the coax at the bottom of the element. On the negative side is that it would be at a hi-z point of the coax where