[Elecraft] HF Verticals?

[Tom Hammond NØSS]

George just said EVERYTHING I wanted to say, and MUCH better than I could 
have EVER said it.

Toward the end of his reply, George makes reference to Walt Maxwell's 
"Reflections II", which, though I've not read it, I understand is as good 
as his first book, "Reflections" which I HAVE read, but which is no longer 
in print.

For anyone interested, an EXCELLENT intro to both of Maxwell's works is now 
available at the ARRL web site. This is a PDF containing the contents of a 
series of QST articles by Maxwell (W2DU), entitled "Another Look at 
Reflections", which appeared in the early 70's. The series of articles was 
never quite completed at that time, but regardless, they contain some of 
the VERY BEST antenna theory you'll find anywhere. Even if you blow right 
by the math (and it's certainly there if you choose to get 'into' it), the 
articles are written so just about anyone will be able to gain a 
significantly better understanding of antenna matching and SWR (which is 
the crux of the series).

To access this article, go to http://www.arrl.org and in the SITE SEARCH 
field at the top of the page, type in "ANOTHER LOOK AT REFLECTIONS" and 
click on GO. Once the search returns its results, "REFLECT.PDF" should be 
at the top of the list. RIGHT-CLICK on this link and then, when prompted to 
do so, select SAVE FILE AS (or whatever similar choice you are presented by 
your browser) and SAVE the file to your hard drive. DO NOT attempt to read 
the article on-line by merely clicking ON the link and paging thru it. The 
article's much too long to be viewed on-line.

This should be a "must-read" for all hams.

73,

Tom  N0SS


George, W5YR wrote:
>John, I really don't know if you are anal retentive or not, but an antenna
>can be resonant and still present a 10:1 SWR to the feedline.
>
>The absolute magnitude of VSWR is not an indicator of resonance.
>
>Resonance is solely, only and always the condition of a tuned circuit in
>which the impedance at the port of interest is purely resistive or real.
>The real component may NOT be the same as the Zo of a transmission line,
>hence the SWR can be other than 1:1.
>
>Resonance has nothing to do with SWR. SWR is determined solely by the ratio
>of the driving point impedance of the antenna to the Zo of the transmission
>line, or vice versa.
>
>It is your choice to place so much emphasis on SWR but the facts are that
>it is relatively unimportant to the actual radiation performance of an
>antenna. An antenna fed with a line having any SWR will radiate all the
>power it receives. If the line is low-loss, it can easily be the case that
>more power is delivered to the antenna over a line with a 20:1 SWR than a
>line with a 2:1 SWR. It is all a question of relative line loss, frequency,
>line length, etc.
>
>But the resonance or lack thereof of the antenna has very little to do with
>it. Every antenna that I use, except for my Butternut HF9V vertical, is
>non-resonant in any amateur band. They all work great on 80 through 10
>meters, and most of my operating is QRP CW where efficiency counts.
>
>With all respect, John, a review of the Antenna Book on the topics of
>antenna resonance might be worth your time. Walt Maxwell's "Reflections II"
>will give you an entirely new outlook on this subject. Resonance is
>convenient for matching purposes, but that is about all it buys for you.