----- Original Message -----
From: "Tom W8JI" <w8ji@w8ji.com>
To: "topband" <topband@contesting.com>
Sent: Sunday, December 02, 2012 12:46 PM
Subject: Re: Topband: Beverages 2 basic questions
resistors. Id guesstimate the general F/B to be over 20dB on 160. My
feeling is that performance could not be duplicated by various other
loading methods. If somebody wants to make real world comparisons it
might be beneficial.
I looked at slinkys when I lived in Conyers. None of this is magical or
difficult, nor are antenna slinkys or helical loads "special".
** After I brought Slinkys up on the forums and on 160 in the late 80's and
90's. Your comments then were just what I expected.
The behavior
is the same as a series of lumped inductors spaced fractional wavelengths
along the antenna.
** Maybe on paper which is why Ive asked others to make the real world
comparisons. I find it hard to believe that a wire being randomly
interrupted by a lossy lumped inductance plus capacitance can privide
identical results.
There is a certain optimum phase shift along an antenna's length. There
are many ways to accomplish that, and if the resulting current
distribution and phase is the same the results will also be exactly the
same.
** Nothing beats a helice for a loading device for a steadily progressing
phase shift. No guesswork needed. It even worked for high gain UHF
transmitting antennas.
Sometimes, like
with long antennas fired away from the feedpoint, we don't want that
delay. We actually might need a phase advance.
** Thats not related to the subject under discussion.
The only thing magical about slinkys is how they can go down steps without
feet, and without holding on to the banister! I never have figured that
out.
** No magic involved in how they work as an antenna or as a toy, the toy
part has been thoroughly explained ages ago.
Carl
KM1H
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