On Mon, 17 Oct 2005 16:05:54 GMT, Cecil Moore wrote:

Owen Duffy wrote:
More importantly, if you found any faults with my analysis, let me
know?

Just found one and replied to your posting. You and Cebik
seem to disagree about 12m where you say it won't work on
any WARC band and he says the impedance at the twinlead/coax
junction is "Resistive (90-100 Ohms)", i.e. SWR=2:1

No, I said:

"Contrary to oft stated views, the Classic G5RV is not an all band
antenna, it:
* does not have acceptable feed performance on 1.8MHz;
* does not have acceptable feed performance on any WARC bands;
* does not have acceptable feed performance on 28MHz."

Two main factors were in my mind in determining whether performance
was "acceptable", they we
- the magnitude of the losses on this particular model in-band for the
band in question; and
- whether the losses changed rapidly on adjacent frequencies, such
that installations with small differences (eg height, earth parameters
etc) were not assured of acceptable losses.

For example, it is possible to tweak a G5RV a little to minimise the
feed losses on 10.1MHz, and they can be low enough, but it is a very
sharp notch and likely to be not realisable with seasonal changes in
soil moisture etc.

I have reviewed the specific case you mention about 25MHz. Two of the
feed arrangments are marginally under the criteria that I set, but
they are under it and for consistency they should have been included
in the "acceptable" category. Omitting them was an error on my part.

I have ammended the article accordingly Cecil, thanks for the
feedback.

It is important to keep in mind that the article is analysis of a set
of common feed configurations of a dipole at a specific height over
specific ground, and that the results may vary in other
configurations.

Owen
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