Owen Duffy wrote:
Some months ago I put some thoughts together to assist our newly
minted 6-hour hams who seem attracted to either short end-fed wires
(although they refer to them as long-wires) or G5RVs.

This article deals with optimising a typical G5RV (as distinct from an
optimal G5RV).

I ceased efforts when it became apparent that the procedure was beyond
the base competency level for our Foundation Licence, and therefore
beyond the target audience. (Another issue was that it required
transmitting a test carrier on 20m which is not one of their permitted
bands, so technically they would need assistance.)

Nevertheless, I looked over it today and fixed a few typos.

http://www.vk1od.net/G5RV/optimising.htm

Comments welcome.

Owen
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# measure the VSWR at different frequencies in the 20m band, initially
VSWR should be quite high, and higher at the high end of the band;
# shorten the line a little at a time and repeat from 5 until the VSWR minimum (should be close to 1) occurs at 14.15MHz.

A nice article indeed. The above quote is from the set-up section. My
take is that this empirical approach requires almost no knowledge of
velocity factor at all. In fact, the article recommends against using
vf values listed or tabled in catalogs from suppliers. The reader is
instructed to find the vf ostensibly by experiment. This empirical
approach is the "old school" ham approach that I grew up with: cut and
tweak until you get what you want.

This is where we still live.

Owen, thanks for listing your article. Electrical length is indeed
important. Finding it by experiment is the process. I guess what I'm
trying to say is that, if you can't rely on published vf data and you
have to determine it empirically, you might be able to design a
perfectly good antenna, barely considering vf at all...just measure and
cut and measure and cut and...

John
AB8O