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Old October 1st 06, 11:12 PM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 168
Default Optimising a G5RV

On Sun, 01 Oct 2006 11:32:09 GMT, Cecil Moore
wrote:

Owen Duffy wrote:
http://www.vk1od.net/G5RV/optimising.htm
Comments welcome.


Great job as usual, Owen. I would add a couple of
items.

1. Some commercial antennas, sold as G5RV's, deviate
from your information because they deviate from your
specifications and tuning procedures. They may need
to be tuned to your specifications.


Not just commercial ones Cecil. For decades I have taken an interest
in the detail of the "other station's" G5RV in QSOs, and they vary
widely.


2. The following statement is somewhat confusing.

Fig 1 shows the efficiency of a optimised typical G5RV.
Note that only three of these peaks coincide with an amateur
band, but 40m efficiency is 65% although not at the peak.


It is not a marvellous bit of prose, is it. I added the bit about 40
as a balance that although there wasn't a peak in 40m, 40m was well up
the curve. I will rethink a clearer way of expressing it.


The resolution of the graph makes it difficult to know which
three peaks are in which three bands. Like 40m, you might also
state that 15m efficiency is xx% although not at the peak.


Yeah, I didn't really want to deal with how good a "typical" G5RV was
or wasn't rather just set the stage for why it was worth fine tuning
in situ. I stated in my posting our newly minted hams like them, and
when you start with a power limit that is 10dB behind the average, you
don't need to throw more power away in the antenna system.

Owen
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