Even in a quiet rural location, the limiting noise on 160 will be external
atmospheric noise. Improving RDF will generally improve your signal/noise
ratio against the atmospheric noise. There are exceptions when there is a
source of high noise, like thunderstorms, in the same direction as the signals
you are receiving. In that case, improving RDF may not help so much.
I have a couple antennas whose RDF's differ by about 4 dB. That's a pretty
significant difference. When I switch back and forth between the two with both
antennas aimed at the direction of signal arrival, the improvement in S/N with
the higher RDF antenna is very obvious to my ears, especially when the received
signals are weak. From that I would surmise that even a 1 dB difference in RDF
would be discernable when signals are weak, although the difference won't be
dramatic.
One thing to keep in mind is that increasing the RDF of an antenna system
causes an unavoidable narrowing of the beam pattern. This means the RDF
advantage is realized only in an increasingly narrow range of angles. This
means that the S/N will drop off more sharply for signals off the peak of the
antenna's main lobe.
73, John W1FV
-----Original Message-----
From: Topband [mailto:topband-bounces+john.kaufmann=verizon.net@contesting.com]
On Behalf Of Kenny Silverman
Sent: Tuesday, August 23, 2022 4:07 PM
To: topband
Subject: Topband: Beverage upgrade question
In a rural area with no significant man made noise, if you redesign a beverage
for better RDF when do you start to notice a difference?
I’m considering upgrading my single EU beverage at 625’ (190m) to a pair in
echelon where will each be 550’ (168m) with 20’ (6m) spacing . The increase in
RDF is 0.8 dB - will it be noticeable?
I realize if there’s noise in a direction where you reduce the energy you will
better hear the difference , but my EU beverage is quiet. Though the F/B
change will help with thunder storms off the back.
Overall I tend to receive better than I transmit to EU.
73 , Kenny K2KW
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