Why we are talking about A B test knowing that the ionospheric signal is
fading up and down at least 10dB!?
This can be verified by anybody having a stable carrier as a receiving
signal and monitor it for few minutes...
For a proper A B test one should switch A B very fast and record
synchronously the amplitude! This is the only A B test that can be made
(with low cost setups).
How we test really depends on what we need to know.
The key to accurate testing is time span of the tests over minutes and many
days or months, not second by second in a short span of life. It's silly to
conclude a change with one day or even one week of testing, unless it is
ground or direct wave.
The proper way is multiple tests at multiple times averaged over time. My
tests ran at multiple times of day over many months through many seasons,
looking at pages and pages of logs.
I didn't care if an S unit was 2 dB or 20 dB because I had no interest in
picking quantative changes, I only cared which was noticeably better over
time. Also, as a factor, I would switch from omni to four square, which I
know is very close to 6 dB. That was always 1-2 S units, which is typical
for the 3-5 dB most people have for an S unit....not that the exact dB
matters at all when we are only after which is better.
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Topband reflector - topband@contesting.com
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