de Mike VE9AA again. Can't seem to get this reply onto the list, but see
other messages showing up. I apologize if this is a dupe !
A couple folks asked me where I was getting my gain and F/B #'s from.
Fair question.
First of all, I have no doubt the S-meter on an IC-7410 is not accurate, but
everything is relative.
I just performed these measurements moments ago using my AA-230PRO as a
signal source about 200' Southwest of all 3 arrays and also equidistant to
the ref antenna which is an HF9V which also has raised radials. On 20 & 40
this is probably a pretty fair ref. antenna. On 80m, not so much.
I'll express them in S-units, and someone wiser than I can extrapolate to
dB/S-unit if they happen to know it as fact for this radio.
First, all 3-arrays have metallic clutter (or each other), or an 160m
inverted L very much in the near field.). A couple delta loops for 15m & 20m
are also close by.
All readings taken with a SW source/signal generator ~ 200' away.(my
AA-230pro)
>From my understanding an S-unit on a modern Icom is somewhere between 3 -
6dB ?....is it linear from S1-S9 (doubt it)
20m
HF9V - S7
Array - SW - S8
SE - S2
NE - S1-2 (varies a little with the wind.call it S1.5)
NW - S3
Gain over ref 3-6dB? F/B 18-36dB?
40m
HF9V - S5
Array - SW -S6
SE - S2
NE - S2
NW - S3
Gain over ref 3-6dB? F/B 12-24dB? Low due to being nested inside NW
quadrant of 80m array?
80m
HF9V - S5 (unfair reference)
Array - SW - S8
SE - S3
NE - S0 (could hear signal, can't measure it)
NW - S6 <ouch; would've thought # should've been lower here,
however this array aimed NW is aiming at all other antennas and a garden
shed, cars, etc. so maybe I should not be surprised)
Gain over crappy vertical 9-18dB? (real gain 3dB?) F/B Excellent @ 24-48dB
So, it's obvious it all doesn't work perfectly, and F/S seems to suffer a
little here and there, but compared to the reference antenna, they have some
gain and F/B is pretty good. F/S is fair.
I don't know if at only 200' away this is a fair or accurate test.
Mike VE9AA
Mike, Coreen & Corey
Keswick Ridge, NB
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