Here's my personal experience about noise coupling and reradiation.
I've drawn my antenna farm to show antenna proximity. I graphed the typical
noise of each antenna as indicated on my S-meter. The plots shown below the
noise graph are my SWR curves on the 160m Inv-V and verticals.
~
/
Beverage "A" --- /
NOTE: NE/SW /
Not to scale. (in clear) /
/
/ 61' loaded phased
Switch o verts (130' spacing)
|\
<-- West X To Rcvr \ X East -->
\
\
--POWER LINE--- ------------- ------------ -------POWER LINE---
\
\ /
\ /
Beverage "B" --- \ /
SE/NW \ /
(between verts, \ /
pwr line, and \ /
INV-V) \ /
/
/ \
Tower ------- X \
| \
++ HOUSE++ | \
| \
160m INV-V --- | \
| \
| \
| \
\
If you sweep across the band looking only at my S-meter,
typically my S-meter indication for noise on each antenna is:
+10 dB/S9
| /\ -- Two 61' phased verticals
| / \
S9 / \ . . . .
| __/. . \__ .
|... ..... NW/SE Beverage "B" mixed through
| verts, pwr lines, Inv-V
S2
|- - - - - - - - - - - - - - - - - NW/SW Beverage "A" in clear
|__________________________________
1.8 MHz 1.9 MHz 2.0 MHz
SWR for Verts and Inverted-Vee:
2:1 ./ -Verts (DXing) . -Inv-V (Local Ragchewing)
| \ /. .
| \ / . .
| \ / . .
| \___/ . . .
|__________________________________
1.8 MHz 1.9 MHz 2.0 MHz
There is a correlation between the nearby antenna SWR (resonance) on beverage
"B" as far as noise is concerned. As a test, I lowered the Inv-V and the noise
decreased on beverage "B" between 1.85 and 1.95 MHz. For all practical
purposes beverage "B" at my location doesn't help receiving very much due
to the proximity of the nearby antennas.
What I ended up doing at my station was cutting the Inv-V down to
3.5 MHz and using it as a sense antenna for my MFJ noise canceller.
I removed beverage "B" and to the NW/SW. I definitely improved my
receiving ability. (Previous post regarding MFJ vs ANC-4 noise canceller)
A detailed EZNEC analysis of my phased verticals can be seen at:
www.texassoftware.com/ click on PALS button and download K5QY
73, Dick -K5QY
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