[RFI] Local Noise Environment

Pete Smith n4zr at contesting.com
Sat Feb 14 10:13:20 EST 2004


I am trying to figure out my local noise environment and understand what 
(if anything) I can do to correct it.

On my shunt-fed tower, in daytime, the S-meter on my Mark V (which is 
extremely generous below S9) reads a steady S9 +10 with the radio in USB 
mode and the standard filters in use.  Switching to a K9AY loop 350 feet 
away from the tower (with a 20 dB preamp) drops the level of the noise to 
S7-8.  I have listened to the noise in both USB and AM positions, and do 
not hear the 60 Hz AC arc sound that I have gotten used to in my efforts to 
track down power-line noise.

I can't rotate the loop, so I tried listening on 80, where I have a 
4-directional K3LR-style lazy-vee array, and the noise definitely peaks, by 
a few dB, in one direction, and is materially lower in the opposite 
direction (the array has a wide forward lobe but pretty substantial F/B ratio).

I can make some recordings if anyone with an expert ear thinks hearing it 
would be useful.

73, Pete N4ZR
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