[Elecraft] [OT] A Very Quiet Day

Edward R Cole kl7uw at acsalaska.net
Fri Sep 11 03:43:47 EDT 2020


Here in Alaska, we have frequent power outages.  More often in winter 
due to wind storms knocking down wires.

A few years ago we bought a 6500w Honda inverter generator to provide 
emergency power.  Its large enough to supply the entire house 
load.  One of the interesting things was noting the drop in radio 
noise when power is off.  We see no lights in the neighborhood other 
than ours so any noise would be made in our house.  2m noise drop 
almost to S0.  Normal quiet times with commercial power runs 
S3.  Only see S2 or less on 2m when running our generator.  At times 
local noise on 2m rises to S7 which renders the band unusable except 
strong local signals.

I just set up my 6m eme system and measured S6/7 noise with the ARR 
preamp.  PR6 shows S3/4. ARR gain is 25-dB vs about 15-dB for the 
PR6, so I added a 10-dB attenuator in-line with the ARR preamp which 
now matches the PR6 noise floor pretty well.  ARR is closer to the 
antenna with 0.5 dB NF whereas the PR6 is about 0.7 dB NF.  Not 
really noticeable with local signals but makes a little improvement 
with weak eme signals.

When I first came to AK, I lived off the grid (about 2-3 miles from 
nearest power lines (town of pop 75).  80m band was S0 on my dipole 
at night.  Really heard well back then.  I now live 100 miles west of 
there in a buried utility area (2 to 5 acre parcels) which probably 
helps (though overhead lines are only 1/2 mile away.  HF is typically 
S5 noise with my K3 (preamp off).  I use the PR6 on 10m & 6m so that 
raises the noise floor a bit.  Our pop is 4,000 spread over 76 square 
miles with a city of 15,000 12 miles south.

Going to bush towns is no insurance for low noise.  I worked in a 
town 400 miles west of Anchorage (pop 3500) and tried setting up a 
long yagi on 2m on roof above the TV station.  Noise was over S9 (due 
to arc igniters in their furnace).  2m was totally unusable (trying 
for a long shot to Anchorage).  They ran a monitor on the AM radio 
station which blared horrible noise when they shut down the 
transmitter at night.

73, Ed - KL7UW
   http://www.kl7uw.com
Dubus-NA Business mail:
   dubususa at gmail.com 



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