[Elecraft] (OT) - Unplanned Discovery

Edward R Cole kl7uw at acsalaska.net
Mon Nov 20 01:57:53 EST 2017


Up here in Alaska its not unusual to experience loss of commercial 
power (often due to Inclement wx or avalanche).  I've noted how quiet 
my radio is when no one around us has power.  Even running our 6500w 
Honda invertor-generator its very quiet (which also tells my noise is 
coming from neighbors and not my appliances).

Also, I have found the IBM Think pad (laptop) is very quiet (even 
with charger).  I think this largely because the case is metallic and 
not plastic.

This story does remind us to periodically check our house for noise 
sources - might be pleasantly surprised.

I have been plagued by S9 level interfering noise on 144-MHz for 3-4 
years.  Recently I checked coax loss on some lines when I had to roll 
up all for some house work.  I found excessive loss in my two 
130-foot LMR-400 Rx lines (runs from preamps on tower to transverter 
in house).  Since replacing the lines I think I have lessened the 
interference, making suspect some may have been due to passive 
intermod in those lines.  Loss was probably moisture caused corrosion 
which might interact with out of band signals.  Passive IM is tested 
by the cellular industry at their tower sites.

I still see occasional noise interference but its less often and less 
problem-some.

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



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