[Elecraft] (OT) - Unplanned Discovery

[stan levandowski]

Most people on this Reflector are well educated and intelligent.  
Apparently, I'm the exception because this one got by me.  I'm only 
owning up to this in the hope that it might help someone else on the 
Reflector. 

For the last couple of years I've been bothered by a high background 
noise level.   It happened on my K1, K2, K3, KX2 and KX3.   I attributed 
this to the fact that my antenna has been in my attic for the last 
fifteen years and propagation hasn't been good lately.


I just got official permission from the HOA to install an end fed wire 
outside.  I was thrilled.  I put it up.  The darn thing wasn't any 
better than the attic doublet.  Noisy as heck!  What a letdown!


So I'm laying in bed last night reflecting on how my little KX1 was the 
only Elecraft radio that never had noise problems and seemed to have a 
receiver quieter than my K3.


Whoa!  The KX1 always ran on batteries...could it be?????


I just took delivery on a brand new Kx33 Low RFI power supply a couple 
days ago. It was advertised in the last QST.   Previous to that, I've 
been using a Samlex 1235M.  For the heck of it,  I connected my K2 to an 
SLA battery and the noise was still there.  But when I disconnected the 
Kx33 power supply from the wall, the noise level dropped dramatically.  
Then I switched to the Samlex and the noise came back.  Back on the 
battery, the noise dropped again as long as the power supplies were 
unplugged and dead.


I have a laptop next to the computer.  When I pulled the plug on the 
laptop supply, the rest of the noise went away.  I was down to S0/S1 and 
CW signals were popping out all over the band again.  Running the 
computer on its internal battery did NOT contribute any noise.  It was 
the computer power supply.


Now that I am totally on batteries, I also appear to be immune from both 
the gas furnace and the dishwasher motor both of which caused me 
problems when using the AC supplies.  YES, I HAD CHOKES ON ALL SUPPLIES, 
CABLES, WIRE.


I've been on the air all day with my new outside antenna, on battery 
power,  making contacts near and far and I feel like I've hit the 
jackpot.  Since I'm totally QRP and CW, being limited to batteries is 
not an issue.


If you're going to check your own supplies out, remember they've got to 
be OFF/UNPLUGGED from the wall. Just disconnecting them from the 
radio/computer isn't enough.  It's RF.


73, Stan WB2LQF






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