[CTSARA] RF In The Shack -- One Ham's Story

[Jon Perelstein]

As some of you know, I've been having problems with digital modes and SSB on my 
K2 for about the past two months.  With the help of Tony (KB1SUN) and Stan 
(WA2NRV), I was able to determine that the problem was on 80/75 and 40.

Since then I've been testing and testing and testing.  And borrowing various 
pieces of equipment from people -- an oscilloscope from Fred (K1FC), a Cantenna 
dummy load from Curt (W1FSM) and a few other things from other people.  Elecraft 
support had me testing the SSB module, and testing, and testing.  We couldn't 
find anything wrong with it.  They even had me re-solder the ENTIRE module "... 
just in case".

And then I was talking with Vlad (W1ZP) and he asked "what does the signal look 
like into a dummy load?".  Well, I had never actually scoped the signal when 
operating into the dummy load.  I had scoped individual components, but I had 
never scoped the output signal.  So I did.  The signal looked perfect. 

So forget about the rig.  It's probably a problem with the RF into the shack (my 
antenna is close to the shack).  Various people suggested trying a different 
antenna, so I disconnected my dipole, set up my Buddipole in the farthest corner 
of the back yard, and tried that.  Still a problem.  Not as bad, but still a 
problem.  Back to Curt, who went through a list of possibilities that included 
RF into the power supplies (my Samlex power supply and the power supply for the 
Dell Inspiron laptop that I use for digital).  I put both on battery (computer 
and rig) and all of a suddent the signal was fine.  Reconnected the dipole, and 
the signal was still fine.  Re-connected the Samlex, and everything still fine. 
 Re-connected the computer's power supply and suddenly I was looking at a signal 
out of Nightmare on Elm Street.  A new Dell Inspiron computer, that I now 
realize I had put into service about two months ago!!!

So tomorrow I'm heading out to Radio Shack to buy a LOT of ferrite beads.

There are two lessons from this:

1.  RF can get into the shack in all sorts of interesting ways.

2.  We have a LOT of resources in this club -- and in GNARC and in WECA and in 
GBARC -- who are glad to lend a piece of test equipment and lend a hand in 
solving problems.  Seven different people from three different clubs had a hand 
in helping me to solve this problem.  They loaned me equipment, they loaned me 
their experience, and they loaned me their brains.  If you're having a problem 
with ham radio, ask people.  Post it on the reflector.  The help available is 
amazing.

Jon
KB1QBZ

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