I recently uncovered a surprising source of in-house r.f. interference on
40 meters, hindering reception on my beloved K2/100. I had already eliminated
such sources as defective touchlamp units, and replaced wall-mounted dimmer
switches that are infamous for the static they generate. That left me still
contending with a wide, noisy signal about every 10kc across the entire 40
meter band, including 7045 where Kevin conducts the Sunday ECN sessions.
I grabbed my handy KX1 and a loose coil of wire, clipping it to the antenna
input and using it as a direction-finding loop. In no time at all, it led me
right to the source of the signal .... our home security system! An oscillator
used in the device was radiating strong harmonics throughout the house on all
the wires running to the door and window sensors. Talk about a curtain antenna!
In this case, the cure is expensive because the central monitoring unit is
having to be replaced. It was not type-approved by the FCC. The new system is
guaranteed not to be a spurious generator on the ham bands.
I'd never thought of the KX1, or any of the little Elecraft rigs, as an rf
interference "sniffer," but they work ideally for that purpose. A properly
designed, handheld loop antenna might be required in tougher cases, but give
anything handy a try and see what surprises you uncover.
Happy hunting.
Dale -K6PJV
Sacramento, CA.
_______________________________________________
Elecraft mailing list
Post to: [email protected]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
