[Boatanchors] interference

[N4ue@aol.com]

One thing to check is any switching power supply. Although some operate in 
the 40 KHz region, during a recent analysis of several modes, I found the 
strongest harmonic (on one unit I had) right on 7.040 MHz. Yep, I was trying to use 
it to power my QRP rig.......RIGHT on the CW calling frequency! Interesting to 
watch these harmonics on a spectrum analyzer. Especially during power on and 
off. Talk about a sweep generator......
Some are MUCH worse than others.

Regards,

ron
N4UE