Topband: switching pwr supply noise problem

[Roger Graves]

Story of a ham's Sunday.

I finally get around to trying to track down the noise sources that 
have gradually sprouted up on 160. Buy a portable shortwave rx 
and proceed to walk around the neighborhood to find which of my 
neighbors is guilty of having something nasty. 

Hmm, noise decreases as I leave the front door and walk down the 
driveway.
OK, could this be? So, procede to go back in the house and walk 
around the house. Lots of noise. So, to the circuit breaker. Open 
one at a time, shrieks from various family members, flashing 
clocks everywhere. Noise doesnt go away on any breaker. Repeat, 
more shrieks. OK, throw that big house breaker lever. RF noise 
drops. Hmm. OK, open all circuit breakers, and close one at a 
time. 3 separate circuits show increase of noise. Take a break.

Circuit 1, hamshack area, is loudest! Unplug ethernet router pwr 
supply. Big drop in noise. Unplug cable modem pwr supply, noise 
goes away. Both are small switching pwr supplies.

Circuit 2, daughter's room. Mass of wires, cables, candy wrappers, 
month's worth of school lunch containers behind desk. Unplug one 
thing at a time. HP computer printer power supply, switching type, 
is the noise source.

Circuit 3, living room. Sony TV (when on) and Sony VCR (whether 
off or on) turn out to be generating 160 mtr noise.

Wind power cord on a toroid (10 turns on 77 mix). This kills the TV 
& VCR noise, progress! This does nothing for the louder printer, 
router and modem power supplies though.

Leave those power supplies unplugged and operate on 160, with 
quietest noise level in some time!

Anybody have any suggestions on quieting those little noise 
generator power supplies? My only thought at the moment is to 
build new transformer supplies or to substitute an old computer 
power supply that is RF quiet.

Thanks for any suggestions,
Rod
VE7VV
Victoria, BC