Tom described the sound very well.

Most switching power supplies and chargers that I have heard will add 
some whine, or have more hash associated with them than Tom's 
recording shows, but you can't rule out those devices.

A previous post covered part of the first tracking steps, but having 
been on these witch hunts myself a few times, here is a bit more to 
consider.

Don't just turn the devices off, completely disconnect them from the 
AC power. This is because most of the power supplies in televisions, 
microwave ovens, etc, remain powered and hot at all times.

If possible, connect the TS590 to a battery, then kill your power 
supply just to be sure the source isn't sitting on your desk.

If you can't connect the radio to a battery, proceed with the next 
step, skipping the circuit breaker which controls your radio, then 
borrow a power supply from someone else long enough for a test.

With the radio volume cranked up loud enough for you to hear, shut 
down everything in your breaker box. If the noise goes away, bring the 
breakers back one by one until it returns. Then, start eliminating 
everything on that particular breaker.

If you haven't done so yet, try driving around your neighborhood in 
your mobile to see if you hear the noise anywhere else. If you don't 
have a 10 meter mobile antenna, use whatever antenna you have that 
will hear the noise in your driveway.

Some will laugh at this one, but I've seen it work before. Crank up on 
10 meters, with as much power as your amp will give you. If the noise 
if from a modem or from a video source, a strong dose of RF will 
sometimes change the sound of the noise at least temporarily.

About 15 years ago, I once forced a cable company to take action by 
employing that technique on 2 meters shortly after they came to my 
door and ordered me to "stop operating that CB radio before we call 
the FCC." After telling the guy to go ahead and call them, I called 
his human resource department, and then wrote a letter to the company 
with a copy to the FCC office in my area.

Three days later, I had 3 cable engineers from the company's main 
office asking me to please help them find their problem.

In this case, the problem turned out to be no less than 6 bootleg 
cable connections in the neighborhood. The noise would go away because 
whenever I transmitted, those clowns would change their television to 
another channel.




Mike Duke, K5XU
American Council of Blind Radio Amateurs