Aaron Kreider wrote:

I have a rfi noise that is throughout the entire shortwave spectrum
(0.1-30 mhz) at about an equal strength - it occurs approximately
every 60 khz (and sometimes every 30 khz).

Do you also see this on a TV set with external antenna/rabbit ears (NOT
cable)? Try low VHF (channels 2-3-4).

The noise is very strong - S9 - S9+20 db, on a very short antenna (6
feet) to my Drake R8, despite my radio being 25 feet or more from the
noise source. The noise comes from a nearby appartment.

How do you know that it's from a 'nearby apartment' and not from outside
the building? Do you have a battery operated receiver that you can use
to check outside?

The noise is 24 hours/day and has been going on ever since I moved
(over 1 year). It occasionally drops in strength for 1 second. A
couple of the noise spurs have a beep noise that is happening once per
second (could it be some kind of clock/timer?). It generally sounds
like a digital hash (eg more of a hash than a buzz sound).

I'm wondering - what kind of device would produce this noise?

Could be *anything*. If you are sure it's originating in the building,
try working with the super or the building maintenance manager. Also,
see if any of your neighbors are getting any radio or TV
interference...that will give you more leverage with the super.

Sorry to be so brief, but numerous entire books have been written on
interference tracking. Hopefully, this will at least point you in the
right direction and allow you to gather a little more information for us.