I own a Fluke 6060A/AM (10 kHz to 520 MHz) synthesized signal generator that appears to be a source of noise. For example, if I set it to 1 Mhz and tune an AM radio to this frequency, I hear a light crashing noise and an occasional pop/click. If I put a scope across the radio's speaker, I can see the pops/clicks. Some other facts:
(1) I've poked around the power supply with my scope and find nothing unusual. (2) The magnitude of this noise is independent of the generator's RF output level. (3) When I switch-off the generator's output, but keep it powered and running, the noise and clicks goes away. (4) The RF output of the generator is clean. No noise or pops/clicks are "floating" on the signal. (5) The noise and pops/clicks only appears after, say, a 10-minute warm-up.
Other than this, the signal generator work fine. I still suspect the power supply--bad capacitors? Or perhaps some other noise source in the house is getting a free ride at the generator's expense.
Any suggestions?
-Dave