[RFI] Noise - where do I start?

[KD7JYK DM09]

: I started a personnel rule that day... I will not do RFI hunting for
: anyone, (including myself), no matter what, until I see a power off
: test, for every event I work on.

What about things with batteries and UPS's?  You could be out in BFE, 30
miles from everything, plagued by noise, kill the power, even tear out the
wires, still have noise.  I have tracked it to shut off cell phones, shut
off cameras, shut off and unplugged computers, watches, et cetera...  All at 
the site, all affecting the person to some extent, none of which are 
affected by killing the power.  Even killing the AC mains only affects 
something on the mains that doesn't have another power source that may be 
causing other or more noise.

Kurt