Quote Originally Posted by KJ3N View Post
Properly designed switching supplies don't generate sufficient noise at HF. I've just about done away with all my analog supplies.

See this from August 2009 QST: http://www.centralmiarc.com/docs/Reviews/dj175t.pdf
I agree that properly designed switchers have come a long way in communication applications. However, the one he has linked to is probably a wideband transmitter covering DC to light.