Sometime last year I started a thread about the RF noise from wall
warts.
http://home.computer.net/~pritch/shortwav.htm

Telamon and I discused the best values of the diode "bypass" capacitor.

For those inclined to do the job "right", here is a link to a very
detailed method.

http://www.hagtech.com/pdf/snubber.pdf

Enjoy.

Since noise limits my reception, I try to reduce it to as low a value
as I can.

Terry