[Richard Crowley]

"Mike Rivers" wrote ...
wrote:
Does using a single diode as a half power step introduces RF noise as
well?

Yes. The RF interference is a result of the non-symmetrical (around
zero) waveform created when the diode cuts the bottom half off the
waveform. But it might be a bit less noisy than an SCR which chops off
the sides of the waveform.

Not sure that is true. Using a simple diode limits the power
to either the positve or negative half-cycle, but 0.6V is close
enough to zero that we can call it "zero-crossing". Using a
simple diode has other problems, but generating RF hash
has never been one of them IME.