The reason for the "chuff" is because the receiver is probably muted for the
relatively long settling time of the synthesizer. For a 1kHz tuning step,
and a value of N of 11,000, for instance, you need to have the Omega_d of
the loop filter to be set at approximately 15Hz in order to have adequate
reference sideband suppression.
The settling time will be about 100mSec, with a 50 degree phase margin.
This settling time would be unacceptable.
The workaround in this situation is to use a DAC to pretune the VCO to the
required frequency; this way, the loop filter doesn't have to deal with a
very large step response (and a long settling time). If the settling time
could be set at 5 to 10mSec, the tuning would feel instantaneous.

Pete

donutbandit wrote in message
...
"Pete KE9OA" wrote in
:

I like the feel of that tuning knob.

Tuning knobs are great, as long as they don't jump in 1 kHz increments and
"chuff" when they do.

That's why nothing will ever replace a true L/C combo for me.