On 10/5/2014 6:34 PM, gareth wrote:
"rickman" wrote in message
...

I'm not sure I understand the issue. But if you want a digitally
controlled oscillator for your mixer why not just make a digitally
controlled oscillator for your mixer? That is already there with the
Si570. Why the complex usage of using the existing oscillator and then
switching?

The older RX, with its mechanical tuning, perhaps loaded with
a flywheel, is a much more ergonomic tuning mechanism than
anything that has come out of the semiconductor world.

Therefore, use the existing tuning dial in the first place, and then
lock with the 2nd oscillator.

There are controls which can be just as nice to spin as any existing
tuning dial and can control a digital circuit.

What does the existing knob control, an air capacitor? That dial knob
can be connected to another type of control which can be read by the MCU
to control the Si570.

--

Rick