Radio scan controller?

[Paul Perry]

At 02:03 PM 6/11/98, Scott Gravenhorst  wrote:

>Switched capacitors are normally used in an RC tuned circuit.  The capacitor
>is switched in and out of the circuit with a clock signal.  The duty cycle
>of the clock controls the effective capacitance.  I don't know how that
>would effect the tuning of an LC resonant circuit since both the L and the C
>are storage elements, where as in an RC circuit, only the C is.  If it worked
>at all, I think the clock for the C would have to be much higher, like twice
>the frequency of the LC circuit.
.all this is true.....
i should have changed the header, as I was replying to a subsequent query as
to the
analog & audio applications of varicaps.
Having said this, though, possibly something could be done with pin diodes 
switching at 200MHz, to switch caps in a shortwave RF set.... but the filtering
compexities would not make it worth it, I expect.

paul perry melbourne australia
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