[sdiy] voltage-controlled AM radio tuning

[Paul Perry]

The cap ratio has to vary as the square of the frequency range ratio, so 
that means a ratio of about 10 to 1.
You might find that to get a range like this, the max applied voltage will 
bewell over 10 volts.

What is worse, is that you will need to have at least two tracking systems - 
the RF preamp and the local oscillator.

paul perry Melbourne Australia