[sdiy] clock frequency shifter?

[René Schmitz]

At 00:51 09.04.01 -0400, you wrote:

>so: is there a way to take the output of a 5MHz crystal and vary it 
>semi-smoothly down to somewhere near 1 MHz? or alternately, a 
>very-simple VCO that does this range? could i just use an LFO circuit 
>with component values adjusted accordingly, or are there weird effects 
>that come into play? linearity and stability are obviously not very 
>large concerns. any suggestions are welcome (it's due in a couple weeks).


Hi Tom,

I wouldn't recommend scaling up an LFO, most of these use opamps as
comparators, which is ok at audio rates, but this doesn't work at
ultrasonic frequencies.

The 4046 contains a VCO that seems to be just right for this job. 

Cheers,
  René
-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159