ODP: Frequency multiplication

Roman Sowa rsowa at WizjaTV.pl
Tue Sep 1 13:59:36 CEST 1998

I got an idea for you...

If you had a sine VCO, you could wave-shape it through squareing device
(like multiplying the signal by itself, maybe in a precise RM or some
function generator - AD633 if i recall)
You get sine squared which actually is a cosine with doubled frequency
and DC offset. Remowe DC offset and square it again. You get quadrupled
frequency sine wave, and so on, till 32 times normal F is acheived. 

Another way to do that:
Take triangle (bipolar) wave and rectify it. You'll get another triangle
with doubled frequency, half the amplitude and DC offset. Adjust gain
offset, and rectify again. When you do it 5 times, the output wave would
be of frequency 32 times higher than the normal one.

there's a trick: rectified triangles must be linear all the time and
with not a bit of
DC offset. Otherwise the owerall wave won't be a "clean" triangle
i.e. pulses within 32-cycles period will spread sort of randomly.

I got totally different another idea for multiplying f. It's simpler as
a concept,
but can be very unreliable if done bad, and does not work with LF.
Let me know if you want me to use your bandwidth for it. 


> -----Oryginalna wiadomość-----
> Od:	Tony Allgood [SMTP:oakley at enterprise.net]
> Wysłano:	30 sierpnia 1998 22:33
> Do:	synth diy
> Temat:	Frequency multiplication
> Hi all,
> I want to make a high frequency VCO, 32 times the normal frequency, to
> use
> as a driver osc for a walsh bank. 
> 4. I'm open to any other ideas.
> Regards,
> Tony Allgood, Cumbria, UK

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