[sdiy] Frequency shifters, again

[Don Tillman]

Hey JH,

I forgot to speak up before when you first mentioned this topic...

I've seen this before.  (!!!)  It was an old issue of the Journal of
the Audio Engineering Society, roughly around 1974.  

It was a voltage controlled filter built with two balanced modulators,
a fixed filter between them, and a VCO.  At least two pages long, with
a block diagram.

Unfortunately that's all my feeble memory can provide.  It probably
wouldn't be difficult to hunt this down at a university library.

  -- Don

-- 
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com