[sdiy] Measuring filter response

[Gordon JC Pearce]

On Mon, 15 Aug 2011 12:45:30 -0700
David G Dixon <dixon at mail.ubc.ca> wrote:

> I once read in an old textbook (pre-computer, pre-digital scope) about using
> a slow sawtooth to ramp the filter frequency, and also using this saw to
> trigger the scope, then just feeding a sine to the filter and looking at the
> response.  Has anybody tried that?

That would be a "wobbulator", used for testing the frequency response of filters, amps, speakers and rooms and also generating saw sweeps for scifi sound effects in the BBC Radiophonic Workshop.  Essentially, a sine VCO swept by a sawtooth.

-- 
Gordon JC Pearce <gordonjcp at gjcp.net>