[sdiy] Pet Peeve

[jhaible at t-online.de]

> I remember building a PUT saw oscillator as a kid.  I put
> a jack on it to run my guitar into the trigger of it.
> The oscillator would lock on to harmonics, much like
> a PLL.  Lots of fun.  What memories.

Great idea !

In fact, a triangle oscillator that gets a signal
fed into its integrator (without the sign switching of
a VCO's control voltage), can exactly be described with the
equations of a 1st order PLL. What memories indeed -
my diploma thesis was an application of this: I built a
FM radio demodulator around a triangle oscillator.
(No PD, no loop filter.)
Which was great fun - but I bet not half as much as
your guitar-PUT-PLL !

JH.