[sdiy] Tonewheel questions

[Harry Bissell Jr]

My method would be to use retro-reflective optical
sensors on a 12" diameter cardboard disk carried on
a turntable platter.  speed control would be
excellent.
You could use white cardboard and black magic marker.
Different frequencies could occupy different positions
on the disk

H^) harry  (remember- the name "plastic
scratch-o-graph"
is my trademark :^)



--- Ingo Debus <debus at cityweb.de> wrote:
> 
> Am Freitag, 28.05.04 um 10:43 Uhr schrieb Ken Stone:
> 
> > For a simple way to experiment, take a look at old
> video players. In a 
> > lot
> > of them you will find some kind of feedback
> mechanism on the capstan 
> > motor
> > or video drum motor. These sometimes take the
> physical structure of a 
> > tone
> > wheel.
> >
> 
> That's a great idea. I once ripped a video drum
> (that thing the 
> rotating heads are mounted on) apart, and it
> contained a ring shaped 
> magnet. This magnet was polarized in a way that
> there were many north- 
> and south-poles around its circumference. This would
> make a tonewheel 
> that is already magnetized, you just could use a
> coil as pickup. Hmmm, 
> there were even some coils already in it, these and
> the magnet were the 
> motor.
> 
> Ingo (imagining a tone wheel generator made of 96
> video drums)
>