[sdiy] Tonewheel questions

[Ken Stone]

>> For a simple way to experiment, take a look at old video players. 
>
>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.

Actually some of these motors have a cassette player head pointed directly
at the magnet for exactly this reason. Some use PCB "coils", and some use a
metal toothed disk and a coil. I'd suggest the older the VCR the more likely
for it to use the metal disk.

Ken 
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
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