Ringmodulated questions

[mark verbos]

Grant Richter wrote:
> 
> >
> >1) What sizes are the transformers supposed to be? My nearest parts
> >supplier no longer has these kinds of small transformers in stock
> >(They had a year ago...Boohoo), and they don't want to order unless
> >they *know* that is what I want, or something like that. So, anyone
> >has any useful trransformer data to give me? "It ought to be in the
> >range...", kind of?
> 
> This is the first electronic music circuit I built. The original voice scrambler.
> The transformers are 10K:10K interstage coupling transformers. As I
> recall one side must be centertapped.
> 
> >2) This one is more out of curiosity: Why germanium? As you can see
> >from these questions, I'm no electronics wiz: I like to make noises,
> >and to make boxe that makes noises, but the design part of it is black
> >magic to me...Anyone got a "Noisebox circuit design for the
> >electronically impaired" book to recommend? :-)
> >
> 
> Because the circuit has no active elements, the audible threshhold
> is set by the diode conduction voltage. Silicon begins to conduct
> at say 700 millivolts. Germanium begins to conduct at 200 millivolts.
> That's a much lower voltage that you can start to get a signal out.
> You can use 1N34 or 1N34A if they still make them.
> 
> Bear in mind this circuit wants to see like 10 volt peak to peak signals.
> Not the output of your cassette player.

or the output of a Waldeck oscillator.

mark