Hello, so I have to do a voltage controlled audiofrequency oscillator. I did the basic schematic but now I am having trouble controlling the frequency with a voltage ( as stated in the requirements ) . So I need somewhere to start as I found nothing on the internet. Thanks !

 

Use an LM566 chip .

 

Use an LM566 chip .

I can't use any integrated circuits or varicap diodes or amp ops, only R, C and bipolars

 

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Use a JFET for the R component in the phase shift network.

Or possibly this -

http://www.analog.com/media/en/technical-documentation/application-notes/AN-112.pdf

https://www.maximintegrated.com/en/app-notes/index.mvp/id/3846


Regards, Dana.