Noise circuit

[soundman]

Hello guys,

I have found this circuit somewhere in the net, The poster there told that this circuit can be use as an noise generator. What do you think about the circuit? which kind of noise it will generate, and at which freq?

Thanks.

 

[audioguru]

A zener diode makes white noise up to about 2MHz. The transistor amplifies it up to a frequency determined by the transistor.
The coupling capacitor's value cuts low frequency noise from the zener diode depending on the input resistance of the transistor circuit.

 

[soundman]

Thanks for the reply,

Which value for the Zener diode is suitable here? Do I need to add another stuff to this to generate noise or it is the whole?

 

[cowana]

I'd use something like a 5v6 zener.