astable multivibrator to superregen

[mstechca]

The URL: **broken link removed** states:

In general, any standard oscillator circuit can be used as a Regen receiving circuit by backing off the feedback so that the oscillator just stops oscillating; at this point it acts as a high gain, narrow bandwidth Bandpass Filter resonating at the frequency you've tuned it to with the main tuning capacitor.

so what I want to do is take a standard 2-transistor astable multivibrator (you can find it at 4QDTEC's website, and a zillion of others) and convert it into a superregenerative detector. Who can show me how this is done? or do you believe that the above URL is giving false information?

 

[Wrighty]

Yes, any resonating circuit (such as a oscillator) will act as as a band pass filter. Depending on the resonant frequency you have set the circuit to using the tuning capacitor. Remember the formulae for resonant frequency is 1/2PIE x (rootLC).

 

[Wrighty]

sorry computer just packed up. what do you need this circuit for?

 

[audioguru]

It is a tuned radio-frequency Colipitts oscillator, not a simple audio-frequency multivibrator.

Since this circuit is a regen receiver and not a quenched-at-30KHz super-regen, it acts as a "narrow bandwidth Bandpass Filter".

The author shows a do-it-yourself audio amplifier too that has proper biasing, negative feedback and idle current through its output transistors.