Hartley oscillator: amplitude not stable

Thread Starter

patpin

Joined Sep 15, 2012
401
Your main goal is to get the right frequency.This you can do by picking up the right amount of capacitor.For example, placing several capacitors in parallel or using a tuning capacitor.Although I do not understand why you need this frequency.My circuit is not critical to the frequency.
Indeed I do not need a specific freq. But since you wrote about 'resonance freq' I asked myself how to achieve it. Now I know: with a trimming cap. And checking which parameter while trimming?
 

Bordodynov

Joined May 20, 2015
3,179
Then you do not need to think about adjusting. What the frequency turns out, so be it. Capacitor take 750 pF. Wind on that ferrite rod, which I advised you, 70 - 75 turns. It is better to use a special wire, which I advised. Unfortunately, I can not tell you the type of that stranded wire. Maybe everything will work with the usual wire. It may be necessary to increase the value of the resistor in the collector of the transistor.
 

Thread Starter

patpin

Joined Sep 15, 2012
401
Then you do not need to think about adjusting. What the frequency turns out, so be it. Capacitor take 750 pF. Wind on that ferrite rod, which I advised you, 70 - 75 turns. It is better to use a special wire, which I advised. Unfortunately, I can not tell you the type of that stranded wire. Maybe everything will work with the usual wire. It may be necessary to increase the value of the resistor in the collector of the transistor.
Many thanks to Bordonynov and others!
 
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