Low Noise Oscillator,? can somebody help me?

Thread Starter

michael1978

Joined Jun 29, 2014
309
Hello,
Can somebody help, to understand the transistor, what does do 390pF and C(tune), and 4,3µH, they form tank circiuits? and also resistor 1K and capacitor .1, is possible somebody with little words to descirbe how it works please.....Thanks. LOWNOISEOSCILLATOR.png
 

Thread Starter

michael1978

Joined Jun 29, 2014
309
This is a classic Colpitts oscillator.

Knowing that you can find many more articles about it on the web that you will every want to readl.
For starters:

https://www.elprocus.com/colpitts-oscillator-circuit-working-and-applications/

https://www.electronics-tutorials.ws/oscillator/colpitts.html

http://www.instructables.com/id/Make-a-Colpitts-Oscillator/
I read colppits oscillator is made from 2 serie capacitor in parallel with inductor, he dont look like colppits?
 

DickCappels

Joined Aug 21, 2008
5,875
That looks about right, from memory. There are many minor variations on the Colpitts so sometimes you will see some versions that look a little strange.
 
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