not getting proper colpitts oscillator output

[mchak]

Hi,
I am trying to simulate one colpitts oscillator. I am using the link below.
https://en.wikipedia.org/wiki/File:NPN_Colpitts_oscillator_collector_coil.svg
I am using the software Multisim. Here i have attached the snapshot of my circuit. My question is that why i am getting the oscillator output like AM waveform??



please reply

sourav

 

[E-design]

Those values and connection looks suspect. Try the circuit below.

 

[chuckey]

That effect is called "squegging" and is normally associated with oscillators that have too much feedback, which means the very powerful RF oscillations upset the DC bias. It could be interesting to alter the value of the .1MF cap to see if it changes the squegging time constant.
Frank