Colpitts oscillator

163

02:42:44

An attempt at this circuit. Not very stable output, supposed to be 50 MHz but goes up and down a few points. 

published 8 years ago

hurz

8 years ago

With 300mH coil its factor 1000 to slow for 50MHz!

eekee

8 years ago

I ran this at over 90MHz easily, but couldn't make it any more stable. In fact, I couldn't keep it running at all. The output would diminish and spikes appeared until, below 10mV, the spikes wrecked the oscillation. This slow version seems more interesting because it will keep running with a tiny output; 266μVp-p.

eekee

8 years ago

Err never mind. Put a switch in the power line of this one and you get the same large but diminishing output I got. If it starts with several volts amplitude, it's not much use if it stabilizes 40,000 times smaller.

hurz

8 years ago

@eekee, are you kiding, you run it at 90MHz without any change?

hurz

8 years ago

As i already said, to run it at 50MHz it needs some changes, most importante is a feedback which is in the original completely missing and tune the values. 300mH is a million times to high for an proper oscillator. check this http://everycircuit.com/circuit/6240192297172992

eekee

8 years ago

@hurz: I made a lot of changes, none of which did any good. Thanks for your fixed copy.

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