problem with oscillator

[megadragon25]

i am trying to do a cristal clapp oscillator in multisim but i can´t finish it i need to check it with the oscilloscope but where is c4 is my output but i don't know why it does´t work

 

[IanP]

Can you post CLAP.MS10 or whatever multism file you have?

Thnx,
IanP
:wink:

 

[KJ6EAD]

You don't appear to have a valid connection between X1 and the adjustable capacitor. Your wire routing is sloppy and has unused terminals. Sometimes multisim wires can appear connected but be open circuits. Remove and replace any suspect wires.

 

[RCinFLA]

C3 (1nF) feedback is too much capacitance in relation to C2 (82 pF) feedback cap. You have killed much of feedback. Go for value in 100 pF to 220 pF range.

Be careful how much you load output.

With the large 10vdc supply, you would be better off with a resistor divider network for base bias instead of just the 220k from supply to base. 100k top, 120k bottom.

Also realize the sim may have a long startup time sequence when a high Q crystal is involved.
(up to 1 msec)