hi every one again
I'm making a spy circuit from talking electronics
problem is that it needs a 2-10 pf trimmer but to keep costs down im thinking about using a 3-11 pf trimmer only 23 pence each
will the difference make the circuit different or will it be OK to use
cheers
marko

 

The purpose of the trimmer capacitor is to be able to manually tune the circuit to the required frequency. Once it is set, one would hope the trimmer is about somewhere in the middle of its capacitance range. 3-11pF will work just as well as the 2-10pF trimmer. You are actually adding to the 39pF. That itself could be way off its nominal value to put you out of the desired frequency range.