Are there other circuits or components you can use to simulate the functionality of a variable capacitor? I’m looking at some circuits that require them and all I can find on ebay is vintage units from crystal radios costing as much as $25 a piece? Can they be replicated or am I stuck having to buy these?
Can you use a diode?
Plastic variable capacitors as used in cheap transistor radios are readily available. Or, buy a radio and remove the capacitor.
Leon
What are you trying to do? What range do you need? Trimmer caps are readily available.
Thanks for the responses guys… I think I’m getting closer to understanding this. the circuits I’m looking at are mainly RF receive/transmit circuits. (one is for a shortwave loop antenna, the other is an FM transmitter) When I search for “radio” and “variable capacitor” all I get are the old, antique style bladed kind.
It sounds like the cheap, trimmer-types will work, as long as they are near the correct range that the circuit calls for? am I understanding this correctly?