Variable capacitors were used in radio receivers to tune into radio stations.As a rule, an inductor was connected to the capacitor, and by changing the capacitance of the capacitor, we changed the frequency.Today you can find a capacitor, as in this article, in the radios of the 90s and early 2000s, but not in all, because instead of a capacitor, could use an electronic tuning with varicaps or a frequency synthesizer.
In this article, I will briefly talk about connecting a multi-output variable capacitor and disassemble it to see how it works
There are six pins in this capacitor.The pin in the middle is the common pin for all four variable capacitors, that’s how much this part contains.Two variable capacitors with a capacity from 10 to 140 pF and two with a capacity from 10 to 30 pF.There are also four trimmer variable capacitors, they serve to adjust the capacitance of variable capacitors.
How to check and how to find out the capacity of four variable capacitors? To do this, connect the radio parts tester and, by changing the setting knob, monitor the minimum and maximum capacity.
This is a tuning of the trimmer capacitor
And what’s inside?
You will see the stator and the rotor of the capacitor and between them the insulation in the form of film
Video of checking the variable capacitor and its disassembly
