RENOVATING TUNING CAPACITORS

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A valuable resource for the experimenter and home brewer, ex equipment tuning capacitors are becoming more difficult to find at the radio rallies. They usually come in 3 sizes. Above are some medium and small ones. They should never be thrown away because, unless damaged beyond repair, they are all usable with a little TLC. There are a number of ways to clean these devices but the following is the method that I use.
My thanks to G4GKA for telling me about it.

 

This a particularly poor example of a large type. It is rusty, dirty, and has solder tags and other parts screwed to it. Note also that it has a 3/8 spindle but even that problem can be overcome.
So, remove all the bits and pieces first, and check the vanes are not bent and are evenly spaced.

 

Place the capacitor in some warm soapy water. Use a scrubbing brush on the end plates, and a soft paint brush to carefully clean between the vanes. Remove any flux residues.