Film Variable Capacitors
Structural film variable capacitors add a plastic film as a medium between the moving piece and the stator, and the shell is encapsulated by transparent or translucent plastic, so it is also called sealed single-connection or sealed double-connected and sealed four-connected variable capacitors.
Advantages Small size and light weight. Disadvantages are loud noise and easy to wear.
Purpose Single connection is mainly used in simple radios or electronic instruments; double connection is used in transistor radios and electronic instruments and electronic equipment; quadruple connection is commonly used in AF/FM multi-band radios.