Replacing Mica caps with film or ceramic?

[Electronic M]

Modern NP0 ceramics are often as good as tube era micas. The big issue issue with ceramics is thermal drift and NP0 are usually stable. For caps 1000pF and higher use film. Look at the capacitance tolerance of the original part and get one with the same or lower tolerance.

Avoid changing tuner/IF micas unless there is significant leakage current.