Steve Kavanagh wrote:
A year or so ago I was working on a microwave local oscillator (at
about 2.5 GHz) multiplied up from a crystal oscillator near 40 MHz.
The output was found to jump in frequency by tens or hundreds of Hz
many times as the LO chain was warming up. I was able to reduce this

Steve, I've had several silver micas go weird in 20 odd year old Racal
radios that I've fixed, they're second only to Tantalum caps as a cause
of faults in those. But at least they don't explode!

Regards
Dan
AC6AO G3NCR