On Monday, April 15, 2002 at 4:56:13 AM UTC-7, Jan Wemmel wrote:

Even that I have been trained as a Radio and Television Technician in
Germany (admittedly 10years ago) and that I have a degree in IT and
Telecommunication, I have never seen a diode with varistor characteristics.

Diodes with specifications that make them suitable for temperature compensation
of power amplifiers are marketed as 'compensating diode', 'varistor',
or 'stabistor', and I wouldn't be surprised to see 'thermistor' as well.
Telephone company 'varistor' units are antiparallel diode pairs.

If you have a working unit, and a multimeter with 'diode check' feature,
any another diode with the same forward voltage will be a good replacement.