03-12-2014, 07:15 AM
The voltage spike on warmup is typical of any radio with a filament type rectifier and remaining tubes of the heater cathode type.
I normally use 500V rated electrolytics, especially for the first cap after the rectifier. You are probably ok with the 450V rated ones as they usually have a higher short term "surge" rating, but if you can find higher rated ones its preferable.
I have tested 450V rated caps on a tester at up to 550V or so on a cap leakage tester and they seem ok, but you definitely don't want to expose them to overvoltage for long periods.
I normally use 500V rated electrolytics, especially for the first cap after the rectifier. You are probably ok with the 450V rated ones as they usually have a higher short term "surge" rating, but if you can find higher rated ones its preferable.
I have tested 450V rated caps on a tester at up to 550V or so on a cap leakage tester and they seem ok, but you definitely don't want to expose them to overvoltage for long periods.