14-02-2023, 09:26 PM
(11-02-2023, 11:46 AM)Radio Fixer Wrote: I would have thought it wasnt the cap. But, if it has silicon diodes for rectifiers, you could safely tack another across the smoother and then power up and see if there is any improvement. If the rectifier is valve you shouldnt do it unless there is choke or resistor between it and the reservoir cap (there must be). Beware increasing the size of reservoir cap which may exceed the valve spec.
Actually, it would be OK to do this even with a valve rectifier. If you have a known-good reservoir capacitor of the right (or even a bit greater) value, tack it across the existing one.
It might exceed the valve's rating, especially if the existing one happens to be OK, but for just a few moments use to confirm or otherwise, you're not going to kill the rectifier. Just don't switch off and back on before the valve has cooled down, the greater capacitance value will draw a bigger gulp of charge from the still-hot cathode.
