19-03-2019, 10:18 PM
That is typical of the uninformed.
They were looking for a 13 amp fuse just to make sure that there wasn't any more smoke in it.
The UL41 is not the easiest valve to test as the heater is 45 volts.
If it were a valve with a 6 volt heater you can warm it up with a slightly under run heater from a USB charger and test it with a diode tester. That is how the life test works on a TV tube tester works.
The rectifier valve will have taken a hit too.
The dropper resistor will almost certainly gone open circuit in addition to the output transformer.
The heated capacitor is the clue leading me to the dropper resistor.
They have turned an easy restore into a challenge.
You could do with an isolating transformer for working on live chassis sets.
They were looking for a 13 amp fuse just to make sure that there wasn't any more smoke in it.
The UL41 is not the easiest valve to test as the heater is 45 volts.
If it were a valve with a 6 volt heater you can warm it up with a slightly under run heater from a USB charger and test it with a diode tester. That is how the life test works on a TV tube tester works.
The rectifier valve will have taken a hit too.
The dropper resistor will almost certainly gone open circuit in addition to the output transformer.
The heated capacitor is the clue leading me to the dropper resistor.
They have turned an easy restore into a challenge.
You could do with an isolating transformer for working on live chassis sets.
