05-10-2020, 08:29 PM
Steve
Thanks for the explanation of why the resistor was changed from 15k to 10 k. I did see the change in a service bulletin but I didn't want to make the change without knowing why it was made.
Morzh
Plate voltages were taken to the chassis and to the cathode and there is not much difference between them.
You mentioned the lower input impedance of the older test equipment and that caused a Homer Simpson "Doh" moment. I put a 229 kOhm resistor across the input of my meter and the measured voltages were still high, but only exceeded the maximum allowable plate voltage by 4 to 7 volts, much better. I'm still concerned that this may be an issue when this radio is plugged into the wall receptacle where the line voltage will run the plate voltage back up to 275 volts or so.
Thanks for the explanation of why the resistor was changed from 15k to 10 k. I did see the change in a service bulletin but I didn't want to make the change without knowing why it was made.
Morzh
Plate voltages were taken to the chassis and to the cathode and there is not much difference between them.
You mentioned the lower input impedance of the older test equipment and that caused a Homer Simpson "Doh" moment. I put a 229 kOhm resistor across the input of my meter and the measured voltages were still high, but only exceeded the maximum allowable plate voltage by 4 to 7 volts, much better. I'm still concerned that this may be an issue when this radio is plugged into the wall receptacle where the line voltage will run the plate voltage back up to 275 volts or so.
Sometimes I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it.