12-28-2017, 10:01 AM
Terry:
The 120 Hz hum rises and falls in volume with the volume control. When turned all the way down, it is inaudible.
If you were suspecting the field coil, I measured it with an Ohmmeter yesterday at it came in around 1040 Ohms -- close enough to the 1100 Ohm value specified in the schematic. The 6.5 kOhm ESR value at 120 Hz is much higher due to the field coil's high inductance at that frequency.
Bob:
Thank you. I am very happy to find and join such an active community of Philco radio enthusiasts!
--
Jason
The 120 Hz hum rises and falls in volume with the volume control. When turned all the way down, it is inaudible.
If you were suspecting the field coil, I measured it with an Ohmmeter yesterday at it came in around 1040 Ohms -- close enough to the 1100 Ohm value specified in the schematic. The 6.5 kOhm ESR value at 120 Hz is much higher due to the field coil's high inductance at that frequency.
Bob:
Thank you. I am very happy to find and join such an active community of Philco radio enthusiasts!
--
Jason
