10-28-2020, 08:31 PM
What a crazy design. Two field coils in the power supply, and another that’s tapped and used as a voltage divider.
The Schematic shows that the field coil from the tap to chassis is 3700 ohms. So in theory you can make a voltage divider out of 3700 and 2400 resistors, or a combination of available values to get you close. Then you could use a PM Speaker.
A speaker field with an approximate DC resistance of 2400 and a 3700 ohm resistor could possibly work, but as previously mentioned, there may not be enough current. Using the difference in voltages between the plate and screen of the 58 RF tube you could calculate the current through the 2400 ohm section. If I did it right, that would be 28-33 Ma. Hard to say if This would work on a different speaker.
Just a thought.
The Schematic shows that the field coil from the tap to chassis is 3700 ohms. So in theory you can make a voltage divider out of 3700 and 2400 resistors, or a combination of available values to get you close. Then you could use a PM Speaker.
A speaker field with an approximate DC resistance of 2400 and a 3700 ohm resistor could possibly work, but as previously mentioned, there may not be enough current. Using the difference in voltages between the plate and screen of the 58 RF tube you could calculate the current through the 2400 ohm section. If I did it right, that would be 28-33 Ma. Hard to say if This would work on a different speaker.
Just a thought.
Tony
“People may not remember how fast you did a job, but they will remember how well you did it”
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