I have an old Truetone radio with a 10" speaker that has an open field coil. I think these field coils used to serve as a choke. So the question is should I replace the field coil with a choke or a resistor?

The schematic says the DC resistance is 1300 ohms but does not give the Henry rateing. Any suggestions?

(BTW I know I need to replace the speaker with a permanent magnet substitute)

Hi

You can use either or both in series. A modern choke will most likely have lower resistance. A resistor alone won't do as good of a job filtering hum.

If using a wire wound resistor alone you may need to increase filter cap values to remove hum.

You can use a 5-10 henry choke along with a wire wound resistor to make up 1300 ohms. This would be closest to the original in filtering and won't require additional capacity.

Norm

:I have an old Truetone radio with a 10" speaker that has an open field coil. I think these field coils used to serve as a choke. So the question is should I replace the field coil with a choke or a resistor?
:
:The schematic says the DC resistance is 1300 ohms but does not give the Henry rateing. Any suggestions?
:
:(BTW I know I need to replace the speaker with a permanent magnet substitute)