Field coil is normally used as a filter choke in a power supply. You can use a modern PM type speaker and replace the field with a 10 henry choke. May need to add some series resistance it voltage is too high for the 6L6's?
Norm
:Hi I do have a question I just picked up a 125 watt tube amp chassis with 2 6L6 and a 5Z3 with I think is a rectifier tube anyway I do know that it works but I have no speaker for this unit my question is how can I determine what kind of field coil I need for this I have found that just wiring the speaker in wont work I guess it dose need a field coil speaker
:thanks Angelo