21-06-2020, 09:21 PM
Thanks for the clarification Rob.
The black wires are the 6V3 heaters for the EZ81. You might have noticed that the EZ81 heaters are tied to B+ and that is because there is a maximum heater to cathode voltage allowed. (It's not shown on the circuit diagram)
This connection means that the heaters and cathode are basically sitting at the same potential so that maximum voltage won't usually be exceeded.
I would still check that there is 3v ac between ground and the green wires though, because there is always the possibility that the black and green lead out wires got swapped during manufacture.
After that, you can forget that bit of the circuit.
Eddie
The black wires are the 6V3 heaters for the EZ81. You might have noticed that the EZ81 heaters are tied to B+ and that is because there is a maximum heater to cathode voltage allowed. (It's not shown on the circuit diagram)
This connection means that the heaters and cathode are basically sitting at the same potential so that maximum voltage won't usually be exceeded.
I would still check that there is 3v ac between ground and the green wires though, because there is always the possibility that the black and green lead out wires got swapped during manufacture.
After that, you can forget that bit of the circuit.
Eddie
