7jp4 bk 440 testing

[timmy]

Even putting the heater wires together as one wire and then the cathode wire shouldn't or would it hurt the heater?

[Kevin Kuehn]

It could if the cathode is shorted to the heater at some point in between the two heater pins. In which case you'd still be putting a high voltage across a section of the heater element. Although I'm not familiar with the internal element layout of that tube.