[Test-Equipment] Eico 666/667 tube tester question

[Ken Kaplan]

Anyone have experience developing their own test setup for a non-documented tube for 
either of these testers? I'm writing a program to do such a task. It's almost done but I haven't 
been able to figure out why sometimes plates are connected to lever position 3 (described as 
screen or optional plate in manual) and other times to position 4 (described as plate). The 
"new tube" rules are otherwise very clear.

Thanks,
Ken