02-23-2020, 01:59 AM
Don't think I've ever seen a metal standard based tube, only on the self centering tubes (octals). Pin 1 is always the heater. Have seen some tubes that have had a sprayed on coating but I don't remember if it has any connection to anything.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry