On Wednesday, November 22, 2017 at 10:22:52 AM UTC-5, bitrex wrote:

Will do. Yeah, gosh, NOS 6A8Gs are expensive! The schematic specifies
either the metal or "G" shape enclosure, I guess the GT doesn't have the
correct pinout? In any case, all the tubes currently fitted in the set
are the metal enclosure type.

The GT is fine, but it is a short tube and often the grid-cap lead will not reach the top of the tube over the shield - required for a glass-type tube. If you have no shield, stick with the metal tubes. \

It may also need an alignment, by the way. Are you equipped to do that? It is certainly simple enough - with the right tools.

Peter Wieck
Melrose Park, PA