Interesting reading all the replies to this thread and good pictures.

I know of one published 432 conversion for the 6155 cavities, it was from Canada if I remember right.

I should have a  copy somewhere, it involved taking the cavity apart, which is one reason I shelved the work.  If I  remember right these were cathode driven, so the drive level necessary was higher compared to the 6154 mentioned.  I don’t remember offhand which elements of the tubes were available for bias or if it was linear, I assumed it could be made linear

All the more reason I think the time has passed on saving these, if anybody wants them for shipping costs we can talk, but shipping will be significant even for one cavity.

Gary

WA2OMY