[Chas]

Radios that have had metal/glass swaps require a bit of care during a triage. Not all metal tubes can "play" in a respective socket. A "Glass Only" socket may have pin #1 re-assigned to a B+ dropping resistor or some other "shocking" connection.

I got that as a painful lesson servicing a set at 12yo., gave myself a life-long rule, glass into glass and metal into metal, never mix the two... chas