The tubes are interchangeable but watch certain things. Pin #1 needs to be grounded on a 12SA7 (metal).
Both tubes have five grids (pentagrid). Heptode is mentioned when all elements are counted.
This is one case where tubes, 12SA7 & 12SA7GT, have slightly different wiring diagrams. 12SA7 uses basing "8R". Grid #5 is connected to pin #1. 12SA7GT uses basing "8AD". In this one grid #5 connects to cathode, pin #6.
Norm
:I thought these two numbered tubes were interchangeable
:until I noticed that the 12SA7 is a "heptode" and the
:12SA7GT is a "penagrid converter." I am having trouble with one of the radios I am working with that has the 12SA7. My question is:
:How will a radio be affected if one uses a 12SA7GT rather than the 12SA7? Can I use the GT in palce of the non GT?
:Thanks in advance for everyone's response,