Don Bowey wrote:

I think it might be one of them furrin tubes from before the
standardized letter/number numbering system.

-Chuck
It's a octal base, pentode RF amp. The suggested replacement is a 1N5GT.
Any idea who made it? My RCA data books cover the era when it must have been
made, but have no listing.

-Chuck

I got the tube info from my old Sylvania tube manual. It was up-to-date
through mid-55. The tube was listed in the condensed section, so it was
obsolete at the time it was printed. Don't know who all made it.

The 1N5GT was fully documented, so it was somewhat modern at the time.

My RCA books have the 1N5GT well documented, as you say, but nothing on the
1SA6. They must not have thought it worth stealing. What do you suppose is
the 6th element in the 1SA6?

-Chuck