2NAX7? solidstate replacement curiousity

[tim]

Hey all....I just picked up a bunch of surplus electronic parts a week or so back and was going through the stuff tonight. I found a little can about the size of a 12AX7, curiously heavy for it's size, that was marked 2nax7 made in the USA by a company called Paratewb. I stuck it in a HRDx I have as a test platform and it seems to work just like a 12ax7 (duh). I couldn't turn amp up as it's too late at night and don't want to wake up the neighborhood....can anyone shed any light as to it's pedigree? No info on Google that I could find.
Thanks,
Tim

[drewl]

Hmmm, interesting....metal preamp for heavy duty or military apps?
I know when I used to work on test equipment back in the 80's, Tektronix had some hybrid scopes that used early ss devices that plugged into sockets similiar to the earlier tube oscilloscopes.