7247 GE NOS tall gray ribbed plates 1970”s (1.1ma and 9.4ma)

1 tube) 7247 GE NOS tall gray ribbed plates 1970”s

12AX7 Section = 1.1ma Gm=1600

12AU7 Section = 9.4ma Gm=2100

Tested on Amplitrex

12AX7 Section Good = 1-1.2ma Gm=1600

12AU7 Section Good = 8-10ma Gm=1800-2200