(!!) 26 RCA Radiotron balloon used/good 1920's (6.2mA Gm=900)
(!!) X-226 no name balloon used/like new 1920's (6.3mA Gm=1100)
226=26 Super Silvertone Balloon used/good 1932 (4.3ma, Gm=800)
26 Coronado by RCA tests like new 1940's (6.0ma)
26 National Union engraved base tests like new 1930's (6.0ma)
26 ST-14 National Union used/65% 1950 era (3.8ma, Gm=900)
26 ST-14 Super Silvertone used/65% 1930's (3.6ma, Gm=800)
6C5G Super Silvertone engraved base used/good 1930's (6.7ma)
