(!!!!) (Best Pair) UX-201-A RCA Radiotron Balloon NOS brass pins 1930 era (2.5ma and 3.0ma) (same Gm)
(!!!!) (Best Single) CX-301-A Cunningham NOS 1930 era (4.4ma Gm=900) (Highest mA and Gm)
(!!!!) (Best Single) CX-301-A Cunningham NOS brass pins 1930 era (4.2ma Gm=800)
(!!!!) (Recommended Single) CX-301-A Cunningham NOS brass pins 1930 era (3.8ma Gm=800)
(!!!!) (Recommended Single) CX-301-A Cunningham NOS brass pins 1930 era (3.9ma Gm=700)
(!!!) (Best Pair) CX-301A Cunningham Balloon brass pins NOS 1930 era (2.7ma and 2.8ma) 1-2% matched
(!!!) (BEST SINGLE) UX-201-A RCA Radiotron Balloon NOS 1930 era (4.2ma and Gm=900)
(!!!) CX-301-A Cunningham used/tests like new 1930 era (3.2ma Gm=800)
(!!) (BEST PAIR) UX-201-A RCA Radiotron Balloon tests like new 1930's (3.0ma and 3.4ma)
(!!) UX-201-A Radiotron Balloon used/good brass pins 1930's (2.3ma and Gm=700)
(!!) UX-201-A Radiotron Balloon used/good brass pins 1930's (2.6ma and Gm=700)
(!!) UX-201-A Radiotron Balloon used/tests like new brass pins 1930 era (4.4ma and Gm=800)
(Display tube) 201A Volutron brass base - does not work - in good condition - 1920's
01A National Union NOS 1940's (3.1ma)
01A Sylvania engraved used 1930's (2.5ma Gm=400)
01A Wards by Sylvania used/good 1940's (2.6ma Gm=700)
(!!!!) (Good Value Pair) CX-301-A Cunningham used/good 1930 era (2.2ma and 2.3ma)
UX-201-A Radiotron used/very good 1930's (2.5ma Gm=700)
(!!) (Best Single) 201A=UV-201-A Supertron Hoboken New Jersey NOS 1920's (3.8ma)
(!!!!) (BEST SINGLE) UX-201-A RCA Radiotron Balloon NOS 1930 era (4.0ma and Gm=900)