(!!) UX-201-A Radiotron used/good 1930's (2.3ma and Gm=700)
(!!) UX-201-A Radiotron used/good brass pins 1930's (2.5ma and Gm=700)
(!!) UX-201-A Radiotron used/tests like new brass pins 1930's (3.5ma and Gm=800)
(!) M-201A Macy balloon 1929 used/strong (2.7ma)
(!) UX201-A RCA balloon used/good, brass pins 1920's (2.0ma)
(!) X-201-A Bond balloon used/tests like new 1920's (3.0ma)
(#1 01A PAIR) 01A NOS USA MADE 1930's (4.1ma and 4.0ma) matched on Amplitrex
(Display tube) 201A Volutron brass base - does not work - in good condition - 1920's
(picture only) 01A RCA engraved base NOS 1930's
01A National Union NOS 1940's (3.1ma)
01A PHILCO engraved base used/tests like new 1930's (3.7ma)
01A Sylvania engraved used 1930's (2.5ma Gm=400)
CX-301-A Radiotron used/very good 1930's (2.5ma Gm=700)
UX-201-A RCA Radiotron used/very good 1930's (4.2ma Gm=800)
