(DISPLAY TUBE) UV-201-A Radiotron "brass base and tipped" 1920's lights up nicely but no emission (display tube)
(!!!!) (Best Pair) 201A Silvertone Balloon NOS and like new 1930 era (4.2ma and 5.0ma) (Highest mA and Gm)
(Display tube) UV-201A Radiotron brass base 1920's (does not work)
(!) UV-201-A RCA no used/good 1930 era - no printing or etching on base (2.3ma)
