(!!) (Best Single) 201A=UV-201-A Supertron Hoboken New Jersey NOS 1920's (3.8ma)
(!) (Best Single) UV-201-A Radiotron tests like new 1920's some scrapes on base (3.8ma)
(Display tube) 201A Volutron brass base - does not work - in good condition - 1920's
(DISPLAY TUBE) UV-201-A Radiotron "brass base and tipped" 1920's (does not work - display tube)
01A Sylvania engraved used 1930's (2.5ma Gm=400)
01A Wards by Sylvania used/good 1940's (2.6ma Gm=700)
UV-202 Radiotron "brass base" and tipped NOS original box 1920 era (45ma) (very rare)