(!!!!) 56 Arcturus Blue Balloon engraved base tests like new 1930's (5.0ma)
(!!!) (BEST PAIR #2) 47 RCA branded ARCTURUS NOS 1940's (34.5ma and 35.2ma)
(!!!) (BEST PAIR #3) 47 RCA branded ARCTURUS NOS 1940's (40ma and 40.2ma)
(!) 203A Sylvania brass base tests like new 1930's
(!) 247=47 RCA Balloon used/60-65% 1930's (20ma)
(!) 247=47 Tungsol Balloon used/good 1930's (23.2ma)
(!) 47 RCA Radiotron Balloon used/good 1930's (23.4ma)
(!) 47 RCA Radiotron engraved base used/good 1930's (27.5ma Gm=2250)
(!) NY-247=47 National Union Balloon used/good 1930's (22.6ma) (and strong Gm)
(!) RY-247=47 Federal Supreme Balloon used/good 1930's (24.2ma)
56 RCA Balloon engraved base black plate tests like new 1930's (4.7ma)
