RCA Type 913 One Inch CRT

RCA 913 CRT With Box
RCA released the type 913 CRT in 1936.  It had a one inch diameter screen and, from the side, could easily be mistaken for a 6L6 tube.  It was a low cost alternative to the more expensive, larger CRT's (such as the 906) and was meant for the amateur and experimenter market.  It sold for about $4.00  when it was released (at about 25% of the cost of a 3-inch tube), but by the 1950's, because of limited demand, it was actually more expensive than a 3-inch tube.