Vacuum Tubes I Have Known - Part 5

Vacuum Tubes I Have Known – Part 5 304TL—A WW2 Triode consisting of 4 type 75TL triodes in a common envelope. GL-446 – A WW2 planar triode used in radar receivers, also known as a “lighthouse tube”. The NuVistor – A series of tubes designed by RCA to compete with the rather new Transistor. Rather short lived, these were the last gasp of the vacuum tube. A 6CW4 (triode) and a 7587 (tetrode) are featured. Vacuum Tubes I Have Known – Part 4 813 – A beam power tube that was introduced in 1938 and became well known in WWII and remained very popular with amateur radio operators following WW II. The latest tubes manufactured by RCA and Amperex featured an improved plate made of zirconium-coated nickel. 7242 – A triode having a plate dissipation of over 100 watts. Now (if) used, it is in DIY audio amplifiers. Time Delay Relay – Made by Amperite these thermally operated time delay relays were often used to delay or sequence start-up of vacuum tube circuits. Vacuum Tubes I have Known – Part 3 6199 – A ten-stage, end-on, Photomultiplier, in this case with an added-on Picker sample holder This means it was designed, with the now integral holder, for radioactivity, rather than visible light measurement. 8072 – A ceramic, beam power tube for RF power amplification. Vacuum Tubes I have Known – Part 2 6J6 – A common Cathode, Dual Triode with an indirectly heated cathode usable to 300 Mcs. 2CX250B – A Power Beam tetrode used in 100-300-watt VHF-UHF transmitters. Introduced in 1960. Vacuum Tubes I have Known – Part 1 4B26 – Diode with a direct heated Cathode and Mercury (Low Pressure) Fill designed for 6-amp battery charging. 955 – An Acorn enclosed triode developed for high frequency work.