6N7 Tube QRP Power Amplifier - One Rainy Day DIY Project

Once upon a time I'd decided to join a Big Guns Gang and made a Super-Duper Powerful Vacuum Tube QRP amplifier for my 800mW QRPP homebrew telegraph vacuum tube transceiver "3T" (I promise to write a separate article or two about this three tube transceiver project later). It was not an easy decision to me because for that legendary time I'd...

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6P3 (6П3) Beam Power Tetrode

6L6 vacuum tube has been introduced by Radio Corporation of America in July 1936 and since 1937 it began to be produced in the USSR on equipment provided by RCA. For the first time it was usual metal 6L6 , but later was chosen glass bulb design in order to avoid overheating, so just before the WWII tube factories started to produce 6P3 (6П3)...

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6P7S (6П7С) Sweep Tube

6P7S (6П7С) TV sweep tubes, as their western sisters 6BG6 was used as a horizontal driver in some early black'n'white TV sets. In fact, this tube is not a direct 6BG6 clone, it is an octal modification of G-807 tube, which one was soviet clone of famous 807.Interesting, that both 6P7S and 6BG6 tubes has the same pinout and nearly the same...

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GK-71 (ГК-71) Power Pentode

GK-71 (ГК-71) is a somewhat similar (but not the same) to the famous 813 by RCA. There was another soviet replica of RCA 813 - GU-13.GK-71 (ГК-71) has a narrower frequency range and a slightly less gain than, say, GU-13 tube, but there are some advantages - it was dirt-cheap and has a terrific endurance (resultant of massive graphite anode...

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GU-50 (ГУ-50) Power Pentode

GU-50 (ГУ-50, folklore HAM name "poltinnik" meant "half-a-buc") was an universal, most common xUSSR power tube from the 50's up to the present days. It could be found in an every technical shop everywhere and was so inexpensive, in an usual TV-set's tubes price range.So funny, but sockets for those halfbucs was so rare and priced much more....

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