Historical notes about development of tubes from early years to our days in the World and in Russia

Vitaly Brousnikin, vitalybr@onego.ru

http://oldradio.onego.ru/ 

For a time receiving and amplifying valves were named in this country "cathode" or "vacuum relay". The first Russian mass valve designed in 1918 at the Radio Laboratory of the town of Nizhny Novgorod under supervision of M.A.Bonch-Brouyevich (on the basis of the first model - "Babushka" tube) was named PR-1 ("vacuum relay, model no.1"). The name of the R-5 valve produced in 1922 by the Petrograd Electro-Vacuum Works meant: "relay, model no.5. A new valve with thoriated cathode produced in 1923 consuming a ten times less

PR-1

denominated K2-T ("rectifier with two anodes and thoriated cathode").

By 1929 the number of models of radio valves increased very much, which caused the necessity of the introduction of a new integral system of their

1. R5

2. Micro

3. MDS

denomination. A 'letter and figure' system of marking was introduced, which remained till early 1940's. The first letter in the valve marking shows

heating current than the "R-5", was named the "Micro". Equally economical of heating a two-grid valve with "cathode grid" was named "MDS" ("micro, two-grid").The first low-powered vacuum rectifier was

it's category: "P" - receiving, "U" - amplifying, "S" - special, "V" - rectifying, "T" - broadcasting, "N" - low-frequency. The second letter described the cathode - "T" - thoriated, "K" - carbonized, "B" - bariated, "O" - oxide. The figure included

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