RV12P2000
The RV12P2000 electron tube is a universal pentode from a military development, which was brought onto the market in 1937 and had the smallest possible dimensions at that time: the piston diameter is approx. 24 mm, the height of the base including the grille cap approx. 44 mm.
Type designation
The Wehrmacht used its own key to designate the tube types. The R stands for army tube, the V for (voltage) amplifier, and the 12 indicates the (average) heating voltage in volts . The number 2000 stands for the theoretically maximum gain that can be achieved. The 12.6 V was chosen because most vehicle electrical systems ( alternator / starter , starter battery , ignition system, etc.) were designed for it. The required anode voltage was usually generated using a single armature converter .
development
The development of the electron tube in the 1930s had so far not produced any types that could be used in the radio frequency ranges used by the military up to approx. 300 M Hz and at the same time had a small installation size and mechanical robustness for portable use. This gap should be filled with the tube, often referred to as P2000 for short .
The development of the P2000 began in 1933 in the receiver laboratory of the Telefunken Society in Berlin-Schöneberg. Walter Graffunder was appointed project manager , the development itself was carried out by Werner Kleen and Horst Rothe . This preliminary work resulted in the types SF1 and SF1A. The latter already had the characteristics of the P2000 and only differed in the heating data and the maximum anode power loss.
A fundamental innovation in the development of these types of tubes is the use of a pressed glass plate for the connection bushings , which replaced the conventional, high-frequency problematic pinch-foot design. The electrode connections could be kept shorter, which reduced the disruptive capacitances .
P2001
Later the RV12P2001 was developed, which, in contrast to the P2000, has a grid voltage-dependent slope and thus a control characteristic due to the special construction of its control grid (unequal spacing of the grid wires) . This enables the gain to be changed via a variable bias .
The type designation is a compromise because a distinction had to be made between the "normal" and the regular version, but the tubes were identical except for the control grid.
post war period
In the post-war period , the large numbers of Wehrmacht transmitters and receivers were cannibalized and the P2000 used in civilian radio receivers. The Heinzelmann radio construction kit , which founded the success of Grundig AG , also used the P2000.
The Telefunken -Werk in Ulm presented in 1948 already back P2000 appreciable scope, in order to satisfy the high demand from trade and industry.
The VEB tube factory " Anna Seghers " in Neuhaus am Rennweg (formerly Telefunken) manufactured the P2000 until the 1960s.
The EF95 can be seen as the successor to the P2000.
- P2000 and socket
P2000 in socket
P2000 with socket and pull button
P2000 in the "Würzburg" radar unit
literature
- Ludwig Ratheiser: The great tube manual . Franzis-Verlag, Munich 1995, ISBN 3-7723-5064-X .
- Gerhard B. Salzmann: On the history of the RV12P2000 . Rüdiger Walz, Kelkheim 1994, ISBN 3-9802576-2-2 .
- Data sheet P2000 as PDF, 360 kB
- Data sheet P2001 as PDF, 272 kB
swell
- ↑ P2000 in the Radio Museum
- ↑ Explanations of the Wehrmacht tube key ( memento of the original from June 25, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Funk-Technik anthology 1948
- ↑ History of EF95
