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ID = 29213
United States of America (USA)
Brand: RCA (RCA Victor Co. Inc.); New York (NY)
Developer: General Electric for Brand RCA-Radiotron; Bridgeport CT, Syracuse NY 
Tube type:  Voltage Regulator, single   Power-supply 
Identical to UX874 = 38274 = SE-3918 = CV643 = CX374
Similar Tubes
Other shape (e.g. bulb type):
Normally replaceable-slightly different:
  PT-874 ; R_Raytheon

Base UX-Base (4 Pins (2 thick, USA 1924, UX)
Was used by Radio/TV-reception etc.

Late in 1924 experiments began at the Westinghouse laboratories on designing a neon gas voltage regulator tube. Work started on development of this tube in March 1925. the tube became available in the following year but it was plagued with difficulties. Research into these problems was transferred to the GE laboratories in March 1927. It was not used in any great extent commercially. The cylinder element was connected to one base filament pin and the other element was connected to the grid pin. With this connection, the battery eliminator cannot be turned on until the tube is inserted in the socket. The tube was originally designed for use with the RCA type 104 amplified speaker.

Voltage regulator 90 Volt (ignition 125 V), 10 - 50 mA,

Dimensions (WHD)
incl. pins / tip
x 137 x 54 mm / x 5.39 x 2.13 inch
Weight 69 g / 2.43 oz
Information source - - Manufacturers Literature   Early Tube Development at GE 1929

UX874: Mfg. data sheet
Jay Kinnard

Just Qvigstad
UX874: own collection
Peter den Boer

More ...
Usage in Models 2= 1925 ; 1= 1926 ; 1= 1927? ; 3= 1927 ; 2= 1929?

Quantity of Models at with this tube (valve, valves, valvola, valvole, válvula, lampe):9

Collection of



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