In this section is given a first survey of special vacuum tubes used to measure physical
phaenomena. There are sensors and transducers, as well as tubes used in signal conditioning, as
voltage references and amplifiers. Also some counters and displays, used in the early digital
instruments, are illustrated. And, since many precision equipment depend upon an accurate
frequency reference, some quartz crystals and tuning forks are also shown.
I hope to expand this section in the future.
18503 Philips, a radiation counter tube; mica window.
571-K2471-304 Varian is a high-vacuum Bayard-Alpert type ion gauge.
5734 RCA was a mechanical displacement transducer, proposed as active phono pick-up.
5800 Victoreen, electrometer tetrode.
5803 electrometer triode.
5889 is an electrometer pentode with grid out from the top and guard ring; 7.5mA filament at 1.25V.
5980 is a gamma counter tube.
5845 was a double diode noise generator.
5962 Corotron corona voltage regulator; 700V, 5 to 55 microamps.
6119 subminiature corona voltage regulator; 2.1KV.
6213 subminiature voltage regulator; 130V, 1 to 2.5mA.
631P1 Strobotron, cold cathode flash tube.
6438 subminiature voltage regulator; 1200V, 5 to 100 microamps.
6700 trochotron decade counter; 2MHz max. The tube is surrounded by a magnetic shield.
6701 decade counter; similar to 6700 with 1MHz max counting frequency.
6701 variant. Burroughs made some variants to the external finish.
6703, similar to 6700.
6909 beam-switching bidirectional decade tube; 100Kpps max.
6923 RF diode for test probes. Similar to EA52.
B5441 Nixie display tube from Burroughs.
B5560 Nixie indicator from Burroughs.
B5870ST is a PCB version of Nixie dispaly.
B5991 front view variant of Nixie.
C-F2518001 thermocouple vacuum gauge.
CV220 stroboscopic flash tube.
D-79510 Western Electric was a vacuum ion gauge, derived from the 205B triode.
GC10/BS dekatron beam-switching counter.
GRD7 current limited diode with guard rings.
GV4S-1600 subminiature corona voltage regulator; 1600V.
501-7736 thermocouple vacuum sensor.
7427 cadmium-sulphide photocell.
GV6A-1300A corona voltage regulator, 1600V
GV6A-700 corona voltage regulator, 700V
GV9A-2800 corona voltage regulator, 1800V
TT-15 Chronotron, from Bendix.
Demo Tubes for Physics Laboratories
Top: BR2, Brown demonstration CRT for Physics Laboratories. Manufactured by Narva.
Bottom: the same electron gun is used to make the small propeller to rotate in this
Narva SKR2, a
demo electron flow windmill.
Precision quartz crystal resonators were usually vacuum sealed to increase Q. Here some units of
crystals and one tuning fork resonator.
More Regulator Tubes
Here are some additional voltage regulators, used through the years inside instrumentation or high
stability communication equipment.