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VGT128

Sensibly equivalent to:
CV1128 GT1C NGT2
See also:
The World's First Computer - Gas Clean-up in Xenon Thyratrons
    
Extras ▼

 

The VGT128 argon filled thyratron is from the 1930s and was used in timebases etc. This valve was made for the Government controlled General Post Office that ran the telephone system and various government communications.
The worlds first computer, Colossus, used these thyratrons as pulse generators. The operating speed of Colossus was 5,000 cycles per second.
The commercial GT1C Type designation contained within the M-OV ellipse.
The shielded anode and trigger electrodes at the base of the image with the heater and cathode at the top.
The GPO and VT189 are etched into the envelope.
The classic envelope is 44 mm in diameter, and excluding the B5 base pins, is 101 mm tall.
References: Data-sheet, 1040 & 1043. Type VGT128 was first introduced in 1937. See also 1937 adverts.

 

Pin Connections
B5
1
2
3
4
5
a
g1
h
h
k

 

Absolute Maximum Operating Conditions
The Thyratron
Vh
Ah
Va
mAa
4.0
1.35
500
1000
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated July 23, 2019.
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