CONFIDENTIAL
October 19, 1942
Officer in Charge
Naval Ordnance Laboratory
Washington Naval Yard
Washington, D. C.
Attention: Mr. L. R. O'Neill
Dear Sir:
In accordance with the request of your Mr. R. C. Green by long distance telephone on Saturday, October 17, 1942, we are shipping tomorrow by parcel post, four miniature thyratrons developed by the NCR Company for special research use and four miniature thyratrons made by Hygrade Sylvania Corporation under our direction.
The NCR type tube has approximately the following characteristics:
- Heater - 3.2 volts AC
- .6 amperes
- 1.9 watts
- Plate votage = +125 volts
- Grid ignition mº = -12.5 volts
- Grid current (tube conducting) = 150 µ amp
- (with -100 volts applied through 1/2 meg resistor)
- Maximum anode current = 25 ma
- Anode-cathode drop = 16 volts
- Grid-anode test breakdown voltage = 400 volts
- Cgp = 1.3 µµfd
- Cgk = 3.5 µµfd
- Cpk = 1.6 µµfd
- Base = bakelite, plugs into amphenol tpe 848
- Envelope = glass, 2-7/32 long by 25/32" diameter
The Sylvania tube has approximately the following characteristics:
- Heater - 2.5 volts AC
- .615 amperes
- 1.53 watts
