Data set 01
1950 General Electric Transmitting Types
Published operating points and test conditions from this source.
SECTION 1
Rectifier
Characteristics
Filling
Mercury vapor
Peak voltage drop typical
15 V
Rectifier - Half Wave ·Rectifier
266B
Directly heated half-wave mercury-vapor rectifier for high-voltage power supplies. Rated for approximately 22 kV peak inverse voltage and 40 A peak current with the low arc drop characteristic of mercury vapor.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- MEDIUM5
- Base pins
- -
- Nominal heater
- 5 V / 30 A
Description
Half-wave mercury-vapor rectifier for high-voltage power-supply service.
Socket description
Medium 5-contact transmitting-tube base
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- MEDIUM5
- Base pins
- -
- Nominal heater voltage
- 5 V
- Nominal heater current
- 30 A
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
1 physical section, each with unique specifications.
Section 1
Rectifier
X-ray radiationInterelectrode capacitances
- Rectifier peak inverse voltage
- 22000 V
- Rectifier nominal output current
- 5 A
- Rectifier peak forward current
- 40 A
- Rectifier forward voltage drop
- 15 V
- Rectifier warm-up time
- 300 s
22 kV PIV applies with condensed mercury 20–40 C; 12.5 kV for 20–50 C. Peak/average cathode-current ratings depend on in-phase vs quadrature operation.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 02
2026 Western Electric 200s
Published operating points and test conditions from this source.
SECTION 1
Rectifier
Other
Filament Current
42 A to 46 A
At5.0V
Maximum Peak Inverse Anode Voltage
22000 V
CondensedMercuryTemperature=20to40C
Maximum Peak Inverse Anode Voltage
12500 V
CondensedMercuryTemperature=20to50C
Peak Cathode Current
20 A
InPhaseOperation
Peak Cathode Current
40 A
QuadratureOperation
Average Cathode Current
5 A
InPhaseOperation
Average Cathode Current
10 A
QuadratureOperation
Surge Cathode Current
200 A
MaxDuration=0.2s
Frequency
150 Hz
Characteristic
Anode Voltage Drop
15 V
CriticalAnodeVoltage
100 V