Power - Triode ·Triode
Transmitting power triode for radio-frequency amplifier and oscillator duty. Its published operating conditions emphasize substantial RF output, plate input, and dissipation rather than low-level receiving applications.
United Electronics type 242B: A-F power amplifier and Class A/AB modulator. The datasheet provides general ratings, maximum ratings, installation guidance, and representative operating conditions for continuous service.
Super Jumbo 4-pin bayonet
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Promoted fields mapped from published ratings/characteristics; additional published values preserved in parameter table.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Filament voltage
10 V
Filament current
3.25 A
Maximum direct plate voltage
1250 V
Maximum plate dissipation
100 W
Data set 02
Published operating points and test conditions from this source.
Filament Voltage
10 Volt
Filament Voltage 10 Volts
Nominal Filament Current
3.25 Amperes
Nominal Filament Current 3.25 Amperes
Average Characteristics with Plate Voltage, Eb, of
1000 Volt
Average Characteristics with Plate Voltage, Eb, of 1000, Grid Voltage, Ec, of -50 and
Filament Voltage Ea, of
10 Volt
Filament Voltage Ea, of 10 volts D.C.
Plate Resistance
3500 Ohms
Plate Resistance 3,500 Ohms
A m p l i fi c a t i o n Factor
12.5
A m p l i fi c a t i o n Factor 12.5
Mutual Conductance
3570 Micromhos
Mutual Conductance 3,570 Micromhos
Grid Bias Voltage
-50 Volt
Grid Bias Voltage -50 Volts
Load Impedance
7000 Ohms
Load Impedance 7,000 Ohms
Undistorted Output
10 Watts
Undistorted Output 10 Watts
Grid Bias Voltage
-100 Volt
Grid Bias Voltage -100 - 1 0V
Average thermionic emission
1.5 amperes
Average thermionic emission 1.5 amperes
Amplification factor
12.5
Amplification factor 12.5
Plate resistance
3500 ohms
Plate resistance 3500 ohms
Grid to plate transconductance
3600 micromhos
Grid to plate transconductance 3600 micromhos
Direct plate voltage
1250 volt
Direct plate voltage 1250 1000 volts
Grid bias
-6 volts
Grid bias - 6 8 — 42 volts
Direct plate current
68 milliamperes
Direct plate current 68 85 milliamperes
Plate dissipation
8 watts
Plate dissipation 8 5 85 watts
Load impedance
8000 ohms
Load impedance 8000 7000 ohms
Undistorted output
22 watts
Undistorted output 22.0 12.0 watts
Grid bias
-8 volts
Grid bias - 8 0 — 55 volts
Plate dissipation
100 watts
Plate dissipation 100 100 watts
Load resistance, plate-to-plate
7600 ohms
Load resistance, plate-to-plate 7600 6000 ohms
Load resistance, per tube
1900 ohms
Load resistance, per tube 1900 1500 ohms
Direct plate voltage
1000 volt
Direct plate voltage 1000 volts
Direct plate current for carrier conditions
150 milliamperes
Direct plate current for carrier conditions 150 milliamperes
Grid bias
-60 volts
Grid bias — 60 volts
Direct plate voltage
1250 volt
Direct plate voltage 1250 1000 1 0 0 0 v vco l t s
Direct plate current
150 milliamperes
Direct plate current 150 150 150mmilliamperes
Direct plate voltage
1000 volt
Direct plate voltage 1000 750 volts
Direct plate current
150 milliamperes
Direct plate current 150 150 milliamperes
Grid bias
-160 volts
Grid bias —160 -120 volts
or circuit breaker should remove the plate voltage if the plate current exceeds
175 volt
or circuit breaker should remove the plate voltage if the plate current exceeds 175 milliamperes.
circuit, reduced plate voltage or a series resistance of
1000 volt
circuit, reduced plate voltage or a series resistance of 1000 to 5000 ohms in the plate circuit should
A
5 volt
A 5% decrease in filament voltage reduces the thermionic emission approximately 25%. Either
A resistance of
20 ohms
A resistance of 20 to 30 ohms of three watt rating is suitable.
voltages off,
30 volt
voltages off, 30% above normal voltage for 10 minutes followed by a longer period at normal voltage.
on the basis of
5
on the basis of 5% second harmonic distortion.
of the plate voltage. For complete or
100 volt
of the plate voltage. For complete or 100% modulation, the plate voltage varies from zero
fourth of the peak power output under
100 volt
fourth of the peak power output under 100% modulation. In this case, since the plate voltage
Maximum Plate Voltage
1250 Volt
Maximum Plate Voltage 1,250 Volts
Maximum Plate Current
0.15 Ampere
Maximum Plate Current 0.150 Ampere
Maximum Plate Voltage
1000 Volt
Maximum Plate Voltage 1,000 Volts
Maximum Plate Current
0.85 Ampere
Maximum Plate Current 0.85 Ampere
Maximum Plate Dissipation
85 Watts
Maximum Plate Dissipation 85 Watts
Maximum Plate Voltage
12 Volt
Maximum Plate Voltage 1,2 5
Maximum Non-modulated Plate Voltage (D.C.)
1250 Volt
Maximum Non-modulated Plate Voltage (D.C.) 1,250 Volts
Max. direct plate voltage
1250 volt
Max. direct plate voltage 1250 volts
Max. direct plate current
150 milliamperes
Max. direct plate current 150 milliamperes
Max. plate dissipation
100 watts
Max. plate dissipation 100 watts
Max. direct grid current
50 milliamperes
Max. direct grid current 50 milliamperes
Max. r-f grid current
5 amperes
Max. r-f grid current 5 amperes
Max. frequency for the above ratings
6 megacycles
Max. frequency for the above ratings 6 megacycles
Max. plate voltage for upper frequency limit of
30 volt
Max. plate voltage for upper frequency limit of 30 Mc. . 600 volts
Max. plate voltage for frequencies between
6 volt
Max. plate voltage for frequencies between 6 and 30 Mc in proportion.
Approximate maximum output
2 watts
Approximate maximum output—2 tubes 200 165 watts
Max. direct grid current
50 milliamperes
Max. direct grid current 50 50 milliamperes