Voltage - Dual Triode (similar high frequency) ·Triode-Triode
Medium-mu twin triode with separate cathodes and series/parallel heater, intended for carrier-telephone and general amplifier, mixer, oscillator, and multivibrator service through VHF frequencies.
The 407A is a nine-pin medium-mu twin triode with separate cathodes and a series/parallel heater, designed for carrier telephony and amplifier, mixer, oscillator, or multivibrator applications through VHF.
Small-button Noval 9-contact
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.
2 physical sections, each with unique specifications.
Section 1
Promoted fields mapped from printed maximum-rating and characteristic headings; additional published values preserved in parameter rows. Representative row for repeated identical physical sections.
Section 2
Second identical physical triode section; added to align rows with SectionCount.
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.
Transconductance
5500 µS
Amplification Factor
35
Maximum Plate Voltage
330 V
Maximum Plate Dissipation
1.65 W
Maximum Cathode Current
18 mA
Plate Voltage
150 V
ClassA,EachSection
Data set 02
Published operating points and test conditions from this source.
Plate Resistance
6400 ohm
Typical
Transconductance
5500 uS
Typical
Amplification Factor
35
Typical
Maximum Signal Power Output
1 W
Data set 03
Published operating points and test conditions from this source.
Plate supply voltage
130 V
ClassA;EachSection
Cathode bias resistor
200 Ohm
ClassA;EachSection
Plate current
7.6 mA
ClassA;EachSection
Plate supply voltage
150 V
ClassA;EachSection
Cathode bias resistor
240 Ohm
ClassA;EachSection
Plate current
8.2 mA
ClassA;EachSection
Plate supply voltage
300 V
ClassAB;PushPull;TwoTubes
Load impedance plate-to-plate
40000 Ohm
ClassAB;PushPull;TwoTubes
Maximum signal power output
1 W
ClassAB;PushPull;TwoTubes
Transconductance minimum
4500 uS
EachSection
Transconductance maximum
6500 uS
EachSection
Transconductance
5400 uS
ClassA;EachSection
Amplification factor
35 ratio
ClassA;EachSection
Plate resistance
6500 Ohm
ClassA;EachSection
Transconductance
5500 uS
ClassA;EachSection
Plate resistance
6400 Ohm
ClassA;EachSection
Data set 04
Published operating points and test conditions from this source.
Typical plate voltage
300 V
ClassAB
Typical cathode resistor
800 ohm
ClassAB
Load impedance plate-to-plate
27000 ohm
PushPull
Signal power output
1 W
PushPull
Maximum plate voltage
330 V
PromotedValue
Maximum plate dissipation
1.8 W
PromotedValue
Maximum cathode current
14 mA
PromotedValue
Plate current at 150 V
6.2 mA
EachSection
Plate resistance
6400 ohm
PromotedValue
Transconductance
0.0055 A/V
PromotedValue
Amplification factor
35
PromotedValue
Grid-to-plate capacitance
1.3 pF
EachSection
Input capacitance
2.25 pF
EachSection
Output capacitance
1 pF
EachSection
Data set 05
Published operating points and test conditions from this source.
Heater voltage
20 V
Heater current
100 mA
Plate resistance
6400 ohm
Transconductance
3699.9999999999995 uS
Amplification factor
35
Maximum plate voltage
330 V
Maximum plate dissipation
1.6 W
Data set 06
Published operating points and test conditions from this source.
Maximum plate voltage
- to 330 V
Maximum plate dissipation
- to 1.35 W
Maximum cathode current
- to 18 mA
Plate resistance
6350 Ω
Transconductance
5500 µS
Amplification factor
35
Plate supply voltage
150 V
ClassA
Cathode resistor
240 Ω
ClassA
Amplification factor
35
ClassA
Plate resistance
6350 Ω
ClassA
Transconductance
5500 µS
ClassA
Plate current
8.2 mA
ClassA
Grid voltage for maximum plate current
-10 V
ClassA
Grid to plate (Each unit)
1.1 pF
Data set 07
Published operating points and test conditions from this source.
Heater Voltage
20 volts
Heater Voltage . . . . . . . . . . . . . . . . 20 or 40 volts
Plate Current per Section. . . }. E, =
130 volts
Plate Current per Section. . . }. E, = 130 volts {j 8.2 milliamperes
Transconductance per Section. E, =
-2 volts
Transconductance per Section. E, = -2.0 volts 5500 micromhos
Heater Current
100 milliamperes
Heater Current 100 50 milliamperes
Plate Voltage
330 volts
Plate Voltage. 330 volts
Plate Current
20 milliamperes
Plate Current. . 20 milliamperes
Heater Cathode Voltage
130 volts
Heater Cathode Voltage . 130 volts
Fixed Bias
1 megohm
Fixed Bias 1 megohm
Plate vVoltage
150 volts
Plate vVoltage. 150 150 volts
Grid Voltage
-2 volts
Grid Voltage -2.0 - volts
Plate Current
8.2 milliamperes
Plate Current . 8.2 8.2 milliamperes
Transconductance
5500 micromhos
Transconductance. 5500 5500 micromhos
Plate Current of
10 microamperes
Plate Current of 10 microamperes -8 - volts
Plate voltage .,
200 volts
Plate voltage ., . . . . . . . 200 300 volts
Peak A-F Grid-to-Grid voltage. . . . P N
20 volts
. Peak A-F Grid-to-Grid voltage. . . . P N 20 volts
Zero Signal Plate Current per Section
5 milliamperes
Zero Signal Plate Current per Section . . . . . . . . 5.0 4.7 milliamperes
Signal Power Output. . . e e e e e v
0.4 watt
Signal Power Output. . . e e e e e v . . . 0.40 0.95 watt
Total Harmonic Distortion Less Tha.n e e e e e e e
5 per cent
Total Harmonic Distortion Less Tha.n e e e e e e e 5 10 per cent
Plate Dissipation
1.6 watts
Plate Dissipation 1.6 watts
Maximum Signal Plate Current per Section
5.6 milliamperes
Maximum Signal Plate Current per Section . . . . . . 5.6 6.0 milliamperes