Data set 01
1937 Osram Valves
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Optimum load resistance
2400 ohm
Published operating data
Power - Triode ·Triode
PX4
Classic Marconi/Osram directly heated audio power triode designed as a high-output receiver valve. Moderate plate dissipation, low amplification factor, and useful transconductance suit transformer-coupled Class A loudspeaker output.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- UX4
- Socket code
- B4
- Base pins
- 4
- Nominal heater
- 4 V / 1 A
Description
Directly heated PX4 audio output triode. The supplied Emission Labs sheet was read for filament data, maximum ratings, representative operating points, gm/rp/mu, output conditions, capacitances, and rectifier filter conditions as applicable.
Socket description
European 4-pin base
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- UX4
- Socket code
- B4
- Base pins
- 4
- Nominal heater voltage
- 4 V
- Nominal heater current
- 1 A
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
UX4 - 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
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 830 Ω
- Transconductance
- 0.006 S
- Amplification factor
- 5
- Max plate voltage
- 250 V
- Max plate dissipation
- 12 W
- Max cathode current
- 80 mA
Published maximum ratings and characteristics audited; remaining useful numerical data retained in parameter table.
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
193X Osram
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Heater/Filament Voltage
4 V
Published datasheet value
Heater/Filament Current
1 A
Published datasheet value
Maximum Anode Voltage
250 V
Published datasheet value
Maximum Anode Dissipation
12 W
Published datasheet value
Characteristics
Plate Resistance
830 ohm
Published datasheet value
Mutual Conductance
6000 µS
Published datasheet value
Amplification Factor
5
Published datasheet value
Data set 03
1955 Marconi
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
PX
4 W
PX 4, Super-Power,
Marconi PX
4 W
Marconi PX.4 is a super-power output
valve for powerful receivers, capable | FuameNrvoLs aomax J1 L)
1 W
valve for powerful receivers, capable | FuameNrvoLs aomax J1 L) 1]
transformer output is desirable. In [1]
50
transformer output is desirable. In 50"%1 1 1
transformer output is desirable. In [2]
1
transformer output is desirable. In 50"%1 1 1
transformer output is desirable. In [3]
1
transformer output is desirable. In 50"%1 1 1
transformer output is desirable. In [4]
1
transformer output is desirable. In 50"%1 1 1
Anode (I‘j e.galtal_v © Anodge
10
Anode (I‘j e.galtal_v © Anodge 10
Anode Volts—Anode Current curve for PX
4 A
Anode Volts—Anode Current curve for PX 4.
Published value [1]
60 mA/V
60~§ i) MUTUAL CONDUCTANCE 6 0wmAN |
Published value [2]
6 mA/V
60~§ i) MUTUAL CONDUCTANCE 6 0wmAN |
Published value [3]
0 mA/V
60~§ i) MUTUAL CONDUCTANCE 6 0wmAN |
Data set 04
2026 Emission Labs
Published operating points and test conditions from this source.
SECTION 1
Triode
Characteristics
Filament voltage
4 V
Filament current
1.6 A
Plate resistance
875 ohm
ClassA
Amplification factor
4.6
ClassA
Transconductance
5300 uS
ClassA
Other
Plate voltage
300 V
ClassA
Plate current
50 mA
ClassA
Grid voltage
-36.5 V
ClassA
Load resistance
3500 ohm
ClassA
Output power
4.5 W
ClassA