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Voltage - Triode (with diode, heptode or hexode) ·Diode-Diode-Triode

25S

Directly heated double-diode triode for detector, AVC, and audio voltage-amplifier service in battery receivers. Paired diodes provide signal and control rectification while the triode supplies subsequent audio gain.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 3
Base: -
Socket code: UX6
Base pins: 6
Nominal heater: 2 V / 60 mA

Description

Double-diode triode intended for diode detection/AVC and triode amplification.

Socket description

Small 6-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: UX6
Base pins: 6
Nominal heater voltage: 2 V
Nominal heater current: 60 mA
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

3 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Detector/AVC diode section 1; source publishes no separate fixed electrical ratings for the diode.

Section 2

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Detector/AVC diode section 2; source publishes no separate fixed electrical ratings for the diode.

Section 3

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 35000 Ω
Transconductance: 0.000575 S
Amplification factor: 20
Max plate voltage: 135 V

Triode section Class A1 characteristics.

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 01

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 2

Diode

Other

Number of identical diode units
2 count
IdenticalSectionsCompressed

SECTION 3

Triode

Other

Plate voltage
135 V
ClassA
Grid bias
-3 V
ClassA
Plate current
0.8 mA
ClassA

Capacitance

Grid-to-plate capacitance
3.8 pF
TriodeSection
Input capacitance
2 pF
TriodeSection
Output capacitance
3 pF
TriodeSection

Data set 02

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 3

Triode

Characteristic

Tension filament (CC) ... ... .. .. . .. .. 2,0 Volts
2 V
Tension filament (CC) ... ... .. .. . .. .. 2,0 Volts
Courant filament ... .. v cor o e e e 0,06 ampére
60 mA
Courant filament ... .. v cor o e e e 0,06 ampére
Tension filament ... ... . . e 2,0 Volts
2 V
Tension filament ... ... . . e 2,0 Volts
Courant plaque ... ... ... ... .. .. o .. 0,8 ma
0.8 ma
Courant plaque ... ... ... ... .. .. o .. 0,8 ma
Résistance interne ... ... ... ... ... .. .. ... 35,000 ohms
35 ohms
Résistance interne ... ... ... ... ... .. .. ... 35,000 ohms
son retour s’effectuant au péle négatif de 1a tension de polarisation.
1 A
son retour s’effectuant au péle négatif de 1a tension de polarisation.

Other

Tension plaque ... .. ... . 0 L L 135 Volts max.
135 V
Tension plaque ... .. ... . 0 L L 135 Volts max.

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 3

Triode

Other

Filament Voltage
2 V
Nominal
Filament Current
60 mA
Nominal
Control Grid Voltage
-3 V
ClassA1
Plate Current
0.8 mA
ClassA1

Capacitance

Grid To Plate Capacitance
3.6 pF
Input Capacitance
1.6 pF
Output Capacitance
1.9 pF

Characteristic

Plate Resistance
35000 ohm
ClassA1
Transconductance
575 uS
ClassA1
Amplification Factor
20
ClassA1