R125C

Long-life voltage-amplifier triode incorporating two diode sections, intended for dependable detector and amplification service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 3
Base: -
Socket code: -
Base pins: -
Nominal heater: 18 V / 400 mA

Description

Long-life voltage-amplifier triode with two diode sections.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 18 V
Nominal heater current: 400 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

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 13000 Ω
Transconductance: 0.0025 S
Amplification factor: 32.5
Max plate voltage: 275 V
Max plate dissipation: 1.5 W
Max cathode current: 10 mA

Triode section; promoted values are taken from the approved source where explicitly published.

Section 2

Diode

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 150 V
Rectifier nominal output current: 1.5 mA

Diode section; promoted values are taken from the approved source where explicitly published.

Section 3

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Physical diode section added during approved section-structure reconciliation.

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

1953 La Radiotechnique

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Indirect (cathode isolee du filament)
18 V
Triode

Other

Plate voltage
250 V
Triode
Tension de la grille
5.5 V
Triode
Plate current
5 mA
Triode
Plate resistance
0 ohm
Triode
Plate voltage
275 V
Triode
Plate dissipation
1.5 W
Triode
Cathode current
10 mA
Triode

SECTION 2

Diode

Other

ldj
1 Mohm
Diode
Ida
1 Mohm
Diode
Courant de la diode 1
15 mA
Diode
Courant de la diode P,
1.5 mA
Diode
ldo
1 Mohm
Diode

Capacitance

Input capacitance
8 pF
Diode
Output capacitance
12 pF
Diode
Capacite anode-grille
2 pF
Diode
Capacite de la diode 1
4 pF
Diode
Capacite de la diode 2
4 pF
Diode
Capacite diode 1 - diode 2
1 pF
Diode
Input capacitance
105 pF
Diode

Characteristic

Indirect (cathode isolee du filament)
18 V
Diode