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25C6GA

High-sensitivity beam-power amplifier designed to obtain substantial output from comparatively low DC supply voltages, electrically related to the 50C6GA apart from heater ratings.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: IO
Base pins: 7
Nominal heater: 25 V / 300 mA

Description

The 25C6GA is a beam power amplifier intended for high power output and high sensitivity from comparatively low DC supplies; aside from heater ratings it is equivalent to the 50C6GA.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: IO
Base pins: 7
Nominal heater voltage: 25 V
Nominal heater current: 300 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

1 physical section, each with unique specifications.

Section 1

Beam Power

X-ray radiationInterelectrode capacitances

Plate resistance: 18300 Ω
Transconductance: 0.0071 S
Max plate voltage: 200 V
Max screen voltage: 200 V
Max plate dissipation: 12.5 W
Max screen dissipation: 1.75 W

Class A1 values include 135 V and 200 V plate operating points.

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

Heater voltage
25 V
Nominal
Heater current
300 mA
Nominal
Plate voltage
135 V
ClassA; OperatingPoint1
Plate voltage
200 V
ClassA; OperatingPoint2
Screen voltage
135 V
ClassA; OperatingPoint1
Screen voltage
135 V
ClassA; OperatingPoint2
Control-grid voltage
-13.5 V
ClassA; OperatingPoint1
Control-grid voltage
-14 V
ClassA; OperatingPoint2
Load resistance
2000 ohm
ClassA; OperatingPoint1
Load resistance
2600 ohm
ClassA; OperatingPoint2
Power output
3.6 W
ClassA; OperatingPoint1
Power output
6 W
ClassA; OperatingPoint2
Total harmonic distortion
10 %
ClassA; OperatingPoint1
Total harmonic distortion
10 %
ClassA; OperatingPoint2
Maximum grid 2 supply voltage
200 V
DesignCenter

Characteristic

Zero-signal plate current
58 mA
ClassA; OperatingPoint1
Zero-signal plate current
61 mA
ClassA; OperatingPoint2
Zero-signal screen current
3.5 mA
ClassA; OperatingPoint1
Zero-signal screen current
2.2 mA
ClassA; OperatingPoint2
Plate resistance
9300 ohm
ClassA; OperatingPoint1
Plate resistance
18300 ohm
ClassA; OperatingPoint2
Transconductance
7000 uS
ClassA; OperatingPoint1
Transconductance
7100 uS
ClassA; OperatingPoint2

Data set 02

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

Maximum plate voltage
200 V
WholeTube
Maximum screen supply voltage
200 V
WholeTube
Maximum plate dissipation
10.5 W
WholeTube
Maximum screen dissipation
1.75 W
WholeTube
Plate voltage
135 V
ClassA1
Screen voltage
135 V
ClassA1
Plate current
59 mA
ClassA1
Transconductance
5000 µS
ClassA1
Plate resistance
9300 ohm
ClassA1
Maximum signal power output
3.6 W
ClassA1