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Power - Pentode Single (NOT beam) (under 10W) ·Pentode

293A

Power/output pentode designed for Class-A, single-ended, or push-pull audio-frequency output amplification.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
MEDIUM6
Base pins
6
Nominal heater
10 V / 320 mA

Description

Suppressor-grid power pentode designed for Class A audio-frequency power amplification.

Socket description

Medium 6-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
MEDIUM6
Base pins
6
Nominal heater voltage
10 V
Nominal heater current
320 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

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
100000 Ω
Transconductance
0.001175 S
Max plate voltage
250 V
Max screen voltage
200 V
Max plate dissipation
5 W
Max screen dissipation
1 W
Max cathode current
30 mA
Rectifier max heater-cathode voltage
150 V

Typical characteristics use 180 V Class-A column.

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

2026 Western Electric 200s

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Grid to Plate Capacitance

    0.66 pF

  • Input Capacitance

    6.2 pF

  • Output Capacitance

    6.5 pF

Other

  • Plate Voltage

    180 V

    ClassA

  • Screen Grid Voltage

    180 V

    ClassA

  • Control Grid Voltage

    -18 V

    ClassA

  • Zero Signal Plate Current

    15.8 mA

    ClassA

  • Maximum Signal Plate Current

    17 mA

    ClassA

  • Load Resistance

    11500 ohm

    ClassA

  • Maximum Signal Power Output

    1.3 W

    ClassA