EL861

High-transconductance power pentode designed for wideband and professional amplifier service. Its steep slope and output capability support demanding broadband load-driving stages.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 230 mA

Description

High-transconductance power pentode for wideband and professional amplifier service.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 230 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: 300000 Ω
Transconductance: 0.011 S
Max plate voltage: 210 V
Max screen voltage: 210 V
Max plate dissipation: 6 W
Max screen dissipation: 1.2 W
Max cathode current: 50 mA

Published ratings and characteristics promoted from the approved source.

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 RFT Rundfunk Technik

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate voltage
210 V
Screen-grid voltage
210 V
Cathode resistance
120 Ω
Plate current
20 mA
Screen-grid current
5.3 mA
Cold plate voltage maximum
550 V
Cold screen-grid voltage maximum
550 V

Characteristic

Transconductance
11 mA/V
Equivalent noise resistance
1.2 kΩ
Voltage gain, preamplifier
175
Preamplifier