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

IL861

Co-designation of the EL861 steep-slope output pentode, designed for long service life in output amplifiers used in long-distance communications equipment. It combines broadband power capability with extended professional life.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
20 V / 120 mA

Description

IL861 is a printed co-designation/equivalent on the EL861 source sheet. A steep-slope output pentode designed for long service life in output amplifiers used in long-distance communications equipment.

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
20 V
Nominal heater current
120 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
4.5 W
Max screen dissipation
1.2 W
Max cathode current
30 mA

Long-life output pentode ratings from shared source sheet.

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