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Voltage Radio Detector Converter ·Octode

AK1

Octode frequency changer for early superheterodyne receivers, combining local-oscillator and mixer functions in one multi-grid valve. Its control characteristic also supports gain regulation in the converter stage.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
C35
Socket code
P8A
Base pins
8
Nominal heater
4 V / 650 mA

Description

Telefunken octode frequency changer for superheterodyne receivers, providing a controllable multi-grid mixer function.

Socket description

European 8-pin side-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
C35
Socket code
P8A
Base pins
8
Nominal heater voltage
4 V
Nominal heater current
650 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

C35 - 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

Octode

X-ray radiationInterelectrode capacitances
Plate resistance
1900000 Ω
Transconductance
0.0006 S
Max plate voltage
200 V
Max screen voltage
90 V
Max cathode current
10 mA

Octode section.

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

1938 Philips Miniwatt Vacuum Tube Catalog

Published operating points and test conditions from this source.

SECTION 1

Octode

Other

  • Plate voltage

    200 V

  • Screen voltage

    90 V

  • Screen current

    2 mA

Characteristics

  • Conversion transconductance

    600 µS

  • Grid-anode capacitance

    0.066 pF

Data set 02

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Octode

Characteristics

  • Heater voltage

    4 V

  • Heater current

    650 mA

  • Plate voltage

    200 V

  • Screen/auxiliary voltage

    90 V

  • Plate current

    1.6 mA

  • Screen/auxiliary current

    2 mA

  • Transconductance

    600 uS

    Conversion

  • Plate resistance

    1900000 ohm