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Tuning Indicator ·Triode-TuningIndicator

EM11

Dual-sensitivity electron-ray tuning indicator with two shadow-angle systems for visual tuning over a broad range of receiver signal strengths.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
P8A
Base pins
-
Nominal heater
6.3 V / 100 mA

Description

Dual-sensitivity tuning indicator tube with two shadow-angle systems for receiver tuning indication.

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
-
Socket code
P8A
Base pins
-
Nominal heater voltage
6.3 V
Nominal heater current
100 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

2 physical sections, each with unique specifications.

Section 1

Tuning Indicator

X-ray radiationInterelectrode capacitances
Transconductance
0.000235 S
Max plate voltage
18.5 V
Max screen voltage
6.25 V
Max plate dissipation
0.5 W
Max cathode current
5 mA

Promoted ratings and characteristics are taken from the printed target-tube entry in the approved PDF.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Max plate voltage
300 V
Max plate dissipation
1 W
Max cathode current
5 mA

Second tuning-indicator/control system.

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

Tuning Indicator

Other

  • Indicator screen voltage

    250 V

  • Indicator screen voltage maximum

    250 V

  • Cold indicator screen voltage maximum

    550 V

Characteristic

  • Grid-control range

    0 to -4 V

    Range1

SECTION 2

Triode

Characteristic

  • Grid-control range

    0 to -20 V

    Range2

Data set 02

1959 Telefunken

Published operating points and test conditions from this source.

SECTION 2

Triode

Other

  • Target voltage

    250 V

  • Target current

    0.46 mA

  • Target voltage

    200 V

  • Target current

    0.33 mA

  • Target voltage

    100 V

  • Target current

    0.1 mA

  • Target voltage maximum

    250 V

  • Target voltage minimum

    90 V

  • Target cold voltage

    550 V

Data set 03

1981 Russian Tubes Katsnelson and Larionov

Published operating points and test conditions from this source.

SECTION 1

Tuning Indicator

Characteristic

  • Heater voltage

    6.3 V

    Published nominal/basic-parameter heater condition.

  • Heater current

    100 mA

    Published heater current.

  • Plate current

    0.475 mA

    Published basic-parameter operating point.

  • Screen current

    0.2 mA

    Published basic-parameter operating point.

  • Transconductance

    235 µS

    Published basic-parameter value; normalized to µS.

  • Logarithmic input-current range lower bound

    0.000000001 mA

    Published in the filename-designated tube entry.

  • Logarithmic input-current range upper bound

    0.1 mA

    Published in the filename-designated tube entry.

  • Service life

    2000 h

    Published in the filename-designated tube entry.

Other

  • Maximum plate voltage

    18.5 V

    Published limiting operating value.

  • Maximum screen voltage

    6.25 V

    Published limiting operating value.