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Power - Triode ·Triode

4C27

National Union 4C27 indirectly heated coaxial VHF pulsed power oscillator triode for 200–600 MHz, rated for 50 kW peak RF output and requiring forced-air cooling.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
6 V / 6.5 A

Description

VHF coaxial triode for pulsed oscillator service in roughly the 200–600 MHz range.

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
6 V
Nominal heater current
6.5 A
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

Triode

X-ray radiationInterelectrode capacitances
Amplification factor
23
Max plate voltage
8000 V
Max plate dissipation
150 W

National Union 4C27 coaxial VHF pulsed power triode, RMA 1946. Heater 6.0 V ±5%, 6.5 A, indirectly heated oxide cathode. Maximum instantaneous PULSED anode 8000 V (not continuous DC), anode dissipation 150 W, negative grid voltage magnitude 1000 V. Mu 23; gm and rp not specified. Typical 215 MHz Class C pulsed oscillator: anode instantaneous 8 kV, repetition 400 Hz, pulse width 2 µs, peak RF power 50 kW; 200–600 MHz intended. Capacitances Cgp 8 pF, Cgk 11 pF, Cpk 2.25 pF. Forced air 6 CFM anode radiator, 1 CFM grid seal/lead.

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 National Union

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • as a pulsed V.H.F. oscillator in the

    200 mc

    Published source value; see source line context.

  • rated, one tube will deliver

    50 kw

    Published source value; see source line context.

  • Heater Voltage

    8 Volts

    Published source value; see source line context.

  • Grid Voltage

    -1000 Volts

    Published source value; see source line context.

  • Anode Voltage (Instantaneous)

    8000 Volts

    Published source value; see source line context.

  • Anode Dissipation

    150 Watts

    Published source value; see source line context.

  • Length (less heater leads)

    3 inches

    Published source value; see source line context.

  • Length (including heater leads)

    5 inches

    Published source value; see source line context.

  • Width

    2 inches

    Published source value; see source line context.

  • Power Output

    50 kw

    Published source value; see source line context.

Characteristic

  • Grid to Plate

    8 uuf

    Published source value; see source line context.

  • Plate to Cathode

    2.25 uuf

    Published source value; see source line context.