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U309

Marconi indirectly heated booster diode for television flyback and horizontal-deflection service, rated around 4 kV inverse voltage and 170 mA rectified current.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: B9A
Base pins: -
Nominal heater: 20 V / 300 mA

Description

The Marconi U309 is a indirectly heated booster diode for television flyback 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: -
Nominal heater voltage: 20 V
Nominal heater current: 300 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

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 4000 V
Rectifier nominal output current: 170 mA
Rectifier peak forward current: 1 A
Rectifier max heater-cathode voltage: 350 V

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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Other

Heater/filament voltage
20 V
Heater/filament current
300 mA
Peak inverse voltage
4000 V
Nominal/maximum output current
170 mA
Peak anode current
1 A
Maximum heater-cathode voltage
350 V

Construction

Rectifier topology
Half-wave

Capacitance

Anode capacitance
8 pF