U77

Indirectly heated two-plate full-wave rectifier, co-designated GZ34, for center-tapped AC supplies. Its equipotential cathode provides substantial current with relatively efficient vacuum rectification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: -
Nominal heater: 5 V / 1.9 A

Description

Two-plate full-wave rectifier with equipotential cathode and octal base for center-tapped AC rectification; co-designated GZ34.

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: 5 V
Nominal heater current: 1.9 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

2 physical sections, each with unique specifications.

Section 1

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 1500 V
Rectifier nominal output current: 250 mA

Representative section for two electrically identical sections.

Section 2

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 1500 V
Rectifier nominal output current: 250 mA

Second physical rectifier section; electrical properties populated from applicable published ratings.

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

2026 Genalex Rebrand

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Characteristic

DiodePlateCurrent
180 to 280 mA
Plate 17 V

Other

RectifiedCurrent
180 mA
Transformer secondary 2 x 550 V; load 3000 ohm; cathode-chain capacitance 40 µF
Peak Plate Current
825 mA
TurnOnSurgeCurrent
3.7 A

SECTION 2

Rectifier

Characteristic

DiodePlateCurrent
180 to 280 mA
Plate 17 V
DiodePlateCurrent
180 to 280 mA
Plate 17 V

Other

RectifiedCurrent
180 mA
Transformer secondary 2 x 550 V; load 3000 ohm; cathode-chain capacitance 40 µF
RectifiedCurrent
180 mA
Transformer secondary 2 x 550 V; load 3000 ohm; cathode-chain capacitance 40 µF
Peak Plate Current
825 mA
Peak Plate Current
825 mA
TurnOnSurgeCurrent
3.7 A