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HR8

Indirectly heated high-voltage half-wave vacuum rectifier for EHT and related supplies. Its four-volt heater provides multi-kilovolt operation with greater current than smaller HR types.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: IO
Base pins: -
Nominal heater: 4 V / 1.25 A

Description

Indirectly heated half-wave high-voltage vacuum rectifier.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: IO
Base pins: -
Nominal heater voltage: 4 V
Nominal heater current: 1.25 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

Rectifier

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 12500 V
Rectifier nominal output current: 50 mA
Rectifier peak forward current: 350 mA
Rectifier warm-up time: 60 s

Published Ferranti ratings and characteristics promoted where applicable; additional electrical, pulse, regulator, microwave, and operating data retained as parameters.

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

1963 Ferranti

Published operating points and test conditions from this source.

SECTION 1

Rectifier

Application

Application
High-voltage half-wave rectifier
CapacitorInputFilter

Other

PIV no-load
14 kV
CapacitorInputFilter
PIV working
12.5 kV
CapacitorInputFilter
RMS input voltage maximum
5 kV
CapacitorInputFilter
Peak anode current maximum
350 mA
CapacitorInputFilter
Rectified current maximum
50 mA
CapacitorInputFilter
Reservoir capacitance maximum
1 uF
CapacitorInputFilter
Supply impedance minimum
4000 ohm
CapacitorInputFilter
Switching delay minimum
60 s
CapacitorInputFilter
Conditional PIV working
15 kV
CapacitorInputFilter
Conditional rectified current maximum
40 mA
CapacitorInputFilter
Conditional peak anode current maximum
300 mA
CapacitorInputFilter