GU81

Medium-power transmitting pentode intended for RF power amplifiers, oscillators, and modulation stages. Its construction is optimized for professional radio-frequency generation and output service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: GIANT7
Base pins: 7
Nominal heater: 12.6 V / 10.5 A

Description

Medium-power transmitting pentode intended for RF power amplifiers, oscillators, and modulation stages.

Socket description

Giant 7-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: GIANT7
Base pins: 7
Nominal heater voltage: 12.6 V
Nominal heater current: 10.5 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

Pentode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0055 S
Max plate voltage: 3000 V
Max screen voltage: 600 V
Max plate dissipation: 450 W
Max screen dissipation: 120 W

Representative electrical section; repeated identical sections are compressed where applicable.

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

196X Lamina

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Maximum frequency
50 MHz
Input capacitance
28.5 pF
Output capacitance
23.5 pF
Grid-plate capacitance
<0.1 pF