QB3500

Transmitting power tetrode designed for RF amplification, linear/SSB service, oscillation, modulation, broadcasting, or frequency multiplication.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 11 V / 10 A

Description

Directly heated transmitting tetrode for short-wave RF amplifier service. The supplied Philips source was read for heater or filament data, capacitances, limiting ratings, and representative RF/television operating conditions, with variant-sheet cross-references preserved.

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: 11 V
Nominal heater current: 10 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

Tetrode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0022 S
Amplification factor: 7.5
Max plate voltage: 3000 V
Max screen voltage: 800 V
Max plate dissipation: 350 W
Max screen dissipation: 100 W
Max cathode current: 350 mA

Published transmitting-tube ratings and principal characteristics promoted; additional RF operating points 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

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristics

Heater/filament voltage
11 V
Heater/filament current
10 A
Transconductance
2200 uS
Screen-grid amplification factor
7.5
Typical plate-voltage range
2000-3000 V
Typical screen-voltage range
500-800 V

Other

Maximum plate/anode voltage
3000 V
Maximum screen-grid voltage
800 V
Maximum plate/anode dissipation
350 W
Maximum screen-grid dissipation
100 W
Operating plate voltage
3000 V
ClassC;Telegraphy;Wavelength>150m
RF output power
690 W
ClassC;Telegraphy;Wavelength>150m
Maximum screen-grid dissipation
100 W

Capacitance

Plate-grid capacitance
0.02 pF