QBL4800

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: 5 V / 13.5 A

Description

High-frequency transmitting tetrode for amplifier, modulator, and frequency-multiplier service.

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: 13.5 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

Tetrode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0052 S
Amplification factor: 6.2
Max plate voltage: 4000 V
Max screen voltage: 500 V
Max plate dissipation: 500 W
Max screen dissipation: 30 W
Max cathode current: 350 mA

Promoted where the locked schema directly matches published RF values; frequency/service-specific limits and operating conditions are retained as parameter rows.

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 Philips Electron Tubes Handbook V4

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Maximum plate voltage
4000 V
RFPowerTube
Maximum screen voltage
500 V
RFPowerTube
Application
High-frequency transmitting tetrode for amplifier, modulator, and frequency-multiplier service.
SourceDescription
Service category
RF/AF power service as specified in source
RFPowerTube
Heater/filament voltage
5 V
RFPowerTube
Heater/filament current
13.5 A
RFPowerTube
Operating frequency
110 MHz
RFPowerAmplifier
Plate voltage
4000 V
RFPowerAmplifier
Plate current
315 mA
RFPowerAmplifier
Power output
930 W
RFPowerAmplifier
Maximum frequency
120 MHz
RFPowerAmplifier

Construction

Heating method
Direct
RFPowerTube
Device class
Tetrode
RFPowerTube

Characteristic

Transconductance
5200 µS
RFPowerTube
Screen-to-control-grid amplification factor
6.2
RFPowerTube

Capacitance

Plate capacitance
4.5 pF
RFPowerTube
Control-grid capacitance
12.7 pF
RFPowerTube

Data set 02

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristics

Heater/filament voltage
5 V
Heater/filament current
13.5 A
Transconductance
5200 uS
Screen-grid amplification factor
6.2

Other

Maximum plate/anode voltage
4000 V
Maximum screen-grid voltage
500 V
Maximum plate/anode dissipation
500 W
Maximum screen-grid dissipation
30 W
Operating plate voltage
4000 V
ClassC;Telegraphy;110MHz
RF output power
930 W
ClassC;Telegraphy;110MHz
Operating plate voltage
2400 V
TelevisionService;220MHz;Sync
RF output power
600 W
TelevisionService;220MHz;Sync
Maximum anode input power
1400 W
120MHz
Maximum grid-1 current
30 mA

Capacitance

Plate/anode capacitance
5.6 pF
Control-grid capacitance
12.8 pF
Plate-grid capacitance
0.05 pF