QF41

Tunable 3-cm-band TR gas-discharge cell with keep-alive electrode for microwave duplexer receiver protection and rapid recovery.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: -

Description

Ferranti QF41 is a tuneable 3 cm-band transmitter-receiver (T.R.) gas-discharge cell for microwave duplexer protection. It uses a keep-alive electrode and is rated for 50 kW peak transmitter power, with published leakage, breakdown and recovery characteristics.

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: -
Nominal heater current: -
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

MicrowaveTRSwitch

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Microwave T.R. gas-discharge cell; device-specific primer, breakdown, leakage, recovery, frequency and power data are retained in 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 Ferranti

Published operating points and test conditions from this source.

SECTION 1

MicrowaveTRSwitch

Other

Maximum transmitter power
50 kW
Peak
VSWR
1.4
Low power
Maximum insertion loss at resonance
1.2 dB
Low power
Maximum insertion loss 15 Mc/s off resonance
1.5 dB
Low power
Maximum spike leakage energy
0.1 erg/pulse
40 kW peak
Maximum breakdown power
250 mW
High power
Maximum recovery time to 6 dB loss
4 us
40 kW peak
Maximum keep-alive breakdown voltage
1000 V
Keep-alive electrode
Keep-alive current
100 to 150 uA
Recommended operating range; value shown at upper bound

Characteristic

Preset tuning range
100 Mc/s
± about centre frequency
Loaded Q
130
Approximate, low level
Typical VSWR at resonance
1.1
Approximate, low level
Typical insertion loss at resonance
0.8 dB
Low level
Typical spike leakage energy
0.06 erg/pulse
40 kW peak
Typical flat leakage power
20 mW
40 kW peak
Typical breakdown power
100 mW
High power
Typical keep-alive breakdown voltage
700 V
Keep-alive
Keep-alive potential drop
350 V
At 150 uA