YL1240

VHF double tetrode containing two identical RF power sections for mobile Class C amplification, oscillation, and frequency multiplication. The paired structure permits balanced or combined transmitter operation while retaining compact size and moderate plate dissipation.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: -
Nominal heater: -

Description

The Mullard YL1240 is a single-ended VHF double tetrode for mobile Class C amplifier, oscillator 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: -
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

2 physical sections, each with unique specifications.

Section 1

Tetrode

X-ray radiationInterelectrode capacitances

Max plate voltage: 450 V
Max plate dissipation: 10 W

Representative of two identical RF-power tetrode sections.

Section 2

Tetrode

X-ray radiationInterelectrode capacitances

Max plate voltage: 450 V
Max plate dissipation: 10 W

Second physical tetrode section; added to align double-tetrode construction with SectionCount=2.

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 Mullard

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

Maximum Operating Frequency
200 MHz
Maximum Plate Voltage
450 V
Maximum Plate Dissipation
10 W
EachSection
RF Output Power
33 W
RepresentativePublishedMaximum
RF Output Power
22 W
ClassC; CCS; 200MHz
RF Output Power
33 W
ClassC; ICAS; 200MHz
Plate Voltage
450 V
ClassC; ICAS; 200MHz
Plate Current
56 mA
EachSection; ClassC; ICAS
Screen Voltage
200 V
ClassC; ICAS
Frequency Tripler Output Power
12 W
174MHzOutput; 58MHzInput