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AL5

Four-volt high-sensitivity power pentode with manufacturer-published output characteristics. Its comparatively high sensitivity permits useful audio power with reduced drive voltage.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: P35
Socket code: P8A
Base pins: 8
Nominal heater: 4 V / 2 A

Description

4 V high-sensitivity power pentode. Electrical ratings and operating characteristics were extracted from the supplied 4-volt valve data table, including the published heater data and available section-level values.

Socket description

European 8-pin side-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: P35
Socket code: P8A
Base pins: 8
Nominal heater voltage: 4 V
Nominal heater current: 2 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

P35 - 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

Plate resistance: 22000 Ω
Transconductance: 0.0085 S
Max plate voltage: 250 V
Max screen voltage: 275 V
Max plate dissipation: 18 W
Max screen dissipation: 3 W
Max cathode current: 90 mA

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

1938 Philips Miniwatt Vacuum Tube Catalog

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate voltage
250 V
Screen voltage
275 V
Screen current
7 mA
Optimum load resistance
3500 ohm
Power output
8.8 W
Grid AC input voltage
8.2 V RMS
Maximum anode dissipation
18 W
Push-pull plate current
130 mA
PushPull
Push-pull screen current
21 mA
PushPull
Push-pull load resistance
4500 ohm
PushPull
Push-pull power output
19.5 W
PushPull

Characteristics

Transconductance
8500 µS
Plate resistance
22000 ohm

Data set 02

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Heater voltage
4 V
Heater current
2 A
Transconductance
8500 uS
Plate resistance
22000 ohm

Other

Plate voltage
250 V
ClassA
Screen voltage
275 V
ClassA
Grid voltage
-14 V
ClassA
Plate current
72 mA
ClassA
Screen current
7 mA
ClassA
Output power
8.8 W
ClassA
Load resistance
3500 ohm
ClassA
Push-pull output power
19.5 W
PushPull;TwoTubes