AL2

Four-volt indirectly heated power pentode with published output operating characteristics. Designed for conventional receiver audio power amplification using a heater-cathode construction.

Directly heatedCold cathodeCommon cathodeDissimilar

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

Description

4 V indirectly heated 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: 1 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: 60000 Ω
Transconductance: 0.0025 S
Max plate voltage: 250 V
Max screen voltage: 250 V
Max plate dissipation: 9 W
Max screen dissipation: 1.5 W
Max cathode current: 50 mA

Audio output pentode; maximum ratings and a representative published operating point are promoted.

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
Plate current
36 mA
Screen voltage
250 V
Screen current
4 mA
Optimum load resistance
7000 ohm
Power output
3.8 W
Grid AC input voltage
14 V RMS
Maximum anode dissipation
9 W
Push-pull plate current
66 mA
PushPull
Push-pull screen current
7 mA
PushPull
Push-pull load resistance
6600 ohm
PushPull
Push-pull power output
11.5 W
PushPull

Characteristics

Transconductance
2600 µS
Plate resistance
60000 ohm

Data set 02

195X Tunsgram

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Typical plate voltage
250 V
Typical screen voltage
250 V
Typical plate current
36 mA
Typical control-grid voltage
-25 V
Output power
3.8 W
Single-ended published operating point
Load resistance
7000 Ohm
Single-ended published operating point

Data set 03

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Heater voltage
4 V
Heater current
1 A
Transconductance
2600 uS
Plate resistance
60000 ohm

Other

Plate voltage
250 V
ClassA
Screen voltage
250 V
ClassA
Grid voltage
-25 V
ClassA
Plate current
36 mA
ClassA
Screen current
5 mA
ClassA
Output power
3.8 W
ClassA
Load resistance
7000 ohm
ClassA