DL68

Subminiature hearing-aid output pentode designed for approximately 22.5 V HT supplies. Its low-power construction supports miniature wearable audio equipment with limited battery voltage.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: Subminiature
Socket code: WIRE8
Base pins: 8
Nominal heater: 1.25 V / 25 mA

Description

Subminiature hearing-aid output pentode for 22.5 V HT supplies.

Socket description

Subminiature all-glass 8-wire lead family

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: Subminiature
Socket code: WIRE8
Base pins: 8
Nominal heater voltage: 1.25 V
Nominal heater current: 25 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

Subminiature - 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: 100000 Ω
Transconductance: 0.00043 S
Max plate voltage: 45 V
Max screen voltage: 45 V
Max plate dissipation: 0.1 W
Max screen dissipation: 0.025 W
Max cathode current: 2.3 mA

Published ratings and characteristics promoted from the approved German source.

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

1953 RFT Rundfunk Technik

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

HeaterVoltageNominal
1.25 V
Nominal
HeaterCurrentNominal
25 mA
Nominal
Maximum Plate Voltage
45 V
Maximum Screen Voltage
45 V
Maximum Plate Dissipation
0.1 W
Maximum Screen Dissipation
0.025 W
Maximum Cathode Current
2.3 mA

Data set 02

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

HeaterOrFilamentVoltage
1.25 V
HeaterOrFilamentCurrent
25 mA
Plate To Grid Capacitance
0.15 pF
Plate Voltage
22.5 V
Screen Voltage
22.5 V
Plate Current
600 uA
Screen Current
150 uA
Control Grid Voltage
-2.2 V
Transconductance
430 uS
Plate Resistance
100 kohm

Other

Load Resistance
37.5 kohm
ClassA
Power Output
5 mW
ClassA

Data set 03

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Anode voltage
22.5 V
ClassA
Screen-grid voltage
22.5 V
ClassA
Anode current
600 uA
ClassA
Screen-grid current
150 uA
ClassA
Control-grid voltage
-2.2 V
ClassA
Optimum load resistance
37.5 kOhm
ClassA