DF668

Subminiature high-frequency pentode electrically similar to type 1AD4. Its compact construction supports fixed-gain RF signal amplification in miniature electronic equipment.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: WIRE8
Base pins: 8
Nominal heater: 1.25 V / 100 mA

Description

Subminiature high-frequency pentode, electrically similar to 1AD4.

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: -
Socket code: WIRE8
Base pins: 8
Nominal heater voltage: 1.25 V
Nominal heater current: 100 mA
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

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 350000 Ω
Transconductance: 0.0023 S
Max plate voltage: 110 V
Max screen voltage: 110 V
Max plate dissipation: 0.5 W
Max screen dissipation: 0.2 W

Published ratings and characteristics promoted from the printed technical data.

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
100 mA
Nominal
Maximum Plate Voltage
110 V
Maximum Screen Voltage
110 V
Maximum Plate Dissipation
0.5 W
Maximum Screen Dissipation
0.2 W

Characteristic

Transconductance
2300 µS
Typical
Plate Resistance
350000 ohm
Typical