2028

Triode-heptode frequency changer combining oscillator and mixer functions for radio receivers. The triode provides local oscillation while the heptode supplies frequency conversion with comparatively strong conversion conductance.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: -
Base pins: -
Nominal heater: 6.3 V / 300 mA

Description

Triode-heptode for oscillator, mixer and RF/IF/NF service; source also lists 6AJ8, 2028, UCH81 and 19D8. Printed co-designation record duplicated from ECH81.

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: 6.3 V
Nominal heater current: 300 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

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.004 S
Amplification factor: 22
Max plate voltage: 250 V

Published ratings and characteristics promoted from the approved German source.

Section 2

Heptode

X-ray radiationInterelectrode capacitances

Plate resistance: 1000000 Ω
Transconductance: 0.000775 S
Max plate voltage: 250 V
Max screen voltage: 250 V

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

Triode

Application

Application
Oscillator text

SECTION 2

Heptode

Application

Application
MixerFrequencyConverter text