UCH71

Series-heater triode-heptode for radio receivers, combining oscillator and frequency-converter functions. Manufacturer documentation also supports RF, IF, or AF amplification where appropriate.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B8G
Base pins: 8
Nominal heater: 20 V / 100 mA

Description

Triode-heptode for RF/IF/AF amplification and frequency conversion.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B8G
Base pins: 8
Nominal heater voltage: 20 V
Nominal heater current: 100 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: Yes

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

Max plate voltage: 175 V
Max plate dissipation: 0.5 W

Lorenz UCH71 indirectly heated 20 V, 100 mA series-heater triode-heptode for radio frequency conversion and additional AF amplification service. Oscillator triode may couple its grid to the third heptode grid or operate separately as RC-coupled AF voltage amplifier. Manufacturer limiting ratings for triode: maximum operating anode 175 V and plate dissipation 0.5 W; cold-anode voltage values are distinct from continuous limits. Oscillator dynamic transconductance around 0.44–0.45 mA/V at listed 100/200 V supply points is not the same as intrinsic static gm.

Section 2

Heptode

X-ray radiationInterelectrode capacitances

Max plate voltage: 250 V
Max plate dissipation: 1.5 W
Max cathode current: 15 mA

Lorenz UCH71 heptode section for mixer or IF-amplifier service; nominal 20 V, 100 mA series heater shared with oscillator triode. Manufacturer maximum operating anode 250 V, plate dissipation 1.5 W, cathode current 15 mA. Screen-grid ratings vary with operating anode current and the stated cold-grid voltage must not be promoted as a universal running screen limit. Mixing conversion conductance and IF amplifier slope are separate operating-mode characteristics.

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

1955 Lorenz

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Oscillator transconductance
0.00045 A/V
200VSupply