UF85

Variable-mu or remote-cutoff pentode designed for RF, IF, broadband, or AVC-controlled receiver amplification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: B9A
Base pins: 9
Nominal heater: 19 V / 100 mA

Description

Variable-mu RF pentode for AM/FM IF, RF, and broadband amplifier service.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B9A
Base pins: 9
Nominal heater voltage: 19 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: 0.0061 S
Max plate voltage: 250 V
Max screen voltage: 250 V
Max plate dissipation: 2.5 W
Max screen dissipation: 0.65 W
Max cathode current: 15 mA

Variable-mu RF/IF pentode for AM/FM intermediate-frequency, RF, and broadband amplifier service.

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

1957 Philips Receiving and Amplifying Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate Voltage
170 V
Plate Current
9.7 mA
Screen Voltage
100 V
Screen Current
2.6 mA

Characteristic

Transconductance
5900 µS
Plate Resistance
300000 ohm

Data set 02

1963 Philips Electron Tubes Handbook V1

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Anode capacitance
3.2 pF
Control-grid capacitance
6.9 pF
Anode-to-control-grid capacitance
- to 0.007 pF
Maximum
Control-grid-to-heater capacitance
- to 0.15 pF
Maximum

Other

Plate voltage
100 V
RF/IF amplifier
Screen voltage
57 V
RF/IF amplifier; PlateVoltage=100V
Grid voltage
-1.1 V
RF/IF amplifier; PlateVoltage=100V
Plate current
5.5 mA
RF/IF amplifier; PlateVoltage=100V
Screen current
1.6 mA
RF/IF amplifier; PlateVoltage=100V
Plate voltage
170 V
RF/IF amplifier
Screen voltage
100 V
RF/IF amplifier; PlateVoltage=170V
Grid voltage
-2 V
RF/IF amplifier; PlateVoltage=170V
Plate current
9.7 mA
RF/IF amplifier; PlateVoltage=170V
Screen current
2.6 mA
RF/IF amplifier; PlateVoltage=170V
Plate voltage
200 V
RF/IF amplifier
Screen voltage
116 V
RF/IF amplifier; PlateVoltage=200V
Grid voltage
-2.3 V
RF/IF amplifier; PlateVoltage=200V
Plate current
11.4 mA
RF/IF amplifier; PlateVoltage=200V
Screen current
3.1 mA
RF/IF amplifier; PlateVoltage=200V

Characteristic

Transconductance
5000 uS
RF/IF amplifier; PlateVoltage=100V
Plate resistance
0.25 MOhm
RF/IF amplifier; PlateVoltage=100V
Transconductance
5900 uS
RF/IF amplifier; PlateVoltage=170V
Plate resistance
0.3 MOhm
RF/IF amplifier; PlateVoltage=170V
Transconductance
6100 uS
RF/IF amplifier; PlateVoltage=200V
Plate resistance
0.35 MOhm
RF/IF amplifier; PlateVoltage=200V

Data set 03

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Capacitances Ca
3.7 a
Capacitances Ca = 3,7 pF
Capacités ¢ _ 7.9 bR
7.9 a
Capacités ¢ _ 7.9 bR
— Capacitznces Ca
3.2 a
— Capacitznces Ca = 3,2 pF
}Input resistance at 100 lc/s
100 s
}Input resistance at 100 lc/s