50FK5

High-transconductance audio power pentode for transformerless equipment, providing about 1.2 W from a 110 V supply.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7CV
Socket code: B7G
Base pins: 7
Nominal heater: 50 V / 100 mA

Description

Audio-output power pentode. The supplied datasheet provides maximum ratings and representative Class A operating characteristics for receiver/audio output applications.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7CV
Socket code: B7G
Base pins: 7
Nominal heater voltage: 50 V
Nominal heater current: 100 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7CV - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G3	A	G3 — Suppressor GridGroup 7CV1 EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN1K	A	K — CathodeGroup 7CV1 EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN2G1	A	G1 — Control Grid EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN3H	—	H — Heater EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN4H	—	H — Heater EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN5G1	A	G1 — Control Grid EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN6G2	A	G2 — Screen Grid EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV
PIN7P	A	P — Plate (Anode) EIA chart transcription; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CV

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 14000 Ω
Transconductance: 0.0128 S
Max plate voltage: 160 V
Max screen voltage: 130 V
Max plate dissipation: 5.5 W
Max screen dissipation: 1.75 W

Promoted from published ratings/characteristics tables; additional published values retained in TUBE_SECTION_PARAMETER.

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater voltage
50 V
Heater current
100 mA
Plate supply voltage
110 V
ClassA1
Screen supply voltage
115 V
ClassA1
Maximum signal power output
1.2 W
ClassA1

Capacitance

Grid-to-plate capacitance
0.66 pF
Input capacitance
17 pF
Output capacitance
9 pF

Data set 02

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Typical plate voltage
110 V
ClassA
Typical screen voltage
115 V
ClassA
Zero-signal plate current
32 mA
ClassA
Load resistance
3000 ohm
ClassA
Maximum-signal power output
1.2 W
ClassA
Maximum plate voltage
150 V
PromotedValue
Maximum screen voltage
130 V
PromotedValue
Maximum plate dissipation
5.5 W
PromotedValue
Maximum screen dissipation
1.75 W
PromotedValue
Plate Voltage
150 V
PublishedTable
Grid #2 Input
175 W
PublishedTable
Cathode Resistor
62 ohm
PublishedTable
Peak Af Grid #1 Voltage
3 V
PublishedTable
Zero- Signal Plate Current
32 mA
PublishedTable
Max.-Signal Plate Current
32 mA
PublishedTable
Max.-Signal Grid #2 Current
12 mA
PublishedTable
Plate Resistance (Approx.)
14000 ohm
PublishedTable
Tr Ansconductance
12800 ΜMHOS
PublishedTable
Total Harmonic Distortion
8 %
PublishedTable
Max.-S16N Al Power Output
1.2 W
PublishedTable

Characteristics

Plate resistance
14000 ohm
PromotedValue
Transconductance
0.0128 A/V
PromotedValue
Grid #I To Plate
0.65 pF
PublishedTable
Grid #1 To Cathode H Grid #3, Heater & Grid #2
17 pF
PublishedTable
Slate To Cathode # Grid #3, Heater 6 Grid #2
9 pF
PublishedTable