7FC7

Frame-grid double triode designed for cascode RF amplification to approximately 220 MHz, combining two high-frequency sections for VHF receiver and television front-end service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B9A
Base pins: 8
Nominal heater: 7.2 V / 300 mA

Description

The 7FC7 is a frame-grid double triode intended for cascode RF amplification at frequencies up to about 220 MHz and is electrically equivalent to the 6FC7 except for heater ratings.

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: 8
Nominal heater voltage: 7.2 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: 0.012 S
Max plate voltage: 130 V
Max plate dissipation: 1.8 W
Max cathode current: 22 mA

Grounded-cathode cascode input section, pins 6, 7, 8 and 9, with pins 7 and 8 recommended strapped per Tung-Sol. Frame-grid dual triode for cascode amplifier operation up to 220 MHz; each section rated 130 V plate voltage, 1.8 W plate dissipation and 22 mA cathode current.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.012 S
Max plate voltage: 130 V
Max plate dissipation: 1.8 W
Max cathode current: 22 mA

Grounded-grid cascode output section, pins 1, 2 and 3, per Tung-Sol. Frame-grid dual triode for cascode amplifier operation up to 220 MHz; each section rated 130 V plate voltage, 1.8 W plate dissipation and 22 mA cathode current. Published transconductance 12,000 µmhos at specified test conditions.

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

Triode

Application

Maximum Frequency
220 MHz

Construction

FrameGridConstruction
1

Data set 02

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate_voltage
40 V
Section1,Section2,Cascode
Grid_voltage
-1.2 V
Section1,Section2,Cascode
Noise_factor
4.5 dB
Section1,Section2,Cascode

Characteristic

Plate_current
1.5 mA
Section1,Section2,Cascode
Transconductance
12000 uS
Section1,Section2,Cascode

Capacitance

Grid-to-plate capacitance
1.4 pF
Section1,Section2
Input capacitance
6.3 pF
Section1,Section2
Output capacitance
4.5 pF
Section1,Section2
Cathode-to-heater capacitance
2.9 pF
Section1,Section2