Data set 01
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Diode
Other
Average Diode Current
4 mA
EachDiode
Voltage - Triode (with diode, heptode or hexode) ·Diode-Diode-Triode
8CN7
Twin-diode high-mu triode designed as a television horizontal phase detector and reactance tube, integrating phase comparison and oscillator-frequency control.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 3
- Base
- 9EF
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 8.4 V / 225 mA
Description
The 8CN7 combines two diodes and a high-mu triode with separate cathodes for use as a horizontal phase detector and reactance tube in television receivers.
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
- 9EF
- Socket code
- B9A
- Base pins
- 9
- Nominal heater voltage
- 8.4 V
- Nominal heater current
- 225 mA
- Parallel heater voltage
- 4.2 V
- Parallel heater current
- 450 mA
- Series capable
- Yes
9EF - Terminal pinout
Electrical assignments shared by every tube using this base designation.
| Terminal | Section | Connection | Evidence |
|---|---|---|---|
| PIN1Base Pin | B | P — Plate (Anode) Original chart label: 2P; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN3Base Pin | B | G1 — Control Grid Original chart label: 2G1; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN4Base Pin | — | H — Heater Original chart label: H; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN5Base Pin | — | H — Heater Original chart label: H; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN6Base Pin | A | P — Plate (Anode) Original chart label: 1P; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN7Base Pin | A | G1 — Control Grid Original chart label: 1G1; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN8Base Pin | A | K — Cathode Original chart label: 1K; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
| PIN9Base Pin | B | K — Cathode Original chart label: 2K; manufacturer verification pending | Unverified EIA Base Connections, printed page 132, 9EF |
Section ratings
3 physical sections, each with unique specifications.
Section 1
Diode
X-ray radiationInterelectrode capacitances
- Max cathode current
- 5 mA
- Rectifier max heater-cathode voltage
- 200 V
- Rectifier warm-up time
- 11 s
Representative of two identical diode sections; 5 mA continuous current rating retained as parameter.
Section 2
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 58000 Ω
- Transconductance
- 0.0012 S
- Amplification factor
- 70
- Max plate voltage
- 300 V
- Max plate dissipation
- 1 W
- Rectifier max heater-cathode voltage
- 200 V
- Rectifier warm-up time
- 11 s
Published promoted fields populated semantically; identical repeated sections compressed.
Section 3
Diode
X-ray radiationInterelectrode capacitances
- Max cathode current
- 5 mA
Diode section 2; 5 mA maximum continuous current.
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 02
1966 Tung Sol Electronic Tubes 2 of 4
Published operating points and test conditions from this source.
SECTION 1
Diode
Other
Maximum_continuous_diode_current
5 mA
PhaseDetector
SECTION 2
Triode
Other
Plate_voltage
250 V
ClassA
Grid_voltage
-3 V
ClassA
Characteristic
Amplification_factor
70
ClassA
Plate_resistance
55000 ohm
ClassA
Transconductance
1200 uS
ClassA
Plate_current
1 mA
ClassA
SECTION 3
Diode
Other
Maximum_continuous_diode_current
5 mA
PhaseDetector
Data set 03
1968 General Electric Co
Published operating points and test conditions from this source.
SECTION 1
Diode
Other
Heater Voltage Series
8.4 V
Series
Heater Current Series
225 mA
Series
Heater Voltage Parallel
4.2 V
Parallel
Heater Current Parallel
450 mA
Parallel
MaximumContinuousDiodeCurrentEach
5 mA
EachDiode
Characteristic
Average Diode Current At5 V
20 mA
EachDiode;PlateVoltage=5V
SECTION 2
Triode
Characteristic
Plate Resistance
58000 Ohm
Transconductance
1200 uS
Amplification Factor
70