Data set 01
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Heptode
Characteristic
Conversion Transconductance
950 uS
Other
Service
Converter / oscillator-mixer
Voltage Radio Detector Converter ·Heptode
12BA7
Heptode oscillator-mixer for superheterodyne frequency conversion. It combines local oscillator and mixer action in one multi-grid structure with comparatively strong conversion performance for radio receiver front ends.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- 8CT
- Socket code
- B9A
- Base pins
- 9
- Nominal heater
- 12.6 V / 150 mA
Description
THE 126A7 IS A CATHODE TYPE HIGH GAIN PENTAGRID CONVERTER IN THE SMALL J-PIN BUTTON CONSTRUCTION. IT IS DESIGNED FOR SERVICE AS A COMBINED LOCAL OSCILLATOR AND MIXER AT HIGH FREQUENCIES, ESPECIALLY IN THE FM BROADCAST BAND.
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
- 8CT
- Socket code
- B9A
- Base pins
- 9
- Nominal heater voltage
- 12.6 V
- Nominal heater current
- 150 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
8CT - Terminal pinout
Electrical assignments shared by every tube using this base designation.
| Terminal | Section | Connection | Evidence |
|---|---|---|---|
| PIN1G2 | A | G2 — Screen GridGroup 8CT1 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN1G4 | A | G4 — Fourth GridGroup 8CT1 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN2G1 | A | G1 — Control Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN3K | A | K — Cathode EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN4H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN5H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN6G5 | A | G5 — Fifth GridGroup 8CT6 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN6IS | A | IS — Internal ScreenGroup 8CT6 EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN7G3 | A | G3 — Suppressor Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN8IS | A | IS — Internal Screen EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
| PIN9P | A | P — Plate (Anode) EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8CT |
Section ratings
1 physical section, each with unique specifications.
Section 1
Heptode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 1000000 Ω
- Transconductance
- 0.00095 S
- Amplification factor
- 165
- Max plate voltage
- 300 V
- Max screen voltage
- 150 V
- Max plate dissipation
- 2 W
- Max screen dissipation
- 0.6 W
- Max cathode current
- 22 mA
Heptode section; ratings and characteristics retained in parameter rows where not safely promotable.
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
Heptode
Capacitance
GRID ii
70 pF
Published datasheet; operating column 1
GRID ii
3.3 pF
Published datasheet; operating column 2
Other
Gi TO (F1f GZy1Gg}G3}GS}P}IS)
3.4 pF
Published datasheet
K TO (H}GZhGg}G3}GS}P}IS)
4 pF
Published datasheet
RF INPUT; G~ TO (M}K}Gi}GZ6Gg}GS}P}IS)
9.5 pF
Published datasheet
MIXER
0 pF
Published datasheet; operating column 1
MIXER
8.3 pF
Published datasheet; operating column 2
MAXIMUM HEATER —CATHODE VOLTAGE
90 V
Published datasheet
MAXIMUM PLATE VOLTAGE
300 V
Published datasheet
MAXIMUM GRIDS /
2 V
Published datasheet; operating column 1
MAXIMUM GRIDS /
6 V
Published datasheet; operating column 2
MAXIMUM GRIDS /
44 V
Published datasheet; operating column 3
MAXIMUM GRIDS k2
6 V
Published datasheet; operating column 1
MAXIMUM GRIDS k2
300 V
Published datasheet; operating column 2
MAXIMUM NEGATIVE GRID
43 V
Published datasheet
MAXIMUM POSITIVE GRID i1
3 V
Published datasheet; operating column 1
MAXIMUM POSITIVE GRID i1
0 V
Published datasheet; operating column 2
MAXIMUM GRID
15 V
Published datasheet; operating column 1
MAXIMUM GRID
0 V
Published datasheet; operating column 2
MAXIMUM PLATE DISSIPATION
2 W
Published datasheet
MAXIMUM GRIDS M2
6 W
Published datasheet; operating column 1
MAXIMUM GRIDS M2
4 W
Published datasheet; operating column 2
MAXIMUM GRIDS M2
1.5 W
Published datasheet; operating column 3
MAXIMUM CATHODE CURRENT
22 mA
Published datasheet
CONVERSION TRANSC
0 uS
Published datasheet; operating column 1
CONVERSION TRANSC
900 uS
Published datasheet; operating column 2
CONVERSION TRANSC
950 uS
Published datasheet; operating column 3
CONNECTED TO PLATE B
0 uS
Published datasheet
EC2 b EC4 =
100 V
Published datasheet
Ecs =
0 V
Published datasheet
~ Ecs =
0 V
Published datasheet
Rq! =
20 ohm
Published datasheet; operating column 1
Rq! =
0 ohm
Published datasheet; operating column 2
o. .--I c =
0.1 V
Published datasheet; operating column 1
o. .--I c =
12.6 V
Published datasheet; operating column 2
Characteristic
HEATER VOLTAGE
12.6 V
Published datasheet
HEATER VOLTAGE
126 V
Published datasheet; operating column 1
NEATER CURRENT LSO
150 mA
Published datasheet
PLATE VOLTAGE LOO
250 V
Published datasheet
GRID rE3 VOLTAGE
-1 V
Published datasheet; operating column 1
PLATE CURRENT
3.6 mA
Published datasheet; operating column 1
PLATE CURRENT
3 mA
Published datasheet; operating column 2
GRIDS !
2 mA
Published datasheet; operating column 1
GRIDS !
6 mA
Published datasheet; operating column 2
GRIDS !
4 mA
Published datasheet; operating column 3
TOTAL CATHODE CURRENT
1 mA
Published datasheet; operating column 1
TOTAL CATHODE CURRENT
2 mA
Published datasheet; operating column 2
GRID N3 VOLTAGE
0 V
Published datasheet
GRID ki VOLTAGE
0 V
Published datasheet
PLATE CURRENT
32 mA
Published datasheet
current of
0.35 mA
Published datasheet
Data set 03
1971 RCA HB3 Binder 5 of 7
Published operating points and test conditions from this source.
SECTION 1
Heptode
Other
Current
300 mA
Capacitance
(RF Input)
9.5 pF
(Mixer Output)
8.3 pF
(Osc. Input)
6.7 pF
Grid No. to Plate max
3 pF
PublishedColumn1
Grid No. to Plate max
0.19 pF
PublishedColumn2
Grid No. to Grid No.l max
3 pF
PublishedColumn1
Grid No. to Grid No.l max
0.1 pF
PublishedColumn2
Grid No.l to Plate max
0.05 pF
Except Cathode
3.4 pF
Grid No.l to Cathode
3.3 pF
Except Grid No.i
4 pF
PLATE VOLTAGE D max
3 V
PublishedColumn1
PLATE VOLTAGE D max
0 V
PublishedColumn2
GRID-No. d INTERNAL-SHIELD VOLTAGE max
5 V
PublishedColumn1
GRID-No. d INTERNAL-SHIELD VOLTAGE max
0 V
PublishedColumn2
GRIDS-No. d No. VOLTAGE max
4 V
PublishedColumn1
GRIDS-No. d No. VOLTAGE max
100 V
PublishedColumn2
GRIDS-No. d No. SUPPLY VOLTAGE max
4 V
PublishedColumn1
GRIDS-No. d No. SUPPLY VOLTAGE max
300 V
PublishedColumn2
PLATE DISSIPATION max
2 W
GRIDS-No. No. DISSIPATION max
4 W
PublishedColumn1
GRIDS-No. No. DISSIPATION max
1.5 W
PublishedColumn2
TOTAL CATHODE CURRENT max
22 mA
Negative bias value max
100 V
Positive bias value max
0 V
Heater negative with respect to cathode. max
90 V
Heater positive with respect to cathode. max
90 V
Plate Voltage
100 V
PublishedColumn1
Plate Voltage
250 V
PublishedColumn2
Grids-No. & No. (Screen) Voltage
100 V
PublishedColumn1
Grid-No. (Control Grid) Voltage
-1 V
PublishedColumn1
Grid-No.l (Cscillator Grid) Resistor
20000 ohm
PublishedColumn1
Plate Resistance (Approx.)
0.5 Mohm
PublishedColumn1
Plate Resistance (Approx.)
1 Mohm
PublishedColumn2
Conversion Transconductance
900 µS
PublishedColumn1
Conversion Transconductance
950 µS
PublishedColumn2
Plate Current
3.6 mA
PublishedColumn1
Plate Current
3.8 mA
PublishedColumn2
Grids-No. & No. Current
10.2 mA
PublishedColumn1
Grids-No. & No. Current
10 mA
PublishedColumn2
Grid-No.l Current
0.35 mA
PublishedColumn1
Total Cathode Current
14.2 mA
PublishedColumn1
zero Dias; grids—No. and xo.n and plate at
2 V
PublishedColumn1
zero Dias; grids—No. and xo.n and plate at
300 V
PublishedColumn2
Characteristics
Heater voltage nominal
12.6 V
Heater current
150 mA