Data set 01
1961 Tung Sol
Published operating points and test conditions from this source.
SECTION 1
Triode
Other
Service
Series regulator
DCPowerSupply
Power - Triode ·Triode-Triode
5998A
Low-mu twin power triode designed for series-regulator service in DC power supplies. Electrically related to the 5998 but using a different envelope and base, it emphasizes high current and very low plate resistance.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 2
- Base
- 8BD
- Socket code
- IO
- Base pins
- 8
- Nominal heater
- 6.3 V / 2.4 A
Description
The 5998A is a low-mu twin triode for series-regulator service in DC power supplies; electrically it is the same as the 5998 but uses a different envelope and base.
Socket description
International Octal
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- 8BD
- Socket code
- IO
- Base pins
- 8
- Nominal heater voltage
- 6.3 V
- Nominal heater current
- 2.4 A
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
8BD - Terminal pinout
Electrical assignments shared by every tube using this base designation.
| Terminal | Section | Connection | Evidence |
|---|---|---|---|
| PIN12G1 | B | G1 — Control Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN22P | B | P — Plate (Anode) EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN32K | B | K — Cathode EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN41G1 | A | G1 — Control Grid EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN51P | A | P — Plate (Anode) EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN61K | A | K — Cathode EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN7H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
| PIN8H | — | H — Heater EIA transcription; manufacturer confirmation pending | Unverified EIA Base Connections, printed page 129, 8BD |
Section ratings
2 physical sections, each with unique specifications.
Section 1
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 350 Ω
- Transconductance
- 0.0155 S
- Amplification factor
- 5.4
- Max plate voltage
- 275 V
- Max plate dissipation
- 15 W
- Max cathode current
- 140 mA
- Rectifier max heater-cathode voltage
- 100 V
Representative section for two electrically identical sections.
Section 2
Triode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 350 Ω
- Transconductance
- 0.0155 S
- Amplification factor
- 5.4
- Max plate voltage
- 275 V
- Max plate dissipation
- 15 W
- Max cathode current
- 140 mA
Second physical triode section; identical dual-triode structure per reviewed datasheets.
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 4 of 4
Published operating points and test conditions from this source.
SECTION 1
Triode
Characteristic
Grid-to-plate capacitance each section
14.5 pF
WholeTube
Input capacitance each section
6.5 pF
WholeTube
Output capacitance each section
2 pF
WholeTube
Heater-to-cathode capacitance each section
11 pF
WholeTube
Plate-to-plate capacitance between sections
2 pF
WholeTube
Other
Maximum plate voltage
275 V
WholeTube
Maximum plate dissipation
15 W
WholeTube
Maximum DC plate current
140 mA
WholeTube
Maximum heater-cathode voltage
100 V
WholeTube
Plate supply voltage
110 V
AverageCharacteristics
Cathode-bias resistor
105 ohm
AverageCharacteristics
Amplification factor
5.4
AverageCharacteristics
Plate resistance
350 ohm
AverageCharacteristics
Transconductance
15500 uS
AverageCharacteristics
Plate current
100 mA
AverageCharacteristics