Voltage Dual Tetrode ·Tetrode-Tetrode
15AB9
Twin tetrode designed for VHF RF amplification and autodyne mixer service, a heater-variant member of a television/radio front-end converter family.
- Sections
- 2
- Base
- -
- Socket code
- B10B
- Base pins
- 10
- Nominal heater
- 15 V / 150 mA
Description
15AB9 — Twin Tetrode Vacuum Tube
A twin tetrode receiving tube with a decal base, designed specifically for high-frequency applications including VHF amplification and VHF autodyne mixer service.
Overview
The 15AB9 is a specialized twin tetrode vacuum tube designed for operation in the Very High Frequency (VHF) spectrum. It is constructed with a decal base and houses two tetrode sections within a single envelope. The primary applications for this device are as VHF amplifiers and in VHF autodyne mixer circuits, where its dual-unit construction and high-frequency capabilities can be fully utilized.
The tube was produced by Matsushita Electronics Corporation of Takatsuki, Osaka, Japan. It is closely related to the 17AB9 vacuum tube, sharing identical physical and electrical characteristics with the exception of its heater parameters. The 15AB9 was registered under JEDEC release #4740A on April 19, 1965.
Heater Characteristics
The 15AB9 is designed with an indirectly heated cathode system. The electrical requirements for the heater are specified as follows:
| Parameter | Value |
|---|---|
| Heater Voltage | 15.0 V |
| Heater Current | 150 mA |
| Calculated Heater Power | 2.25 W |
The calculated heater power of 2.25 W is derived directly from the product of the nominal heater voltage (15.0 V) and the nominal heater current (0.15 A). This specific heater configuration is the primary distinguishing feature of the 15AB9 when compared to its sister design, the 17AB9.
Physical Construction and Base
The 15AB9 utilizes a decal base configuration. This multi-pin base design provides the necessary independent connections for the electrodes of the twin tetrode structure, ensuring proper isolation and connection stability at high frequencies. The internal construction features two tetrode sections, which are optimized to minimize interelectrode coupling and feedback, making the tube highly suitable for stable amplification in the VHF band.
Related Designations and Comparisons
The 15AB9 is electrically and physically identical to the 17AB9 (originally registered under JEDEC Release No. 4740 on June 29, 1964), except for the heater voltage and current ratings. Because of this identity in active electrode structure, the two tubes share the same internal capacitances, transconductance, plate resistance, and RF performance characteristics. However, due to the different heater requirements, they are not direct plug-in substitutes without modifying the heater supply circuit of the host equipment.
RF Applications and Circuit Function
The 15AB9 is engineered for two primary roles in VHF receiver and transmitter stages:
- VHF Amplifiers: The tetrode configuration of each section provides a screen grid that significantly reduces the grid-to-plate capacitance. This reduction in feedback capacitance allows for stable, high-gain amplification at very high frequencies without the neutralization circuits often required by triodes.
- VHF Autodyne Mixers: In autodyne mixer service, the tube sections can be configured to simultaneously perform the functions of a local oscillator and a mixer. This allows for efficient frequency conversion in VHF receivers, reducing the overall component count and space requirements of the RF front-end.
Socket description
Decal 10-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B10B
- Base pins
- 10
- Nominal heater voltage
- 15 V
- Nominal heater current
- 150 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
Tetrode
- Plate resistance
- 110000 Ω
- Transconductance
- 0.01 S
- Max plate voltage
- 250 V
- Max screen voltage
- 180 V
- Max plate dissipation
- 2 W
- Max screen dissipation
- 0.5 W
- Max cathode current
- 20 mA
Matsushita 15AB9 first of two physical VHF RF amplifier/autodyne mixer tetrodes, 15 V 0.15 A heater. Other electrical specifications from manufacturer's stated JEDEC 6AB9 twin-tetrode equivalence. Each unit maximum plate 250 V, screen supply 180 V, plate dissipation 2 W, screen dissipation 0.5 W, cathode 20 mA; both plates together maximum 3.5 W. Typical each at 125 V plate, 80 V screen: gm 10 mA/V and plate resistance 110 kΩ. Interelectrode capacitances supplied by JEDEC.
Section 2
Tetrode
- Plate resistance
- 110000 Ω
- Transconductance
- 0.01 S
- Max plate voltage
- 250 V
- Max screen voltage
- 180 V
- Max plate dissipation
- 2 W
- Max screen dissipation
- 0.5 W
- Max cathode current
- 20 mA
Second physical tetrode of Matsushita 15AB9 twin tetrode, electrically equivalent to the corresponding 6AB9 sections aside from 15 V 150 mA heater. Typical each-unit Va 125 V, screen 80 V, Vg1 -1 V, 8 mA plate, 2 mA screen, gm 10 mA/V and rp approximately 110 kΩ. Per-unit limits plate 250 V, screen supply 180 V, plate dissipation 2 W, screen dissipation 0.5 W, cathode 20 mA. IMPORTANT total dissipation for both plates must not exceed 3.5 W. JEDEC 6AB9 reference gives interelectrode capacitances.
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.