Power - Triode ·Triode
Directly heated low-load-resistance power-amplifier triode retained as a replacement type for older Sparton receivers. Published Class A operation uses about 250 V plate supply and provides approximately 1.8 W output.
The 183 (also designated as 183/483) is a filament-type power triode designed for Class A audio power amplification. It features a coated filament and is intended for use in the output stage of AC-operated radio receivers. The tube is characterized by a low amplification factor, low plate resistance, and the ability to deliver moderate power output under Class A1 operating conditions.
The 183 is constructed with an ST-14 glass bulb envelope and a medium 4-pin base. The physical dimensions of the tube are:
The tube utilizes a 4D bottom-view base connection. The pin assignments are:
The 183 features a directly heated, coated filament designed for either AC or DC operation. The filament specifications are:
The 183 is rated for a maximum plate voltage of 250 V. Under typical Class A (or Class A1) amplifier service, the tube is operated with a plate voltage of 250 V and a negative grid bias of 60 V. Depending on the specific operating point, the typical characteristics vary slightly:
| Parameter | Operating Point A | Operating Point B |
|---|---|---|
| Plate Voltage | 250 V | 250 V |
| Grid Voltage | -60 V | -60 V |
| Plate Current | 30 mA | 25 mA |
| Plate Resistance | 1,750 Ω | 1,800 Ω |
| Transconductance | 1,700 µmhos | 1,800 µmhos |
| Amplification Factor (μ) | 3.0 | 3.2 |
| Load Resistance | — | 4,500 Ω |
| Power Output | — | 2.0 W |
At these operating points, the low amplification factor (3.0 to 3.2) and low plate resistance (1,750 to 1,800 Ω) are typical of early power triodes designed to drive electromagnetic speakers through a suitable output transformer. Under the second set of conditions, with a load resistance of 4,500 Ω, the tube delivers a power output of 2.0 W.
Interelectrode capacitances (input, output, and grid-to-plate) are not specified in the historical documentation.
The 183 (or 183/483) is a classic filament-type power triode housed in an ST-14 glass envelope with a medium 4-pin base. Operating with a 5.0 V, 1.25 A filament supply, it is designed for Class A power amplifier service, particularly in the output stages of AC-operated receivers. With a maximum plate voltage rating of 250 V, it typically operates at this limit with a -60 V grid bias, providing an amplification factor of approximately 3.0 to 3.2, a plate resistance of 1,750 to 1,800 Ω, and a power output of 2.0 W into a 4,500 Ω load.
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Promoted from printed maximum-rating/characteristic columns; additional published values retained in TUBE_SECTION_PARAMETER.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Plate Resistance
1750 ohm
Transconductance
1700 µS
Amplification Factor
3
Plate Voltage
250 V
Grid Voltage
-60 V
Plate Current
30 mA
Load Impedance
5000 ohm
Power Output
1.8 W
Data set 02
Published operating points and test conditions from this source.
Plate Voltage
250 V
ClassA
Grid Voltage
-60 V
ClassA
Plate Current
30 mA
ClassA
Data set 03
Published operating points and test conditions from this source.
Service
Power amplifier