1831 — Full-Wave High-Vacuum Rectifier

The 1831 is a full-wave high-vacuum rectifier valve designed specifically for use in alternating current (A.C.) mains receivers. It features a directly heated filament and is capable of handling high anode voltages while delivering a rectified direct current suitable for powering receiver circuitry.

Construction, Filament, and Physical Dimensions

The 1831 is constructed as a full-wave rectifier (also described as Vollweg Hochvakuum or Biplaque à vide poussé), containing two anode plates and a directly heated filament.

Filament Ratings

The filament is designed for direct heating and operates under the following nominal electrical conditions:

• Filament Voltage (Vf): 4.0 V
• Filament Current (If): Approximately 1.0 A

Physical Dimensions and Basing

The tube is equipped with an A35 base, with documentation referencing base connection S III (also designated as connection reference 5). The physical dimensions of the envelope are as follows:

• Maximum Overall Length (l): 145 mm (excluding pins)
• Maximum Diameter (d): 59 mm

Maximum Ratings

To ensure reliable operation and prevent damage to the valve, the operating conditions must be kept within the specified maximum ratings:

• Maximum A.C. Anode Voltage (Va max): 2 x 700 V RMS (no-load)
• Maximum Rectified Current (Ia max): 60 mA (D.C. current)

Operating Characteristics and Performance Curves

The performance of the 1831 rectifier is characterized by the relationship between the rectified output voltage (Va) and the delivered rectified current (Ia) across its operating range up to 64 mA. The output voltage behavior varies depending on the effective input voltage (Veff) applied to the anodes:

• At Veff = 2 x 700 V:
  • No-load output voltage (0 mA): ~980 V
  • Loaded output voltage at 60 mA: ~800 V
• At Veff = 2 x 600 V:
  • No-load output voltage (0 mA): ~840 V
  • Loaded output voltage at 60 mA: ~670 V
• At Veff = 2 x 500 V:
  • No-load output voltage (0 mA): ~700 V
  • Loaded output voltage at 60 mA: ~540 V

These values demonstrate the typical voltage regulation of the rectifier under load, showing a predictable drop in output voltage as the current demand increases from zero to the maximum rated limit of 60 mA.

Technical Summary

The 1831 is an A35-based, directly heated, full-wave high-vacuum rectifier valve designed for A.C. mains receivers. Utilizing a 4.0 V, 1.0 A filament, it supports a maximum A.C. anode voltage of 2 x 700 V RMS and delivers up to 60 mA of rectified D.C. current. Housed in a 145 mm by 59 mm envelope with an S III (reference 5) connection, the 1831 provides stable high-voltage rectification with well-defined output characteristics across input levels from 2 x 500 V to 2 x 700 V.