Weston Model 301 Rectifier Type Decibel Panel Meter 6mW 500 Ohm Zero Power Level

Weston Model 301 Rectifier Type Decibel Panel Meter 6mW 500 Ohm Zero Power Level

The Weston Model 301 is a rectifier type panel meter scaled in decibels (dB), designed to measure audio signal levels relative to a defined zero power level reference. The face reads from -10 to +6 dB, with a zero power level calibrated at 6 milliwatts into 500 ohms — a standard reference point used in professional audio and telephone transmission systems. The 1.73V reference voltage is printed on the scale. This is a square-format panel-mount instrument with a single pointer movement, a zero-adjust knob on the front panel, and two brass binding post terminals on the rear.

Specifications & What's Included

• Brand: Weston Electrical Instrument Corporation
• Model: 301
• Type: Rectifier Type Panel Meter
• Instrument Subtype: Type 60
• Scale: Decibels (dB), –10 to +6 dB
• Zero Power Level Reference: 6 Milliwatts, 500 Ohms
• Reference Voltage: 1.73V (printed on dial face)
• Movement: Rectifier type (D'Arsonval movement with rectifier for AC/audio measurement)
• Terminals: Two brass binding posts on rear
• Housing: Square black Bakelite panel-mount case
• Front panel: Single pointer, zero-adjust screw/knob at bottom center
• Dial face: Aged/yellowed with normal spotting; all graduations and text legible
• Meter only — no mounting hardware or cables included

Applications

Rectifier type dB panel meters like the Weston Model 301 were standard instruments in mid-20th-century audio engineering, telephone network transmission, and broadcast studios. The 6 mW / 500-ohm zero power level (0 dBm at 600 ohms was the related standard) was a widely used reference in telephony and audio distribution, making these meters the primary tool for setting and monitoring signal levels on mixing consoles, patch bays, transmission lines, and broadcast equipment. Weston Electrical was one of the leading American meter manufacturers of the era, and their panel meters were found in telephone company facilities, radio broadcast stations, recording studios, and early television production equipment throughout the 1930s through the 1960s. Today these meters are sought by vintage audio restorers, collectors of antique test instruments, and technicians maintaining or rebuilding period broadcast and communications equipment. They are also used decoratively in studio builds aiming for a period-correct look.