CIRCUIT-TEST SWR/Watt Meter Model SWR-3P

Circa Mid 1990's to Early 2000's (ESTIMATED)

A compact analog testing device used to tune and maintain antenna systems for radio communication. This specific model is a re-branded version of a widely produced design also found under names such as WORKMAN, LODESTAR, and OPEC.

Use Case:

The meter is used to measure two primary parameters of a radio transmission system:

• Standing Wave Ratio (SWR): This indicates how efficiently a radio's power is transmitted into the antenna system. An ideal SWR is close to 1.0; readings over 3.0 can damage a transmitter. The user adjusts the "SET & F.S. ADJ" knob to calibrate the meter before reading the SWR on the top scale.

• RF Power Output: It measures the radio's forward power output in either 0-10 Watt or 0-100 Watt ranges, selectable via the front switch.

• Field Strength: An input labeled "ANT" allows a small whip antenna (usually included) to be connected for measuring the relative strength of the radio signal in the immediate vicinity.

Date of Manufacture:

The SWR-3P design has been a staple in the CB radio market for decades. While the original design likely dates back to the 1970s or 1980s, identical units are still being manufactured and sold new today under different brand names, making a specific date for any individual unit difficult to pinpoint.

Historical Significance:

The SWR-3P represents an iconic and enduring design in consumer radio accessories. Its historical significance lies in its affordability and simplicity, which made essential antenna tuning accessible to millions of CB (Citizens Band) radio enthusiasts during the peak of the CB radio craze in the 1970s and 80s. It is a foundational tool for anyone setting up a mobile or base station radio system, a design so effective that it has remained largely unchanged for nearly half a century.

(H-5.5cm x W-14.5cm x D-4cm)