DESCRIPTION:

The Bird Technologies 4028B3M Directional Power Sensor is a precision, high-power RF sensor engineered for directional forward and reflected power measurement across the 2.5 MHz to 4 MHz frequency band. It is part of Bird’s 4028 Series Precision RF Directional Power Sensors, designed for demanding test and calibration environments where tight measurement accuracy and long-term stability are required. 

The 4028B3M typically pairs with Bird multifunction power meters such as the 4421A Series, supporting accurate power analysis in high-power RF systems like industrial, communications, broadcast, and process-control applications. With a calibrated power range of 1.0 kW to 25 kW, this sensor delivers ±2 % accuracy at specified calibration frequency and power levels, with a slight performance variation outside calibration conditions. 

Calibration data (CALDATA) is included with each unit and is traceable to the National Institute of Standards and Technology (NIST), ensuring confidence in measurement integrity and repeatability. Designed for rugged field and bench use, the 4028B3M combines solid connectors and robust construction with high measurement precision. 

Typical Use Suitability:
Well suited for high-power RF monitoring, system commissioning, transmitter verification, and RF diagnosticswhere accurate, directional power data between 2.5 MHz and 4 MHz is critical — particularly in industrial and broadcast environments. 

Key Features

• Frequency Range: 2.5 MHz to 4 MHz 

• Power Range: 1.0 kW to 25 kW average 

• Accuracy: ±2 % at calibrated frequency and power levels; ±3 % outside calibration 

• Impedance: 50 Ohm nominal 

• VSWR: 1.05:1 maximum 

• Directivity:  28 dB 

• Connectors: 1-5/8 inch EIA flanged (sensor interface) 

• Calibration: NIST-traceable calibration data included