This manual provides the physical and functional description and operating theory necessary for effective use of the Telewave Model 44L1/L1P Broadband Radio Frequency (RF) Wattmeter. Its features include: • Displays five power ranges • Measures 1 to 500 watts • Does not require inserts • Does not require band switching • Fully operable in freezing conditions • Provides 5 watts full scale range • Interchangeable connectors (QC) • Lighweight, rugged and easy to carry • -40 dB RF sampling port (Model 44L1P) 2.02 The instrument integrates two broadband directional couplers for measuring incident and reflected power, ranging, calibration and display. The wide coverage and dynamic range of this instrument eliminates any inserts or band switching. A 20 uA taut band meter movement is used to display the measured power, providing the measurement accuracy necessary to tune low power portable transmitters. 2.03 A convenient, easy to read, voltage standing wave ratio (VSWR) chart is provided on the rear of the instrument for determining VSWR from the measured incident and reflected power levels. The instrument is designed for rugged field use and is housed in a diecast metal case with a leather carrying strap. The measurement circuits in the wattmeter are driven directly by the current developed in the coupler, making it unnecessary to supply AC power or batteries. A carrying case (Model TC44) is available as an option. The Model 44L1/L1P is ideally suited for mobile, marine, and aircraft applications as well as base stations.