The Type 1602-B U-H-F Admittance Meter is a simple, flexible instrument for the measurement of admittance and impedance over a wide frequency range. As a null instrument the U-H-F Admittance Meter can be used to measure the conductance and susceptance of an unknown circuit directly. It can also be used as a comparator to indicate equality of one admittance to another, or degree of departure of one from the other. As a direct indicating device, in addition, it can be used to determine the magnitude of the reflection coefficient on a 50-ohm coaxial line or the magnitude of an unknown impedance from ratios of output voltages read on a meter. When the admittance meter is used in conjunction with an adjustable- length coaxial line having a uniform characteristic impedance, such as the Type 874-LK20 Constant-lmpedance Adjustable Line, impedance and admittance measurements can be simplified as the correction for the length of transmission line between the unknown and the instrument can be eliminated. Also when the admittance meter is used with a wide-range balun of the proper type, such as the Type 874-UB Balun, accurate measurements can be easily made on balanced circuits over a wide frequency range. The instrument is best suited to measurements on coaxial-line circuits naving a 50-ohm characteristic impedance, but, in addition, measurements can be made on components or on coaxial-line circuits having characteristic impedances different from 50 ohms. The nominal frequency range of the instrument is from 40 to 1500 Me, but measurements can be made at frequencies as low as 10 Me. For admittance measurements using the null method, the magnitude of the conductive component of the unknown admittance is indicated directlv on a scale which ........... of the susceptive component is indicated on another scale which is calibrated from -20 to 0 to +20 millimhos. A third scale on the dial indicates the multiplier used which applies to both other scales. The multiplying-factor scale is calibrated from 1 to infinity. Therefore, theoretically, the instrument can measure admittances from zero to infinity; however, at either extreme the accuracy becomes poor because the dials cannot be read or set accurately. The instrument can also be used to advantage for matching a load to a line, as the instrument can be set up to indicate a matched condition when the output is zero; therefore, a continuous iqdication of the quality of the match is indicated by the output from the detector.