Electrical Measurement of Communication Apparatus

This paper describes precision high-frequency measurements of a f u n d a m e n t a l type, special emphasis being placed on the measuring circuits rather than on the types of apparatus measured. Standards of frequency, resistance, capacitance, a n d inductance are discussed briefly. Bridge measurements are described for the measurement of frequency, inductance, effective resistance, capacitance, dielectric loss, capacitance balance a n d inductance balance. Circuits for the measurement of other high-frequency characteristics such as attenuation, gain, a n d cross-talk are included. INTRODUCTION L O N G D I S T A N C E electrical communication is now being effected by means of frequencies embracing the audible range and extending from there to the so-called short wave-lengths employed in radio transmission. According to the field of usefulness, this whole range has been subdivided into the audio, the carrier, and the radio ranges. From the viewpoint of the power engineer, all of the frequencies embraced in these ranges are high frequencies, b u t to the communication engineer, only those frequencies in the upper regions are considered high.