Abstract: A scanning radio receiver intended for use on the frequencies assigned to the Public Safety Radio Services and which is also operable for reception in the aircraft band from 118 MHz to 136 MHz. A ROM contains data establishing frequency limits and other information such that frequencies assigned to a number of service categories can be automatically searched in response to operation of service keys of a keyboard with the information storage requirements being minimized. For a service band having single frequencies or groups of frequencies which are not separated by fixed frequency increments, the data identifies the number of such frequencies or groups, the number of frequencies in each and a limit frequency of each. A processor outputs a frequency code to a frequency synthesizer while also processing input and stored data to develop the next code to be output.

Abstract: A strain detector comprises an oscillator having a surface acoustic wave delay line as its frequency control element. The delay line is constructed on a substrate, such as quartz which is disposed to distort in response to the strain to be measured. Distortion of the substrate alters the frequency control characteristics of the surface acoustic wave delay line with a consequent change in oscillator frequency. The change in frequency is proportional to the distortion of the substrate. A strain gage employs the detector output frequency as the input signal to a frequency measuring system.