Digitally controlled analogue signal generating system - generates analog signals of varying frequency from digital values by adjustment of fundamental and read out frequencies

摘要

The appts. is used for the transmission of variable frequency signals over short wave communications links as digital signals and the generation of the appropriate analog. The appts. is used for storing and reading the individual values by means of a fixed time interval read out and a digital to analog converter. To generate analog signals (A) of frequency fn which are a multiple of a base frequency df, equidistant values are stored. The number of such values is proportional to the quotient of the read-out frequency (T) and the base frequency. The values are read out of the store (SP) sequentially. The reduction in required storage size is considerable, and is proportional to a factor dependent on the base frequency. For example, a reduction from 14400 places to 240 can be achieved.