the symbol pattern repeats every second. A fax machine running at 240 lines per minute can record the overall pattern of symbols. Such a chart will show 24 pulses on each line for a two channel system, forming columns down the page. Timing is very accurate with each symbol lasting the same time of 10.416666 ms. This is the duration for 96 baud elements. Software is available to receive and decode utility transmissions that use ARQ-M including Go2MONITOR, and there is also hardware such as the Code300-A from Hoka Electronic, and Wavecom M 4010. References Quantized radio modulation modes