The receiver is of the double superhet architecture and operates from an aerial input (via a SAW filter) to bitstream output to CT2 format, whilst the transmitter operates from I/Q inputs to +13dBm at the final frequency. A single (external) frequency reference is all that is required to give full coverage over the range of 800 to 1000MHz.The on-off slope of the Transmit PAis governed internally to give the required switch-on ramp, whilst the output can be swiched from low to high power by means of an external digital control signal. The channelselect is controlled from a digital serial input, and allows continuous channel control from 800 to 1000MHz.