| 摘要 |
PURPOSE:To convert an optional input channel into an optional output channel by using a microprocessor so as to control the 1st and 2nd band pass filters and the 1st and 2nd local oscillators independently respectively. CONSTITUTION:In deciding an input channel and an output channel to be converted, its input/output channel data is read in a CPU by setting the data to a digital switch CH, the CPU gives a data commanding a local oscillation frequency in response to the input channel to the 1st local oscillator LOSC1 and a data commanding the pass band of the 1st BPF1 to the 1st D-A converter DA1 respectively according to the program in a ROM, gives the data commanding the local oscillating frequency in response to the output channel to the 2nd local oscillator LOSC2 and gives the data ommanding the pass bandof the 2nd BPF2 to the 2nd D-A converter DA2 respectively. Thus, the said local oscillators LOSC1, 2 and the D-A converters DA1,2 decide respective control voltage depending on the said data to lock the said local oscilloation frequencies f1, f2 and the pass band.
|
