| 摘要 |
PURPOSE:To equalize the loss characteristics of a transmission circuit automatically by using to pilot frequencies. CONSTITUTION:The output of an oscillator 1 of center frequency fB of a transmission band is transmitted to a transmitting circuit 7 together with a signal of multiplied frequency (fC=2fB) passed through waveform converting circuits 3 and 5 and a multiplying circuit 4. Those signals are passed through an equalizer 17 and a switching circuit 8 and separated by filters 10 and 12, and they are made into DC signals through full-wave rectifiers 11 and 13. Those signals are supplied to a comparator 14 to compare their levels with each other, and the level difference is made into a binary signal by a switching circuit 15. This binary signal is supplied to a logical circuit 16 to judge the necessary number of steps of the equalizer 17 and also perform necessary control. |
