| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital FPU(field pickup unit) transmitter and a digital FPU, receiver that can solve a problem of a limited small range of the length of a coaxial cable interconnecting a control section and a high-frequency section and coping with changes in the frequency characteristics without adjustment, because conventional FPU transmitter/receiver has needed manual adjustment for the change in the frequency characteristics, even though fluctuations in a power supply voltage and a level of an IF signal can be corrected automatically in the case of change in the length L of the coaxial cable. SOLUTION: A control section 101 of the FPU transmitter is provided with a level correction circuit 110, that can adjust a signal level by a control signal and with a variable equalizer circuit 111 that adjusts frequency characteristics. A high-frequency section of the FPU transmitter 102 is provided with a voltage detection circuit 26 that detects drop in a DC voltage applied to a coaxial cable 3. A 1st arithmetic unit 19 reads a cable length and an equalizer characteristic to be corrected from data having been stored in advance, on the basis of detected voltage data and decides them so as to control the variable equalizer circuit 111 and the level correction circuit 110. |
