Enhanced automatic line build out

A line build out circuit for equalizing signals from plural cables of different lengths, comprising:

• control voltage means for generating a control voltage indicative of the length of a cable to be traveled by a signal to be equalized;
• a tuning component having a variable characteristic, an anode and a cathode, said control voltage means being connected to said anode for applying the controlled voltage thereto for varying the variable characteristic;
• a capacitor connected to said anode;
• a resistor connected to said cathode;
• the signal to be equalized being applied over said resistor to said cathode and being measured at said cathode, the signal having a frequency roll-off representing a degree of attenuation which depends upon the frequency of the signal and upon the length of the cable over which the signal was supplied;
• and
• an equalizing amplifier connected to said cathode of said tuning component for amplifying the signal, said equalizing amplifier having an output, a peak detector connected to the output of said equalizing amplifier for measuring a voltage peak of the signal amplified by said equalizing amplifier, and an integrating amplifier connected between said peak detector and said tuning component anode for generating said control voltage, said peak detector and integrating amplifier forming said control voltage means.