John,Brett,Richard&Geoffrey
    Thanks for the "feedback" :). All I am trying to do is monitor a voltage in a feedback circuit from 40' from the circuit without affecting the performance of the feedback circuit. The monitored voltage goes to a LCD voltage display in my house.I think I will just try a follower with a resistor at the output , to prevent transient voltages from entering the feedback circuit from the shielded line.
regards
  Barry