[Sydney]

Sounds to me like maybe the arm is not positioned properly along the resistor. If the positioning is correct, you should be within a couple of ohms of the 70-10. The total value of the resistor could be somewhat higher. That resistor could be made for several applications depending on the location of the little wiper. If the wiper arm can't be moved in a position to get 70-10 ohms, my guess is it isn't the right one.