Abstract: An assembly is provided including two members capable of relative rotation about a common axis, and with electrical interconnections extending between the two members, the assembly, being for example, part of a gimbal system, wherein the electrical interconnections may be divided into two groups, selected such that, because of the voltages, and/or currents, carried by the electrical interconnections, it is desired that the electrical interconnections of one group are screened electrically from the electrical interconnections of the other group, by a screen which does not extend along the whole length of either group.

Abstract: A servo system 10 (FIG. 1) for positioning a sighting mirror 11 connected to a pulley 16 comprises a drive motor 13 rigidly connected to a drive pulley 15 in turn coupled by a tensioned drive belt to the pulley 16. Angular position of the motor or pulley 15 is measured by sensor 18 and passed by way of phase advance network 19 and amplifier 21 to produce an error signal for the drive motor. The pulley 16 is outside of the servo loop and any oscillations induced in the tensioned belt at its resonant frequency, possibly originating from electrical noise in the servo loop, will be uncontrollable.