ribbon conductors overlap wound over the dielectric material 88 so as to compress the dielectric material and so as to provide a flexible outer conductor which makes the transmitter cable easier to manipulate and pass along narrow and tortuous passageways in arteries and the like as shown most clearly in fig7 the outer conductor can be considered to be overlap wound in two directions the first or lower layer being wrapped in overlapping layers toward the right as shown in fig7 and the upper or outer layer being wrapped in overlapping layers progressing to the left as shown in fig7 fig7 depicts the outer conductor overlap windings as they would be formed about the proximal end of the transmitter cable the first winding 92 being placed flat against the dielectric material 88 subsequent windings extending to the right over the dielectric material 88 overlap a respective immediately preceding winding and compress the dielectric material the last winding on the lower layer also contacts the dielectric material after which subsequent windings progressing in the opposite direction to the left as shown in fig7 overlap the respective immediately preceding winding and also cover the immediately underlying windings on the first layer the windings on the second layer continue until the first winding 92 is reached at which point the windings in the second layer are terminated and fixed to prevent unwinding of the outer conductor the outer conductor 90 is preferably formed approximately 0 005 inches by 0 0015 inches the use of this coil material for the outer conductor arranged in the described manner provides a thin flexible and appropriately.