VHF/UHF COMMUNICATIONS USING A SLOTTED COAXIAL CABLE.

Experiments conducted underground at Quirke Mine, Elliot Lake showed that ANDREW RADIAX slotted coaxial cables and a base station make communication possible between V. H. F. /U. H. F. portable radio-transmitters and between portable units and the base station. Excellent voice contact was possible all along a haulageway parallel to the cable but separated from it by about 30 feet of rock. The rf radiation penetrated the haulageway through manways and chutes. Best coverage was obtained using maximum available power (35 watts) into the cable from the base station in conjunction with 5-watt portable transmitters. Since the portable transmitters are a potential safety hazard, a combination of high-power base station and low-power portable units is a workable and safe arrangement.