When space transmission of radio signals, including voice, is used under and in accord with authorization granted by the Federal Communications Commission to initiate any whistle, horn, bell, or other audible signaling device or voice conveyance; or when such transmission of radio signals, including voice, is used to activate or control any machine, material handling device, or other equipment hazardous to workers; the following shall apply:
(a) Single tone frequency shall not be used on radio equipment designed to initiate a whistle or other audible signal, or to activate or control any machine, material-handling device, or other device hazardous to workers.
(b) All adjustment, repair, or alteration of radio signaling devices shall be done only by or under the immediate supervision and responsibility of a person holding a first or second class commercial radio operator's license, either radio telephone or radio telegraph, issued by the Federal Communications Commission. All replacements parts shall be of such quality as to cause the unit to meet the minimum performance specifications outlined in Appendix A, Radio Control Signaling Devices.
(c) Equipment or machines being controlled by radio control devices shall be designed and built to fail/safe or stop in case of failure of the radio control device.
(d) When interference, overlap, fadeout, or blackout of radio signals is encountered, use of the radio control device shall be immediately discontinued and not resumed until the source of trouble has been detected and corrected.
(e) Two transmitters shall be in the visual or vocal vicinity of the rigging crew at all times. Spare transmitters shall be guarded against accidental activation.
(f) Two or more receivers on the same radio frequency with the same tone coding frequency is prohibited.
Exception : A second receiver may be used for monitoring provided it does not actuate or interfere with the primary receiver.A second receiver may be used for monitoring provided it does not actuate or interfere with the primary receiver.
3. Repealer of subsections (a)-(g), subsection relettering, and amendment of newly designated subsections (b) and (d) filed 10-24-01; operative 11-23-01 (Register 2001, No. 43).