[Code of Federal Regulations] [Title 47, Volume 5] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR80.257] [Page 71-72] TITLE 47--TELECOMMUNICATION COMMISSION (CONTINUED) PART 80_STATIONS IN THE MARITIME SERVICES--Table of Contents Subpart F_Equipment Authorization for Compulsory Ships Sec. 80.257 Manufacturing requirements for radiotelegraph automatic alarm receiver (auto alarm). (a) The auto alarm must consist of: (1) A radio receiver capable of receiving emissions of classes A1A, A1B, A2A, A2B, H2A, H2B, J2A, and J2B over the frequency range 496 through 504 kHz. (i) The receiver must reject signals +106 dB above one microvolt at +-150 kHz from the center frequency and +88 dB above one microvolt at +- 40 kHz from the center frequency. (ii) The receiver must respond to signals from 100 microvolts to 1 volt on the center frequency. There must be less than 6 dB variation in sensitivity from 496 kHz through 504 kHz. (2) A device capable of selecting the alarm signal specified under Sec. 80.259 (a) and (b). (3) A minimum of 3 audible alarm units to meet the three location installation requirements of Sec. 80.259(g). [[Page 72]] (4) A testing device to determine locally that the auto alarm system is operative. (b) The auto alarm may be constructed in one or more units but must be independent of the ship's regular radio receiving apparatus. (c) A telephone jack must be provided to permit reception by a telephone receiver. (d) Tuning and timing controls must not be accessible from the exterior of the device. (e) Once set into operation the audible alarms must continue to function until switches off in the principal radiotelegraph operating room. (f) A nonlocking or momentary-throw switch must be provided to permit temporary disconnection of the audible alarm on the bridge and in the operator's quarters when the auto alarm system is being tested. (g) A failure of the auto alarm power supply must activate the audible alarms. (h) The auto alarm must operate within specifications throughout the temperature range 0-50 degrees Celsius at relative humidities as high as 95%. (i) The auto alarm must be protected from excessive currents, power supply reversals and voltage variations which could cause damage to any component. (j) The auto alarm must be capable of operating when subjected to vibrations having a frequency between 20 and 30 Hertz and an amplitude of 0.76 mm (0.03 inch) in a direction at an angle of 30 to 45 degrees with the base of the auto alarm. [51 FR 31213, Sept. 2, 1986, as amended at 58 FR 44952, Aug. 25, 1993] Effective Date Note: At 68 FR 46966, Aug. 7, 2003, Sec. 80.257 was removed effective October 6, 2003.