TM 55-1930-209-14&P-17 Table 2-1.  Frequency/Channel Chart for Commercial Marine Radio in USA (continued) Channel TX frequency Rx frequency Channel assignment 67 156.375 156.375 Commercial intership 68 156.425 156.425 Noncommercial intership-ship/coast 69 156.475 156.475 Noncommercial intership-ship/coast 70 156.525 156.525 Noncommercial intership 71 156.575 156.575 Noncommercial intership-ship/coast 72 156.625 156.625 Noncommercial intership 73 156.675 156.675 Port operations-intership-ship/coast 74 156.725 156.725 Port operations-intership-ship/coast 77 156.875 156.875 Commercial intership 78 156.925 156.925 Noncommercial intership-ship/coast 79 156.975 156.975 Commercial intership-ship/coast 80 157.025 157.025 Commercial intership-ship/coast 81 157.075 157.075 US government only 82 157.125 157.125 US government only 83 157.175 157.175 US government only 84 157.225 161.825 Public - ship/coast 85 157.275 161.875 Public - ship/coast 86 157.325 161.925 Public - ship/coast 87 157.375 161.975 Public - ship/coast 88 157.425 157.425 Commercial intership NOTE Coordinate channel selection with other vessels requiring communication. Know    their    call    signs.        Channels    and    associated    transmit/receive frequencies are listed in Table 2-1. a. Verify that antenna lead and power leads are properly attached to radio set. b. Set radio power supply power switch to ON. c. Rotate OFF/VOLUME control clockwise to midposition on dial. d. Rotate squelch control fully counterclockwise. e. Set channel selector switch to desired channel. f. Rotate  squelch  control  clockwise  until  background  noise  disappears.    This  is  proper  squelch  setting.    Moving squelch control beyond this setting reduces the radio's ability to receive messages from distant stations. g. Set desired HI/LO power setting.  Switch should be in LO position when conditions permit.  Use HI position when radio contact can not be made on LO position or when considerable distance separates the radio sets. 2-17