If you own the Mcmurdo Weather Receivers & AIS nav-7 then this is for you, showing you maintenance, testing, inspection, software download, updates plus much more, has 41 pages and all text & pictures are crisp and clear.
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NAV-7 supports reception of all three IMO NAVTEX frequencies and provides simultaneous channel monitoring of three channels. The 518 KHz English language service, 490 KHz national language and 4209.5 KHz long range services can be selected and viewed at the same time.