Point Reyes NAVTEX station NMC ($12C) is part of US Coast Guard communication service established in 1924.
NMC broadcast navigation and marine safety messages on 518 KHz during thirty-minutes time slots past 0000, 0400, 0800, 1200, 1600 and 2000 UTC.
While the intended coverage of NMC is just a few hundred kilometers, the Navtex signal is often received and decoded on much greater distance. During months of September, it is often copied as far as Sydney, Australia. Distance: 11,928 Km.
The best chance to copy NMC signal is during the hours of common darkness. The 12:00-12:30 UTC is the best time slot (around Californian sunrise), however partial decodes were possible just after local sunset at 08:00-08:30 UTC time slot.
Navtex messages form NMC received by VK2DX during September 2010. and 2011.
Receivers: ICOM IC-7200, Perseus, GenesisRadio G500. Antenna: 13m vertical + 8m loading wire, tuned with a 0.8 mH inductor. Decoding software: Yand.
73, Nick VK2DX