Monthly Archives: October 2008

AIS – Range

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I’ve come to expect AIS reception to be in the same practical range as VHF reception and have been more than happy to see ships up to about 36 miles away. When I recently picked up ships more than 200 miles away, surprise was not enough, and I had to resort to astonishment (to quote the Hitchiker’s Guide to the Galaxy)!

Not sure what happened: an atmospheric anomaly, reflecting the VHF signal back, or is there some form of repeater being used around the Sydney/Newcastle area?

AIS reception of ships in the Sydney Area, more than 200 miles away

Practical Range for HF Weatherfax Reception

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I spent a bit of time rigging a long-wire antenna at home today to see what sort of range is practical for HF Weatherfax reception:

  • The antenna is now about 20 metres long, made entirely from inexpensive hookup wire.
  • The antenna is L-shaped, with one leg oriented East-West and the other North-South.
  • I’ve also connected an earth wire to a copper stake just outside my window, significantly reducing background noise.

To my delight the little Degen DE-1103 receiver pulled in the Wellington MetService broadcast on two of the four frequencies! That’s 1,000 nautical miles! Local weatherfaxes from Charleville (WMC) are now clean and crisp.

HF Weatherfax received in Sydney from Wellington