VHF Range - What's Your Record?

[Amphitrite]

Once during dense fog in the approach to Gotheborg we heard Rostock Port loud and clear, which is a good 200nm away and with Copenhagen in between...

In autumn I repeatedly saw AIS reception from receivers in Norway of stations on the East Coast and in the Channel, more than 300nm away....

 

[ColinR]

Last summer on passage from NW Spain to Azores I spoke to a German yacht on the ARC going from Azores to S Portugal. They were 140 miles away. Reception was excellent on Ch16 but nothing heard on Ch72. Then we tried ch6 which worked fine. I was amazed.

 

[Roberto]

Would love to know how that's possible

Try searching "tropospheric ducting" for example


:smile:

 

[Roberto]

like this one for example

http://en.wikipedia.org/wiki/Tropospheric_propagation

 

[ColinR]

on same trip to Azores I set the navtex to all stations for a while and was getting the Great Lakes and Algeria. Not much use to me, I wanted Horta and only ever picked it up when I was in Horta harbour! How can that be?

Colin

 

[Slow_boat]

I used to get interference from Dutch fishermen on my police car vhf at Newport Pagnell.

 

[MM5AHO]

Tropospheric propogation (ducting of the signal in high barometric pressure) is only one a several mechanisms that can cause extended unusual distance VHF reception.

Others include signals being reflected off iosised areas of the E layer of the troposphere, reflections off meteor showers, reflections off aurora, and even reflections off the moon.

Distance records of over 4000 km have been aceheived at about 144 MHz, just a little lower than the marine VHF band, but moon bounce (as its called) can allow a contact to be made at over 12000km. Of course most of these rely on special high gain antennas.

My best reception from a normal marine band mast mounted whip antenna is Wales from Scotland ( Mull to Holyhead).

 

[Boz]

on same trip to Azores I set the navtex to all stations for a while and was getting the Great Lakes and Algeria. Not much use to me, I wanted Horta and only ever picked it up when I was in Horta harbour! How can that be?

Colin

MF (518 kHz or 490 kHz)... different propogation Criteria, I often hear and decode Halifax (Nova Scotia) at home here in Lincolnshire.
Regards
Russ