sea paths on 6 cm ??

[g6urm]

hi all - this for discussion ( and something i'd really like to try some time when kit sorted .lol )

I was just looking at dx paths on google earth - there is a useful path profile plot feature on there - and noted that an all sea path from start point in Devon to either the IOW - or Portland is about 80 - 100+miles - reading up on sea paths at 5 -6 ghz - it seems there is a lot of interest in this in military and naval areas round the world for all sorts of applications

to do this of course one would need the right conditions - but apparently ducts form above the sea on a fairly regular basis on warm sunny days with a mean height of some 30 m - not an impossible condition for either path mentioned ( of course getting a warm sunny day and people willing to try is another question .lol )

but what do you think ?? - has anyone gotten across any sea paths for instance on 6 cm ?? or even tried for that matter ?? saw some work by french amateurs on this with good results - and the dutch lads seem to have embraced this band too

any way something to ponder


reference : https://www.radioeng.cz/fulltexts/2014/ ... 4_0830.pdf

[g0mjw]

Yes

[g6urm]

thanks - um would you care to elucidate ?? - on your successes please

[g0mjw]

thanks - um would you care to elucidate ?? - on your successes please

There are lots of examples of sea paths reported in the literature (e.g. Dubus) working up to 10GHz. Quite a bit of analysis too. The paths you describe would need to be relatively calm to work at 5.6GHz but VHF/UHF paths like Cornwall to Spain and onwards to EA8 are well known, as is Hawaii to California. The UK is not a good place to be for this. it is rarely warm or calm enough for an evaporation duct over the sea to extend beyond 5m in height this far North. You can expect 10-15m in the Mediterranean and often much more over warm seas like the Caribbean and Gulf. So, (mostly) forget it in cold wet and windy places like here. However, in the summer evenings you can get coastal advection (wind) of warm air out over the sea where it mixes with the moist sea air to extend the height of the duct. That's when you get the big lifts. In the 1980s and 1990s there were regular paths along across or along the North Sea. These are much less common now but if you have a mate in Northern Spain it might be worth trying.

http://www.mike-willis.com/Tutorial/refraction.htm

Mike

[g6urm]

interesting - i was thinking more of GU / GJ ( anyone over there into 5.6 ghz atv ?? ) - but first things first eh .lol - there are several places around here with good take offs sea wise

and oh yes i remember the megga lifts of the 80's and 90's well - was up on Dartmoor living then - 1460 ft asl - worked all over Europe on 2 m FM !! - let alone ssb - and could work into portland virtually anytime ............................ happy days