Grand Cayman & other Caribbean Paths

When David, ZF1DC, emailed me about this series of pages I suspected he would have some great information to add. I wasn't dissapointed. An active operator with a very good station in Grand Cayman, David has found some interesting paths both to Europe and the Caribbean area on backscatter from EK99. Another path David has found may even lead to Long Path QSOs with the Middle East & India, or even Europe. Operators in the Caribbean, North America, Asia & Europe should pay close attention to David's discovery.

The first path David mentions is the skew path to Europe from Grand Cayman. For David the beam heading is around 100 degrees, with a scatter point somewhere in the central Atlantic. This propagation is likely the result of multipath scattering (& reflection) of the signal along the geomagnetic field lines, and most often occurs near the equinoxes with stations suitably situated in the TEP zone in Europe & the Mediteranean. At ZF1DC's geomagnetic latitude, this path may produce more often than it does for more northern stations located near, but not situated in, the TEP zone. However, Florida stations, and particularly those further south in the state, are sometimes able to take advantage of this path without an additional mode of propagation to link into the scatter area, and during the winter of solar peak years stations in the far western United States have even managed scatter path QSOs with Europeans in this fashion.

The second and somewhat less familiar path David describes occurs at a beam heading of around 200 degrees from Grand Cayman, more or less in the proximity of the Galapagos Islands. He has "worked into KH6, W5, W6, W4, KP4, FJ5, and most central american and caribbean countries that are active" along this path, and has heard Canary Island stations along it as well. However, David explains that this "is a fall/spring path, and during winter F2 season has not produced much." Interestingly, this path falls almost exactly within an area where the magnetic field lines slightly compress as they begin curving northward at the base of the dip in the geomagnetic equator. It is possible the slight compression and curving of the field lines in this region create an environment more conducive to enhanced levels of ionization. Whatever the cause, around the equinoxes, it is apparent this area enjoys a more frequent & steady level of ionization, allowing for frequent backscatter QSOs between stations in or adjacent to the TEP zone. This path is occassionally evident even as far North as W 1,2 & 3 as evidenced by the appearance of the HC8GR beacon, though at Northern latitudes the path is seldom strong enough to support backscatter QSOs.

David has also found an as yet unknown long path, slightly further west than the backscatter path previously described. Though so far it has not produced any QSOs, it is likely just a matter of time and vigilance. He explains:

The really interesting path that I spent alot of time trying to figure out was beaming 210-220. On this path I heard video 48239,48244, 48250, 48.260, 49750. This would seem to be LP to the Middle East or EU. I think the path opened to both places on different nights. The video came in around 03-05Z and was strong for many consecutive nights in Mar/Apr 2002. See http://www.qsl.net/zf1dc/2002highlights.htm for the exact number of nights. On many of these nights I was also hearing the HC8 bcn very strong.

I emailed many stations in the ME but was unable to build any enthusiam for the stations to wake up a little early and check 6m for an hour in their early morning. I did run skeds with SV1DH on many nights but with no success. When we ran these skeds many stations in EU listened. Unfortunately the video was only in a few times during these skeds.

Now that I am aware of this possibility I will be prepared this year or in the future. Hopefully I can get some of the ME stations to watch this path also. I think there is a remote possibility of working into S. Asia also along this path or possibly a little further south. I have gotten good response from VU2ZAP and he will be watching this path in spring. I have suggested to the stations I emailed to pay particular attention to the HC8 bcn because I think this will be a useful indicator for them. Plus it is about the only strong bcn in the area.

If the propagation is strictly antipodal "direct" (that is, without a skew somewhere along the path) it is highly probably that the video is of Middle Eastern or Eastern European origin. In such event, aside from other obvious choices, the video could also possibly originate from Tadjikistan, Turkmenistan, and Armenia. The presence of even a slight skew on the path creates additional possibilities, including Asiatic Russia and Kirghistan. Todd Emslie's TV Frequency List for TV DXers reveals possible sources for the video received at ZF1DC, including Iran (48.239); Iran, Dubai or Syria (48.250); Iran (48.260); Turkmenistan, Kazakstan, Azerbaidjan or Tadjikistan (49.750) - presuming of course a propagation path with little or no skew. 48.244 does not appear on any list I examined, though it may be a sideband of Iran TV-2 (48.259.631) or another, undocumented source in the region. If a more major skew is involved, source prospects for the video change. In such event the 48.239 & 48.250 video could originate in Thailand (as do a number of 48.260 carriers), and 49.750 from any of a multiple of sources in mainland China.

It is also hard to ignore the fact the great circle path curves over and through Western Russia, the Ukraine, and finally over Belarus, Eastern Poland, and Denmark. Video documented along the path could perhaps even originate from this region, though propagation would likely be substantially weaker as geomagnetic latitude increased along the path. Wherever it ultimately emerges, stations over a wide area should check it frequently at the appropriate times- doing so will likely lead to some spectacular DX.

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