FAI & DB0FAI
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The beacon DB0FAI ? DB0FAI is off air since August 27th 2014 !
FAI ( Field Aligned Irregularities ) is like Aurora, a scatter propagation at irregularities in the electron density spreading along the Earth's magnetic field lines. The special feature of both phenomena is that the antenna must be turned not to the partner, but toward the so called backscattering area. At the scatter, which is located at a height of approx. 110km, the signal is reflected back to the earth. In contrast to Aurora ( high-energy particles coming from the sun ), the release mechanism for FAI is still not known. Own observations and the analysis of various logs allow to assume a relationship with Es-propagation.
Contacts during the last years in Europe have shown that the best chances exist from May to August. A connection with the time of day has not be proven so far.
It was shown, as also with Aurora, that the occurence of this effect is dependent on the latitude of the location. Aurora which occurs e.g. in Northern Europe very frequently, is however in South Europe a rarity. With FAI it's exactly the other way. Most contacts in Europe run in the summer between Spain as well as Southern France with Slovenia, Hungaria and Italy.
In Germany FAI occurs more seldomly. Nevertheless, from South-DL some contacts were already made. Tests of DL4MEA and DL5MCG with SV1DH in June/July 1987 have been taken very successful. We had contact with Costas at 10 of 15 days ( -> 66% with QRB = 1571km) on 2m ! Here it is to be considered that the antennas were aligned already from the beginning to the most favorable Scatter, which was in for instance over Budapest. The line of these Scatterpoints can be calculated for any partners, with a great deal of mathematical effort.
The signal is usuallly very weak. For this reason as good equipment as possible is recommended. The lower limit should be a longyagi and a transmitter with at least 100 Watts. Although during the tests Costas (SV1DH) could be worked even with a single 8el Yagi and 50 Watts.
To support this fascinating propagation mode and to be able to detect scatter areas over Central- and WesternEurope better, we ( DL4MEA& DL5MCG ) have operated a high power beacon with the call DB0FAI since May 1990. Here are the most important details:
Once again, please note that it makes no sense to turn the antenna (all the same whether Aurora or FAI) directly to the partner. Thus we have received e.g. a Aurora receiption report from Dresden, hearing the beacon with antenna-direction 290 degrees (NNW). The calculated scatter area was over Great Britain closed to Sheffield!
DB0FAI is off air since August 27th 2014 !
After nearly 25 years of operation the beacon is now off air because of dismantling of the silo on which the antenna was mounted.
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