ARLA/CLUSTER: "Lightning Scatter" um outro modo de propagação tentado pela 1.ª vez em 50 MHz na África do Sul

[João Costa > CT1FBF]

Lightning Scatter* on 50 MHz

The South African Radio League (SARL) say Lightning Scatter is another
VHF propagation mode, but that two-way contacts have never been tried
in South Africa.

Many years ago, a FM broadcasting station in Durban on the 88 to 108
MHz FM band was heard in East London by ZS2FM during a lightning
storm. Every time a lightning flash occurred, from a distant
thunderstorm in the direction of Durban, the FM signal would pop out
of the noise at full limiting and last for about ten seconds before it
faded out.

Recently radio bursts from lightning on 144,300 MHz SSB, emanating
from ZS6CBQ at Krugersdorp, were picked up by ZS4A in Bethlehem, even
though they were of very short duration, the voice of ZS6CBQ was
recognizable. This suggests that brief two-way contacts on 50 MHz
should be possible on SSB, FM or Digital during a thunderstorm.

The late afternoon thunderstorms, normally experienced in the summer
months around Johannesburg, could be a wonderful testing ground for a
lightning project. Of course, only distant stations surrounding
Johannesburg area would be able to participate, as all antennas will
be grounded in the area where the storm is raging.

If you are in Pretoria then beam at the storm in Johannesburg area and
give a brief call during a lightning flash, while only listening
during the next flash. If you can't see the lightning flash then call
when you hear the static burst on receive. In theory, it should be
possible to make contacts as far south as Bloemfontein.

Who will be the first to a make a contact via Lighting Scatter on 50 MHz?

Fonte: The South African Radio League

Lightning Scatter* - O "Lightning Scatter", que pode ser traduzido em
português por "Dispersão pelo Relâmpago" proporciona oportunidades de
DX principalmente nas bandas de VHF e UHF, e é causada pela ionização
da atmosfera criada pelo raio durante uma tempestade eléctrica.
O efeito da dispersão do raio é semelhante à conhecida "Meteor
scatter" em que os contatos são breves e imprevisíveis. Em geral, no
entanto, a tempestade eléctrica deve estar a meio caminho entre as
duas estações para que as comunicações ocorram.
As distâncias alcançadas usando a Dispersão pelo Relâmpago são
geralmente no máximo de cerca de 1100 km (700 milhas).