| |
Propagation |
|
JT6M is not limited to Meteor Scatter mode of propagation. It can be used very effectively
with other propagation modes - Tropo, Tropo Scatter, Es and TEP. F2 is probably viable prop mode too but at this stage of the current solar
cycle, I doubt if anyone has experienced this mode since it was introduced in early 2003. Aurora, of course, would be impossible ! |
- MS - Meteor Scatter.
This is the mode that JT6M is optimised for. Pings and short bursts can reveal part or all of the
transmitted message. It is possible to build up the message from pings, piecing together the calls/reports etc. Long bursts on 6M are
quite frequent.
Most JT6M MS operation relies on random meteors. Although random, these occur surprisingly very frequently and
an apparently "dead band" can become quite busy around 50.230MHz, particularly at the weekend. Of course, during major meteor showers,
there is more activity and many qso's can take place, with most completed very quickly.
|
- Tropo and Scatter modes.
Tropo mode JT6M qso's are very common for stations that are close to each other, e.g. <500km.
In certain cases though, decoding of signals can become a problem due to "multipath" propagation causing the same signal to arrive at
your antenna slightly out of phase (delayed). In these cases it may require you to beam away from the direct (or offset) path and rely
on scatter instead. It will depend of course on the strength of signal.
Ionoscatter mode can produced constant signals (similar to weak Es) and thus result
in the quick completion of a qso.
Scatter modes also work well particularly when the distance between 2 stations is short; both stations
deciding on a point to "aim" their antennas at. This can use either MS backscatter of Tropo backscatter, or a mixture of both.
|
- ES - Sporadic E
ES or sporadic E propagation can provide the JT6M operator with spectacularly long distance qso's.
During the summer Es season, take a listen around 50.230MHz. You can often hear stations from over 2000km away and the signals although
not necessarily strong, are constant and a qso can be completed quickly.
Even during random MS qso's, weak Es can occur, with signals present each way on every over, for a number
of overs, again allowing quick completion of qso. Multi-hop Es across the Atlantic to NA and Carribean are also possible. The next time there
is an opening to NA, try JT6M, you may well complete a true long distance qso. More stations are becoming active in this mode, even from West
and South Africa (TEP prop).
|
- F2
Look forward to reporting on this during the next solar cycle peak..............
|
|
