From Dave G3YMC
Some more points of musing.
G0MRF asks what the signal to noise ratio is for CFH. Noise varies enormously
between different QTHs, however the signal I receive from CFH during the night
and around dawn is s9+10. or 14uV on my quite sensitive receiver (DCF39 is
45uV). To put this into perspective this is just a little below the signals I
get from John G4GVC and Dave G3YXM, and stronger than quite a few of the
regulars. It certainly prevents use of 137 and around while it is there!
It is now suggested that CFH is running 250kW, rather than the 25kW mentioned
earlier in the year. That will add another 10dB to any calculations! The
single hop propogation distance was also mentioned a few weeks ago as being
between 1724 and 1988km. CFH is 4593km from here, so it is likely to be 2 hop
with the reflection layer being a little higher than suggested in those mails,
and with a sea hop in the middle.
The distance to WA2XTF/6 is 5880km, which presumably can only be achieved with
3 hops, one of which may be over land, which will obviously increase the path
loss. Clearly there is hope for a QSO into VE1 land (if CFH is off!), but I
remain pessimistic even of W2 land.
Many thanks to Jon and the other guys at CFH. Calculation of CFH propogation
is invaluable in the quest for an eventual transatlantic amateur QSO, although
once the novelty of hearing it has worn off it becomes rather more QRM than DX!
If only we could get the same sort of rapport with the staff who man the Rugby
station on 73.4!
73s Dave G3YMC
dsergeant@iee.org
http://ourworld.compuserve.com/homepages/sergeantd
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