22 Apr 2011


Just a couple of outings on 10m WSPR this week, but some excellent reports from 5 continents using 5W and the small halo antenna. Interesting to see what must be Doppler shift drift on both the Reunion Is and Australian reports, presumably because of moving F-layer over the equator?


Anonymous said...

OK Roger, Condx on 10m seem to be improving; I was heard at A45SWL with 5W RF into a G5RV jr on wspr as well this morning;

2011-04-24 08:40 PA2RF 28.126160 -24 JO22gb 5 A45SWL

We'll see what 2011 will offer.
All the best, 73 Ron

John Desmond, EI7GL said...

With regard to the drift....The FR station is French Renunion in the Indian Ocean rather than South America.

Wonder if it had anything to do with their sunsets? The F2 layer gets lower and tilted as sunset approaches. Is it this movement in the F2 layer causing the drift?

You would probably have to check and see if there was any drift on these stations well before their sunset.

Roger G3XBM said...

Yes, you are right that there was no drift on the CX station, just on the VK and FR paths over equator in the Indian Ocean direction.

Anonymous said...

The doppler shift can also be caused by the signals reflecting of an aircraft.. I have seen this a lot on 10m, with similar shifts (tens of Hz). I have also seen double-traces of the same station, one caused by the normal reflections, and one by the doppler-shifted aircraft signal. I live near Paris, so there are lots of aircraft near here :-) Hugh G6AIG

Roger G3XBM said...


Yes, I have seen aircraft Doppler on 10m and 6m signals too, but usually only on semi-local up to 200km or so signals.

73s Roger

John Desmond, EI7GL said...

Looking on the net, VKJED's site suggests that a speed of roughly 120 kph would be needed for a 3hz shift...not very fast at all