Some very interesting traces on 4m WSPR.
With G0MJI especially I can see the Doppler effect very clearly. Presumably this is due to aircraft reflection. As well as the main trace, often strong and with no drift (WSPR reports even slight drift, say 1hz), there are other traces on the waterfall.
Generally the Doppler is tilted down at about 30 degrees, or up to 45 degrees sometimes. Thus, reading the waterfall scale, the shift is about 20 to 30hz, depending on the severity of the effect. They always slope down left to right which suggests to me that the aircraft (?) are only moving away from me (or the universe is expanding more than I thought). No doubt some simpler explanation can be found for this as G0MJIs traces of my signal look similar.
Sometimes the Doppler line starts at a higher frequency than the main signal, and crosses its path in the form of an X.
At other times, only the Doppler lines appear, with no or very weak direct signal (which does suggest aircraft reflection).
I have seen similar results from signals coming from the South, but not so much on traces seen from GM, GW or PA.
As the WSPR waterfall is only 200hz wide, it is easy to see the effects. You can also see who has a stable rig/transverter, and thankfully G0MJI is perfectly stable.
If you are going on to 4m WSPR, it is a good idea to let people know via the WSPRnet chat page. Other bands have a map entry, but not 70MHz, yet. The frequency in general use is now 70.091 (dial).