Interferer to 10m WSPR

David G0LRD is seeing the same interferer that I am. Looks like it is coming in from some distance perhaps by Es.

Hi Roger,
The interferer in the 10m WSPR segment came back again this evening. It's rather odd. It is a very stable carrier modulated at about 0.0875Hz (7 tones every 80 seconds). It exhibits signs of long-distance propagation (fading, no doppler). The frequency of the pulsed carrier is precisely 28.126031 Hz.

It is rather annoying - I hope it doesn't persist.

David G0LRD

Doppler on 6m with G4IKZ (18km)

There must be more local flying activity at Cambridge Airport on Sundays (private flying?). On my 6m 1624z transmission there was 3Hz Doppler noticeable at G4IKZ - quite a bit when usually I get none at all. For a WSPR signal to be heard, the direct signal has usually to be much stronger than the Doppler shifted signal otherwise WSPR will not usually decode properly. Usually aircraft directions in flight have to be such that no Doppler is apparent for aircraft refection to work as a "path enhancer". I have noticed this with G3WKW in Hampshire on 144MHz WSPR over what is quite a long path. Get just the right flight direction and decodes occur. Otherwise, strong signals and no decodes. Sometimes G3WKW has been there for hours before he decodes on 144MHz.

G0LRD (25km) is just coming in on 6m at 1638z  at a strong -8 dB S/N with -4Hz Doppler, so his signal is arriving off an aircraft currently.