Showing posts with label stability. Show all posts
Showing posts with label stability. Show all posts

2 Feb 2014

2m WSPR - Sunday

Already I see G3WKW's 20W of 2m WSPR (134km) is appearing on my screen at 0902z at -22dB S/N. As there are 4 UK stations active on 2m WSPR I wonder if I shall see, or be seen, by others too?

Stability is the main issue with the FT817's warm-up drift. The trick is to check GB3VHF's dial frequency as this GPS locked. Use the same offset on WSPR and one should be spot on. A 0.5ppm TCXO would help too, but not worth the outlay. I  have a similar issue (not as great) at 6m where I always set the rig 40-60Hz low after allowing it to stabilise. This seems to get 6m WSPR pretty close.

At 0956z  I see my 2W WSPR to the halo has been spotted by G8XWR in IO91oc at 150km. That is encouraging as it is the far side of Guilford and Farnham and further away than Bob. I notice strong Doppler, so probably aircraft reflection.

Lae in the afternoon G3WKW swapped to a lower loss feeder and his signal increased and he began to copy my QRP signal.

In all it was a successful day on 2m WSPR but my drift issue does need to be improved. The DX spots are due to aircraft reflection (when Doppler suits - i.e. little) and the SW package mentioned below helps to predict best opportunities.

144MHz WSPR spots sent and received today (2W and halo)