Thursday, October 31, 2019

Comparison of the FT8 and WSPR modes on 28 MHz - 31st Oct 2019

For the months of May & June 2019, I left the radio listening to FT8 signals on 28 MHz and fed the reception reports up to the PSK Reporter website. With the Summer Sporadic-E season in full swing, it kind of got very repetitive in terms of what was being heard with each days list of stations looking pretty much the same as the previous days.

For the second half of the Summer, I spent a lot more time listening to the WSPR frequency on 28 MHz and uploaded those spots instead. Once we got to September however, the number of reports really began to diminish.

FT8 V WSPR... As an experiment, I tried out both modes today on 28 MHz. My objective was to listen at a time when the band was open and see how the activity on each mode compared.

Session 1... 30 mins of FT8. There seemed to be plenty of signals around 12:00 UTC and this is what I heard on FT8....


Session 2... 30 mins of WSPR. I went to the WSPR frequency and I heard nothing. I could see the odd bit of a signal on the waterfall but no decodes.

Session 3... 30 mins of FT8. I switched back to the FT8 frequency for 30 mins and heard the following...


Obviously conditions had declined a bit from session 1 but I was still hearing signals.

Session 4... 30 mins of WSPR. I switched to the WSPR frequency for 30 mins and heard nothing.

I checked the WSPRnet website and it said that there were 84 stations active worldwide on 10-metres during this period. If I take out the receive only stations then there were just 21 stations in all of Europe transmitting on WSPR on 28 MHz.

Conclusion... Even though WPSR is a fascinating mode, it does require enough users to be operating on the band to make it useful. I'm of the opinion that outside of the summer Sporadic-E season, that critical mass doesn't exist for WSPR on 28 MHz.

Maybe things will be different as we leave the sunspot minimum but it seems to me as if that on 28 MHz at least, FT8 is the only mode that has a critical mass of users.

Addendum : Later in the evening, I heard Mauritania, Argentina and the Falkland Islands on 28 MHz FT8.

4 comments:

PE4BAS, Bas said...

Have the same exprience here. WSPR on 10? Well....I think it is over. At least for propagation research. 73, Bas

Photon said...

Yes, that is also my experience. The situation is even worse at 12m.

In general, the real-time results, faster than WSPR, that FT8 affords are still at a disadvantage, in that we are looking at something like a 10dB or so better sensitivity for WSPR for those who have the lowest noise floors. So I disagree that WSPR is finished for research, although QRM from the other modes is now a big issue.

One thing a bloke at the RSGB was investigating, and we had a discussion about, was the need for a propagation-probing mode that is fast AND sensitive. That would reveal even more transient phenomena - much shorter effects than WSPR can show up.


stu said...

propagation probe mode...now that is something i would like to see Photon

John, EI7GL said...

The problem with any new beacon mode will be how people will actually use it. Will there be a critical mass?

At least with FT8, there are plenty of people trying to contact each other so at least there are signals on the higher bands to decode.

Other modes include JT65 and PI4 but only a few beacons seem to use those modes.