The addition of PI4 to the U3 TX by Hans Summers suite of modes has lead to my testing it on 28MHz.
PI4 is not really a suitable mode for QRP but some users asked for it and Hans is always up for a challenge. Where those that asked for it are I don't know, but myself and EA2KV are using it on 28.303MHz time shared on the same frequency.
I have now been running the mode for over a month and there has been one solicited report from Greece. I always disregard solicited reports on established modes from any results but this is different the frequency has to be publicised.
I have also been running other tests concurrently awaiting unsolicited reports. These are possible because the signals are in a window where hundreds of highly skilled expensively equipped Hams are monitoring worldwide. WSPR remains the mode for propagation tests. It knocked QRSS off its perch when it was introduced. I have been running a comparison test on 28MHz for over 5 years and the report numbers are in excess of 100,000 WSPR to 1 QRSS.
For the test to be fair I TX each mode from the same transmitter and for the same period of time. WSPR carries Callsign, Locator and Power in 2 minutes, DFCW5 takes slightly over 2 minutes to send my Callsign only.
I have recently added FSKCW7 to the list, in just under 2 minutes it manages just a 'G'. That's fine, many years ago I grabbed a 'G' as my international identifier on QRSS, to keep it legal I also ident with the full Callsign. That has been running for over a month with the PI4 with no reports despite the fact I often see it on Grabbers.
Now I have just gone and publicised it so reports no longer count
Above. My little signal holding its own among signals into VE, some running 10 times more power. It took nearly 2 minutes to convey a not very readable 'G', in the same 10 minute time frame full WSPR decodes were made in the USA.
2014-12-07 14:48 G3ZJO 28.126190 -26 0 IO92ng +20 0.100 KB9AMG EN52tx
In order for QRSS to perform a useful service in the digital age it needs to be several times slower and the Grabbers need to have matching FFT times. The message time then gets to be so long that as a communication mode it is boring. However with an MEPT and Grabber set up it is ideal, after the first frame you can view and admire your own signal when ever you like.