Hi Jay and all LF EbNauters,
Many thanks for your reports and suggestions.
And many thanks Jay for your efforts. Yes, indeed: so I'll try tonite with a half of symbol duration, pratically the same parameters used in my transmissions on 14/15 Nov. 2018:
QRG: 137545 Hz
Duration: 28 min.
every 30 minutes, 1st transmission on 2100 UTC, last on 0700 UTC.
Reports are welcome as usual...
All the best
73 de Riccardo IW4DXW
Alex, Riccardo & EbNaut-eers
Unfortunately no copy of either station last night. Alex ... understand your TX frequency may have been moving around.
I wonder if a 1 hour transmission is too long for 137 kHz? Recalling spectrograms of QRSS going back many years seems to indicate a QSB pattern of approximately 15 - 30 minutes. Both receptions of IZ7SLZ and IW4DXW (a while back) were 'one and done' with no hint of the signal in adjacent time slots ... using 30 minute transmission times. Even DK7FC's normally big signal shows big QSB swings from one half hour period to the next. Can't help but wonder if 20 or 30 minute transmission periods make better use of the QSB characteristics on 136 kHz.