Trying to operate WSPR while on holiday in Italy I discovered that the max size for callsign is 6 characters. So I can't use my guest prefix of I0/PA5FDX. Maybe this could be fixed in the next firmware update?
The WSPR protocol is strict about its callsign requirements and only allows 6 characters, and in a certain format. There is an "extended mode" which allows a longer callsign, which can include 3 prefix characters OR one single character suffix OR one double digit suffix. This mode can also send 6-character Maidenhead grid subsquare, not just the usual 4 characters gridsquare. However, it requires two WSPR transmissions to send all that information and the decoding station needs to receive both pieces. There are other disadvantages too.?
"Extended mode" is supported by the Ultimate3S QRSS/WSPR kit - but not by the QCX. In the QCX the primary function is as a CW transceiver. I added the WSPR beacon mode because it is cool and it is anyway just firmware. I did not try to replicate the full functionality of the Ultimate3S. I kept it a simple, basic WSPR implementation. That's why it doesn't do anything extra except just basic WSPR. If there is demand for it, I could add the extended WSPR mode in a future firmware version.?
My recommendation is just send as PA5FDX . I don't think it would upset anyone. The?I0 prefix is anyway redundant information since your locator will carry that information (you are in Italy, after all). WSPR is not human readable, it is a heavily encoded (but not encrypted) digital mode. One could easily argue that the?I0 information is supplied by the locator, I think. Not that any such question is ever likely to arise.?
tom van der meer
va3rr