However, there is one big obstacle to using the MSHV multi-response sequence on a DX vacation.
That is, if you use a “non-standard callsign,” that is, a callsign that has a “/ (slash)” (indicating that it is a mobile station) followed by any letter other than “P” or “R,” the multi-response function will not work.
In fact, if you set the callsign “JK1FNN/JD1” to MSHV, even with one slot operation, it will only respond to one station, and will not respond to multiple stations (two stations) at the same time. There is no advantage to using MSHV in this case. (I actually created and recorded a dozen different FT8 modulated signals, mixed them, played them back, and checked by decoding them with MSHV.)
This seems to be due to the specification of the original FT8 mode itself, which states that “callsigns longer than 77 bits are hash coded.” This is the same as the situation where the autosequence goes endless when both “JK1FNN/1” and “JQ1YLK/2” start a QSO.
WSJT-X User’s Guide 7.5 “Non-standard callsigns” says the following (abbreviated translation below): –Angle brackets mean that the enclosed callsign is not transmitted in full, but as a hash code that requires fewer bits (77 bits or less). The receiving station will display the non-standard callsign in full if it has a full callsign received recently. Otherwise, it will display <….>. These restrictions are automatically imposed by the algorithm that generates the minimal QSO default message. Except for the special cases of “/P” or “/R” used in VHF contests, WSJT-X 2.6 does not support two non-standard callsigns communicating with each other. —
To solve this, if you somehow get a callsign without slashes at your destination (JD1***, not JK1FNN/JD1), you can use the MSHV multi-response function… but should you really take on the now very difficult challenge of “getting the JD1 callsign” to do so? It’s something to think about.
In this way, the MSHV is unnoticeable in normal use, but when called upon it switches to multi-response with one slot, increasing its processing power. This versatility makes it the perfect tool for “indecisive DX vacations.” If you find yourself being called upon more often, you can self-spot and QSY from 074 to 080 to use two slots.
However, since the MSHV does not have a Hound mode, it might not be suitable for everyday use from home.
(2023.12.23)
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