|Emission mode||USB; FSK-2, FSK-4, GFSK-2, GFSK-4|
|Known counterpart stations||E11, G11, S11, S11a, M03, F11, P03|
The designator F03 refers to the FSK modes. At least the following variants are known to exist:
|Variant||Tones||Baud||Shift [Hz]||Center [Hz]||Block size [bit]||Sample|
All F03 schedules are twice weekly, follow year-round UTC (no DST adjustments), and use up to three different frequencies depending on the month - one from November to February, another from May to August, and yet another for the remaining months. Each F03 transmission is followed by an identical repeat 5 minutes later.
F03 and P03 have been active since at least 2014, gradually replacing the older digital mode F11 over the next four years.