|Emission mode||USB; MFSK-17, 10 Bd|
|Known counterpart stations||E07, G07, S07, V07, M12, XP, XPA2, XPH|
XPA is a digital flavor of the Russian 7 operator. It utilizes a custom 17-tone MFSK mode.
XPA operates in regular schedules of three transmissions, spaced 20 minutes apart. The frequencies of the subsequent repeats decrease for schedules at 00:00-12:00, and increase for schedules at 12:00-24:00, in most cases by about 1-2 MHz.
XPA messages consist of 5-digit groups. There is a 3-digit schedule ID associated with each message. The purpose of the first and third groups are unknown, but the second group is the group count minus three. The first digit of the first group is always zero.