The Bulgarian diplomatic service is active on HF every day from Monday to Friday, working each station once a day on a fixed schedule.
The stations communicate using RFSM, a commercial off-the-shelf system formerly developed and sold by IDE Group. Its waveform is a derivative of MIL-STD-188-110.
The daily schedule is listed below. All times are Eastern European Time (UTC+2 from November to March, UTC+3 from April to October). All frequencies are on the upper sideband. The targets respond on frequencies different from Sofia, noted here as QSX.
|11:30||11011||Permanent Mission Geneva||11032|