|Emission mode||USB; RFSM8000|
|Known counterpart stations|
MFA Sofia maintains a small HF network. Only a fraction of Bulgarian embassies is present on it. The communications are two-way, and use the off-the-shelf software modem RFSM8000, emitted in USB mode. The MFA and embassy sides almost always use different frequencies, usually less than 100 kHz apart.
The network is operational daily from Monday to Friday, and follows a fixed schedule according to Bulgarian local time. Known schedules are listed below. MFA Sofia, whose frequency is given in the Frequency column, always initiates the contacts, and additionally broadcasts a 1800 Hz tone shortly before the scheduled start time.