11 July 2018

110A & S4539 data transfers

06690.0/usb 0627z: two unid stations in simplex exchanging KG-84 encrypted msgs using 188-110A  and S4539 waveforms. The exchanges were repeated several times during the morning w/out ALE handshake neither voice-comms before the init of transfers.

Fig. 1
Fig. 2
Probably a modems set-up like the one in Figure 3 was used

Fig. 3