Friday, July 20, 2018

Russians Interferring with more than the US Elections!

11175 kHz Russian CIS 12 transmission heard on a South African Remote SDR.
For the last several days now major interference has been noted on the US military primary worldwide frequency for their HF-GCS net of 11175 kHz.

Further analysis of the signal show that it is a Russian Military CIS 12 digital transmission. According to (

"CIS-12 (Also known as MS5, FIRE, AT-3004D, or AT-3104D) is a 12-tone PSK Russian military multi-channel modem. It features scrambled voice/ data-communication at a maximum data rate of 4800 bps. Each subcarrier transmits at 120 Bd. There is 200 Hz of spacing between each subcarrier.
This waveform is transmitted by the AT-3004D and the newer AT-3104D military modems in use by the Russian Military. These modems were designed to have many different devices plugged into them to form the modem’s input – mo ften teleprinters unique to the different military services and civilian agencies that use them, and also, vocoders and speech encipherment systems, but all are transmitted in the same fashion.  A characteristic trait of this signal is the carrier signal located +3300 Hz on the right side of the signal."

11175 kHz Russian CIS 12 transmission monitored on a southern Greece remote SDR.

I am sure that DoD and the HFGCS op on the 11175 kHz console at Andrews are not a happy campers these days.