Enigma ID M42 (catch-all MFA Moscow designator)

Spectrum image serdolik-spectrogram.png

Name Serdolik
Status Active
Voice N/A
Emission mode USB; MFSK-34, 40 Bd; OFDM-34, DBPSK, 40 Bd; OFDM-34, DQPSK, 40 Bd
Location Worldwide
Activity pages

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Known counterpart stations

Serdolik[1] is a currently semi-retired proprietary full duplex ARQ system used by the Ministry of Foreign Affairs of Russia. From late 1990s until early 2010s, it served as the most common two-way HF mode of that organization. At present, while still being used, it is seen only on a handful of links; most of them have been upgraded to the newer "Perelivt" system.

Its main waveform is 34-tone MFSK at 40 Bd, which offers a gross data rate of 200 bit/s. The modem also contains a 34-carrier OFDM waveform, modulated at 40 Bd using either DBPSK or DQPSK, which offers higher speeds of 1200 bit/s and 2400 bit/s respectively; however, it is rarely used nowadays.


  1. Serdolik HF communication system - JSC Sozvezdie [accessed May 31st, 2018]
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