Known as DPRK-ARQ and DPRK-FEC, DPRK-ARQ 600bd/600 is a proprietary two-tone FSK system with a 600 Hz shift. This system is used by the Democratic People Republic of Korea (so the abbreviation DPRK) with 600 Baud and, as said, 600 Hz shift for their HF diplomatic traffic in ARQ mode on LSB.
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| DPRK-ARQ 600/600 sonagram and spectum |
The block length is 217 ms, the pause 323 ms so that the total packet has a length of 540 ms. Each bit has a length of 1.67 ms so that one packet has 130 bit.
Sometimes they use DPRK-ARQ 1200 with 1200 Baud and 1200 Hz shift (DPRK-ARQ 1200/1200):
Sometimes they use DPRK-ARQ 1200 with 1200 Baud and 1200 Hz shift (DPRK-ARQ 1200/1200):
I spotted that today! UK.
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