Most authorities who monitor North Korea will tell you that they are a closed society with very little information about them getting out to the rest of the world. Consequently, we do not have a lot of opportunities to monitor any HF communications from the communist north.
In recent years, digital monitors have identified ARQ/FEC burst signals that are associated with the North Korean HF Diplomatic Network. Known as DPRK-ARQ and DPRK-FEC, this is a two-tone system with a 600 Hz shift.
You can see a sonagram of this signal at
http://sferix.sg1010.myweb.hinet.net/hfasia/files/DPRK_600Hz-600Bd.html.
You can hear an audio sample at http://www.iarums-r1.org/iarums/sound/10133dprk.wav
Past frequencies used by this network (freq in kHz): 6747.0 6748.5 8151.5 8737.5 9179.5 10258.5 10718.5 11438.5 12108.5 12202.5 12204.0 12205.0 12220.5* 12373.5 12534.5 12847.0 13248.5* 13378.5 13447.0 13457.0 13533.5 14018.5 14038.5 14247.0 14318.5 14327.0 14373.5 14442.5 14746.5 14778.5 14878.0 15017.0 15857.0 15858.0 15888.5 15999.5 16006.5 16058.5 16088.5 16118.5 16119.5 16128.0 16128.5 16131.5 16136.5 16211.5 16216.0 16218.5 16235.5 16238.5 16246.5 16314.5 16318.5 16348.5 16418.5 16448.5 16497.0 16858.0 18523.5 19241.5
* indicates a 1200 baud/1.2 kHz shift.
Some of the frequencies above may be transmitting from KRE embassies and not Pyongyang. For years KRE diplo comms were monitored in the 20 meter ham bands. I did a quick check of the IARUMS-1 October bulletin and it only shows the Voice of Korea intruding on the 80/40 meter ham bands and no diplo comms.
From the IARUMS-1 October 2010 bulletin:
Voice of Korea 3560.0 kHz at 1932 utc and 7200.0 kHz from 1100-1300 utc.
The latest report of KRE diplo activity comes from our friend down under Eddy Waters. He reported this morning monitoring MFA Pyongyang on 14778.5 and 18523.5 kHz around 0100 utc using DPRK-ARQ.
For the spook crowd there is an interesting article on http://www.abiweb.jp/ransu/ransu-e3.htm about "numbers stations" transmitting from the Korean Peninsula. If you follow this sort of traffic keep an ear out for Enigma designators V15, M40 and M82.
The M82 numbers stations are believed to be transmitted from the "BML" North Korean Army.
Sample format “vvv jvg jvg jvg de bml bml qsa qtc 587” R2 Or “abv qtc nr xxx xx xx xxxx xxxx xxx xxx =“ Known to send “r” as separator each 10 gps.
I do not have any recent reports on M82 traffic and the last frequency I saw reported was 8050.0 kHz.
Finally, Token in the Mohave on the spooks list posted the following yesterday:
"South Korean V24 and M94 traffic has had a very slight change in habits recently.
"The average message length has increased in the last week, not beyond the maximum that has been seen in the past but still longer on average.
"V24 has added a couple of new time slots and rearranged a couple of the old ones. For example in the last week or so there have been more 1630 slots than normal, but this could just be caused by errors in early slots. I can not prove but do believe that the 1630 slot is sometimes used to "catch up" or to correct for earlier errors in addition to hosting its regularly scheduled traffic.
"Other than this I have seen no changes to Korean or Chinese numbers traffic."
In response to a recent V24 report Token wrote this:
"A badly out of date web page that describes the station is found here http://token_radio.home.mchsi.com/numbers_station_v24.htm Sorry, I really need to update that page but have not had time.
"Since you heard the end you may have heard the Windows shutdown sound after the audio stopped. That does not always happen, but you can normally catch it (the shutdown sound) a couple times a month after the last V24 transmission of the day.
"V24 appears to use four frequencies at this time, 5715, 6215, 6330, and 6730 kHz. The schedule uses specific time/freq/day slots two days in a row. The one you heard today happens to be the first of that specific 2 day cycle, so if you listen tomorrow at 1530 you will hear a repeat of the same transmission. Other M24 transmissions that probably will happen tomorrow are 6730 kHz at 1200z, 6730 kHz at 1530z, and 6330 kHz at 1600z.
"There is an MCW (Morse code) sister station to V24, called M94. It appears at this time to use 5715 and 6330 kHz. Tomorrow there should be an M94 TX at 1400 on 5715 kHz."
As always reports, updates and additions are always appreciated. Email address in the masthead. Jefe.