More 6914 Oddities 0647 UTC 30 Nov 2013

[ChrisSmolinski]

0647 On for about a minute with some distorted audio, it sounded a lot like an audio clip heard here, or close by, months or perhaps a year ago.
http://www.radiohobbyist.org/blog/mypics/6914_0647.mp3

0702 On again: http://www.radiohobbyist.org/blog/mypics/6914_0702.mp3

0732 http://www.radiohobbyist.org/blog/mypics/6914_0732.mp3

0747 http://www.radiohobbyist.org/blog/mypics/6914_0747.mp3

0817 http://www.radiohobbyist.org/blog/mypics/6914_0817.mp3

0847 http://www.radiohobbyist.org/blog/mypics/6914_0847.mp3

0901  http://www.radiohobbyist.org/blog/mypics/6914_0901.mp3

0931  http://www.radiohobbyist.org/blog/mypics/6914_0931.mp3

0946  http://www.radiohobbyist.org/blog/mypics/6914_0946.mp3

1002  http://www.radiohobbyist.org/blog/mypics/6914_1002.mp3

1017  http://www.radiohobbyist.org/blog/mypics/6914_1017.mp3

1032  http://www.radiohobbyist.org/blog/mypics/6914_1032.mp3

1047  http://www.radiohobbyist.org/blog/mypics/6914_1047.mp3

1116  http://www.radiohobbyist.org/blog/mypics/6914_1116.mp3

1132  http://www.radiohobbyist.org/blog/mypics/6914_1132.mp3

At 1146 it went into RTTY, but with AM modulation. 50 baud 1000 shift:
DG8I DE DDIN. FROM XXX DEFPAT ECHO X2 RTB XXXAFTER ACTION REPORT XXX 97874 101947 5768 67798 08987 97866 23567 86978 14235 65788 87901 26574 58991 00976 66834 23856 74667 21090 52809 80171 18528 07071 86764 32017 57892 93756 01276 96756 90008 67654 101947 5768 67798 08987 97866 23567 86978 14235 65788 87901 26574 58991 26745 10985 BT DDIN DE DG8I. ROGER OUT


More RTTY at 1202:
DZJH DE DD70. XXX DEFPAT NOVEMBER XW DEPARTURE XXX BTJIDD70 DE DZJH. ROGER XXX PROVIDE AFTTYL EION REPORT AND MISSION SUMMARY UPON MISSION COMPLETION


CW messages started around 1311z, too weak to decode well.

[Tom S]

This looks a lot like the suspected US military SIGINT intercept training traffic I used to copy all the time back in the mid to late 90's.  The frequencies in use back then were 10225 and 16303.6 running parallel.  There were all sorts of different types of message formats sent, some obviously fake plaintext, but lots of coded message group traffic.  Modes used were CW, Sitor-B (FEC), RTTY in various different speeds but always 170 Hz shift, and even ASCII mode.

According to my logs I first logged it in 1996 and last logged it in 2007.  I've also on occasion found other activity on other frequencies which may have been related to SIGINT operator training.

[ChrisSmolinski]

Thanks for the info, Tom.  What I found curious was the use of AM mode, even for the CW (MCW) and RTTY. The choice of 1000 Hz shift for the RTTY was also surprising.

[ChrisSmolinski]

Heard again around 2358 on 2 Dec 2013, and a few other transmissions such as at 0028z. Same audio as I heard months ago, a conversation between an OM and YL, with over-emphasized pronunciation. Tough copy due to a nearby UTE.

[OldSeaRock]

03:11 UTC 7 Dec 2013

Several odd digital transmissions, then nothing.  I'm not that familiar with digital and perhaps caught the end of something which began earlier.