iPhone/iPad/iPod app to decode GMDSS transmissions
This weekend, I’ve noticed a station transmitting periodically on 6914 kHz. It will come on the air for a few minutes, then go off. All transmissions appear to be AM, with a variety of modes, such as CW (so MCW in this case), RTTY, and even some voice.
Last night I heard transmissions until the last one ended at 0136 UTC, when they stopped until 0745 UTC this morning. None were noted on the SDR recording during that time period.
When the transmissions restarted at 0745 UTC, they were extremely weak.
Here is an RTTY transmission (again, sent in AM mode) using 1000 Hz shift, 45 baud, with a center frequency of 1700 Hz, received at 2345 UTC 1 June 2013:
AGA5D2 DE A39P. FROM XXX DEFPAT ECHO X2 RTB XXXAFTER ACTION K
ART KKDUQLGLZXPQORU TUYI YUUOI PIOIU OUIYY WETYU IYOUI QRWET YTUII IUOPQ WYTUR TIOOQ PPOUY YYIER WEITY URYYU WQPOP TWLA IPQUQ QITWI PUPUQ IYUYR EWPQU TUIOW O
JAL4-6756 38677 192864 BT
A39P DE A5D2. ROGER OUT
The signal was not the best, so there are some errors in the decoded text. Here is an Audio recording of the transmission.
Here is a CW transmission at 1358 UTC on 2 June 2013:
And the decoded text, thanks to Token for providing it:
AHDR DE A50S COME IN K
A50S DE AHDR RGR GO AHEAD K
AHDR DE A50S CONTINUING ON SECPAT ROUTE. ALL CONDITIONS NORMAL K
A50S DE AHDR RGR COPY ALL K
Here is a voice transmission at 1431 UTC on 2 June 2013:
Token has reported this station on both 6914 and 23146.5 kHz back in December 2012.