May has been an interesting month for Drift Net Beacons in the Pacific region. Some signals have reached 599 report at various times of the late night/early morning monitoring sessions.
Some call sign variants have also popped up, normally in this region I only hear 2X1 (two letters one number) but this month some surprises have been heard:
1.776 CW 2AFFG 0810z 529 22nd May 19.
1817 CW TTT 0854z 529 22nd May 19. Possible misfiring beacon, can be heard as TMT on occasions, irregular character spacing.
1922.5 CW FP919 1119z 549 24th May 19.
1978.5 CW FK221 1020z 569 22nd May 19.
1978.5 CW FQ85? 1024z 559 22nd May 19. (? indicates missed number)
2005 CW 7G 1935z 539 22nd May 19.
2005 CW 8F 1634z 559 24th May 19.
2122 CW DO63 1810z 519 02nd May 19.
2139 CW 4FRL 1933z 569 19th May 19.
2218 CW AN94 2030z 519 19th May 19.
2307 CW BMD1 1039z 519 19th May 19.
2317 CW BMP9 1042z 519 19th May 19.
A line of call sign series has also emerged, often only a few Kilohertz apart:
1831 CW OB2 0746z 569 24th May 19
1842 CW OB3 0942z 519 21st May 19.
1853 CW OB4 1320z 539 22nd May 19.
1863 CW OB5 0859z 559 02nd May 19.
1811 CW OA0 0831z 519 21 May 19.
1801 CW OA9 0830z 529 21 May 19.
1789 CW OA8 1450z 519 02 May 19.
1779 CW OA7 1603z 559 20 May 19.
1748 CW OA4 1117z 529 20 May 19.
1717 CW OA1 1421z 559 24 May 19.
Only need OA2, OA3, OA5 and OA6 to complete the above "OA" series.
The above observations make logging and chasing DNB's all that much more interesting, especially call sign block patterns and variants in call sign make up, in saying that, around 98% of all DNB's logged comprise of the two x one format (two letters plus one number).
Also the beacons logged on 1922.5 and 1978.5 are not the usual standard DNB. There is no preceding nor ending carrier and there is no two to four minute key on/off period, they are a new type of "Tropical Ocean Tuna Longline Fishing Buoy" made by Ryokuseisha Electronics in Japan, with just a three watt transmitter. They are also restricted to use "Movement Range: Pacific".
Likewise, the two on 2005 (7G and 8F) also exhibit similarities to the two frequencies mentioned above, no preceding/ending carrier, no four minute cycle and appear at random.
So unless you monitor those two frequencies for extended periods you have little chance coming across them by accident. I see to think they are only activated by the Mother Ship using Selcal transmission and thus conserve battery energy. I looked at these beacons on the company website which was in Japanese.