[RTTY] Odd RTTY signal, 3 pair of tones w/ 3 diff shifts

[Art Searle W2NRA]

A strange thing happened in the Tara Grid Dip contest.  I was tuning down in frequency when I came across a signal that was 350 Hz shift.  I set my shift to 350 Hz and could copy him fine.  Later I came across a shift that was 240 Hz and the signal was reversed.  A little further down the band I found 6F75A transmitting with a normal signal calling CQ.  I opened up my bandwidth and could see 3 pairs of RTTY tones with 3 different shift.  You could see all 3 signals in sync as 6F75A transmitted.  Anyone ever see anything like this before?

73 Art W2NRA
"Keep to the Code!"
w2nra.com