Detect repetitive units within signals
Your repetitive signal seem to be in a lower rate than the noise. I would run an FFT (why short) on all 6 sequences and filter out (zero) the frequencies that are clearly attributed to noise and then run an inverse FFT. 
If you know the repetition rate you might select the one frequency that has the correct information and use the phase information to locate the desired pick. I will try to include exactly 20 cycles if possible (or 16 or 32).