[CQ-Contest] CW Exchange

[n4dxi@arrl.net]

During the CQ WW DX there was a lot of QRN and QRM....exchange was 
something like...

Me....S & P up the band, hearing a DX in an exchange, checking he's not 
a dupe, waiting, then....

DX:   "...TU"  at 35 wpm machine gun cw.

Me: "N4DXI"  at 20 wpm contest slow.

DX: "N4DX(crackle pop) 5NN 3A"  still at light speed but I really don't 
expect him to slow down.

Me:  Did he get my call or not?  Sounds like he missed it so I reply, 
not wanting to break his rythm, I repeat my call and add my exchange.

        "N4DXI 5NN 5"

DX: "TU"

Unfortunately, I still don't know if he got my call.  I guess I could 
have just come back with my call and forced him to reply with my 
call....but if he had it right in the first place, he'd think I was a 
lid or be confused
or he may have already gone to the next call.

Because I sent my call again, do I trust him to get it right without
his acknowledgement?  I especially want him to get my call correctly 
for later LOTW match and my growing DXCC count.

What's the best way to handle this situation?

73....John Bescher, N4DXI