CHART OF CQx LETTERS:
North American HSMS calling frequencies: 50.300 MHz, 144.100 MHz	
A	1	F	6	K	11	P	16	U	21	Z	26	
B	2	G	7	L	12	Q	17	V	22			
C	3	H	8	M	13	R	18	W	23			
D	4	I	9	N	14	S	19	X	24			
E	5	J	10	O	15	T	20	Y	25			
Usage of CQx Letter System: 
Calling CQJ on 144.100 MHz means you will listen for replies on 144.100 MHz + 10 kHz or 144.110 MHz.
Calling CQM on 144.110 MHz means you will listen for replies on 144.110 MHz + 13 kHz or 144.123 MHz.	
When you hear a reply on your listening frequency, immediately shift your transmitting frequency to that frequency and continue your QSO. When finished, you may call QRZ on your listening frequency, or return to your CQ frequency and resume CQing for another QSO. 	
Note: The use of listening frequencies close to 144.100 should be avoided to reduce the possibility of QRM from other stations calling CQ on 144.100.	

REQUIREMENTS FOR A QSO: 
An exchange of both call signs, an exchange of some type of report, and an exchange of confirmation of the same.	
When a station copies :	he sends:	
both calls	both calls & report: W8WN KOØU 27 W8WN...	
both calls & report	R & report:              R 26 R 26 R 26 R ...	
R & report	Rs:                          RRRRRRRRRRRRRRRRR...	
a pair of Rs (you must have at least two to be sure!)	QSO is officially complete	
However, the other station may not know this;	So it is customary to then send "73" to let the other station know that he may QRT.	
73	he may QRT	
A typical exchange:	
W8WN calls CQ for one minute on 144.100:                CQJ W8WN CQJ W8WN CQJ W8WN...	
N1BUG calls W8WN for one minute on 144.110:          W8WN N1BUG W8WN N1BUG W8W...	
W8WN copies N1BUG calling on 144.110; so he shifts his transmitter frequency to 144.110 and sends calls and report to N1BUG for one minute on 144.110 Mhz:   N1BUG W8WN 27 N1BUG W8WN...	
N1BUG copies both calls and the report and sends, for one minute and with no calls:
                                                                                R 26 R 26 R 26 R 26 R ...	
W8WN copies R and report and sends, for one minute:  RRRRRRRRRRRRRRRRRRRRRRRR...	
N1BUG copies R's, and the QSO is complete. Note that if N1BUG has not copied Rs, he would continue sending R 26 R 26, etc. so that W8WN will keep sending R’s. Otherwise, N1BUG may stop transmitting at this point.
If reflections are good, N1BUG may send 73 during the next transmitting sequence or two to tell W8WN that he has everything.	
W8WN copies the 73s or does not hear N1BUG any longer, so W8WN quits sending and completes his log sheet.  (He may also wish to send 73, or QRZ before returning to 144.100 to call CQ again).	

MISSING INFORMATION:
On high-speed CW MS operation, it is possible to request a missing piece of information.	
BBB	Both callsigns needed	
MMM	My callsign needed	
YYY	Your callsign needed	
SSS	Signal Report Needed (Note: Signal Report is your grid in the NA HSMS Contest)	
UUU	Your keying is Unreadable	
When used, nothing but the appropriate string of letters is sent. The other operator should respond by sending only the requested information. When the requesting station has the needed data, he returns again to the proper exchange sequence.	
TNX to W8WN for writing the original HSCWOP.DOC from which these tables are adapted.