Shown below, is the list of all of the Amplitude Modulation (AM) stations I have QSO'd with on 160-meters, 75-meters, and 40-meters. They are not part of a formal group, but I call them the "Southwest AM Group" for want of a better name.  They are one of the most friendly, cordial, and helpful collection of hams I have ever met, so if you should run into them on the air, expect a warm, friendly welcome, and coming away with a feeling of having known them most of your life.
        

Southwest AM Group
          
(Arranged alphabetically, by last letters in call sign)
(Last updated 06/15/2009)
          
CALLSIGNNameLOCATION
K7BDYMartinShowlow, AZ
K7CAXMaxPhoenix, AZ
K6CJAKenHesperia, CA
W7CPARandyPhoenix, AZ
N7CXJBruce Payson, AZ
KD7DOJohnBenson, AZ
K7EWEJimTucson, AZ
KB7FDFRichardKearny, AZ
KB7GAIWallyTucson, AZ
W7GMKGaryVail, AZ
K0HGWJohnLa Luz, NM
WD7IHarveySun Lakes, AZ
W7ILWHowardPrescott, AZ
W7ISJJoeTucson, AZ
NI7JRonCave Creek, AZ
K7JEBJimGlendale, AZ
WA6JUSJohnSan Diego, CA
KB7LOQArtPhoenix, AZ
W7MDDamonVail, AZ
K5MELMelRuidoso Downs, NM
WB7ODODennisRichmond, UT
W8OFCJimMarana, AZ
W6OOQBobEscondido, CA
K7POFBobChino Valley, AZ
W8QBGGeorgeMesa, AZ
NA7RHBobScottsdale, AZ
N7SEPBarryTucson, AZ
KO6SMLarryPeoria, AZ
WA6TJNTedE. Hemet, CA
W7TQJBobPrescott, AZ
KE7TRPClarkChandler, AZ
WA8ULGTedScottsdale, AZ
W7UOWesArivaca, AZ
K7VZPBillSun City, AZ
W5WVIJonMesa, AZ
W7XHBillTucson, AZ
W1ZDLockPhoenix, AZ
          
          
AM Times and Frequencies
          
1.885 MHz - Week-end mornings mostly, from 4:30 AM and on until Sunrise
1.917 MHz - Tuesday, Thursday, week-end mornings around 5:00 AM until Sunrise
3.855 MHz - Week-end mornings mostly, around 7:00 AM until whenever
7.293 MHz - week days around 12:00 PM (Noon)