| The N3PX.com web site is the information center for the Southern Patuxent
Radio Club (which is the longest continually running club in Calvert county, MD) and the Calvert Amateur Radio Club located in southern Maryland. The two sister clubs, with over 100 members, sponsor the N3NO 145.350 (-,156.7) wide area repeater in Prince
Frederick, MD that covers approximately 60 air miles (or about 11,500 square miles) in MD,DC and VA and the N3PX 147.195 (+) D-Star repeater in Hollywood, MD that covers St. Mary's county as well as middle to southern Calvert.
The clubs also sponsor the Southern Maryland Link System that connects the 145.350 repeater in Prince Frederick to the 146.896 (+,146.2) near Montross, VA with a UHF backbone system.