Newington, CT: Home of the ARRL.
ARRL: American Radio Relay League, organization of amateur radio (Ham) operators.
P5: Prefix of call signs in Peoples' Republic of Korea.
4L4: Prefix of call sign for hams in the Republic of Georgia.
P5/4L4LFN: Standard method of designating ham (from Georgia) operating in foreign country (PRK).
SSB: Single sideband. The predominant mode of voice communication on the ham bands.
RTTY: Radioteletype.
QSL: Postcard confirming contact.
QSL manager: Organizes exchange of American QSLs with foreign ham stations.
AO-40: Amsat Oscar 40. A recent satellite for amateur use built by the amateur satellite organizaition AMSAT.
QSO: A conversation or contact between hams on the air.
DX: (Long) distance. Applies to contacts with foreign countries, especially overseas.
DXCC: DX Century Club. An ARRL program awarding a certificate to hams with verified contacts with 100 or more countries or other defined geo-political entities. The DXCC Honor Roll lists the hams with contacts with the most countries. Although there are currently 334 entities on the official accepted list, the top hams have about 377 entities to their credit, some of which have been deleted from the accepted list over the past several decades due to political circumstances (e.g., Tibet).