Title: ARRL's VHF digital handbook
Subjects: Amateur radio, Manuels d'amateurs, Radio, Radio wave propagation, Amateurs' manuals, Shortwave radio, data, tnc, frame, packet, radio, repeater, aprs, hsmm, call, link, call sign, hsmm radio, amateur radio, data unit, packet radio, bit set, call signs, spread spectrum, sequence number, sound card