I’m a ham radio operator (WD5GNR ... shows a voice contact (a QSO) that is difficult to understand using regular analog transmissions, but is perfectly clear using the digital techniques.

Ham radio operators that did “phone” (ham-talk ... [AA6E] made a very informative video where he carries on a QSO (a conversation) with a distant station using freedv. What makes it ...

QSO: ham shorthand for a radio contact, e.g. "I made a 1,000+ mile QSO with a ham who was camping out in Yosemite National Park." QSL: a confirmation of two-way communication between ham operators.