Jonas Asplund, was a farmer, a pilot . . . as well as a ham radio operator, call sign W71G.
QSO commonly refers to the contact between two amateur radio stations. Jonas mailed this proof of contact out to Frank Taylor of McLeansboro, Ill. stating contact was made September 27, 1948 at 10 am.
Amateur radio was quite popular in 1948 judging by this 1948 cover of Radio News.
Images of card courtesy of Diane Mettler.
Click on images to enlarge.