KOPB-TV originally signed on the air as KOAP-TV, on February 6, 1961. The call sign letters stood for "Oregon Agricultural Portland", preceded by the K prefix the Federal Communications Commission uses when assigning call signs for stations west of the Mississippi River. It was a sister station to KOAC-TV in Corvallis, Oregon, whose call letterscarried over from KOAC-AM, which received them in the mid-1920s during its early years broadcasting as an AM radio stationstood for "Oregon Agricultural College" (Oregon State University's original name). KOAP-TV was first housed at the campus of Portland State College (now Portland State University), with the transmitter being located on Council Crest. KOAP-TV was a member of NET, or National Educational Television, carrying its programs. On April 30, 1962, KOAP-TV's FM sister service (KOAP-FM) signed on the air. By 1966, most local programs originated at KOAP-TV.