The following was written (by me) in response to a recent inquiry from someone unfamiliar with the Seattle radio market, about the origin of the KJR call letters and KJR's claim to bragging rights as Seattle's first radio station:
KJR began before the U.S. entered World War I as amateur station 7AC. All "civilian stations" were barred from broadcasting during The War, but after the war, owner Vincent Kraft applied for a new license and was given call letters 7XC. This was Radio as we know it today, not Ham Radio.
Music programming was banned in 1921 when a new type of radio license was introduced, so Kraft applied and 7XC became KJR.
But the confusion does not end there. In 1941, KOMO bought KJR, and on May 7, 1944, the two stations swapped frequencies, to give KOMO the better frequency (1-B clear channel 1000 KHz).
To those of us who spend time researching histories of radio stations, we tend to follow the license. For example, if a station goes dark and loses its license, and someone else applies for a "new station" on the same frequency in the same community, I would call that the same radio station, from a historical perspective.
Since I don't have access to the FCC records for the period, I cannot say if KOMO is KJR and KJR is KOMO, from a historical perspective. For example, if the owners just applied for changes of call letters, then KJR is the original KOMO. But if the owners applied for simultaneous frequency changes, then KJR really is KJR.
Of course, you can completely ignore the license issue and look at what really happened: KJR and KOMO really did swap frequencies, as each retained their staff and network affiliations through the swap.
As for KJR-FM, what could be cooler than being on 95.7 MHz? They have used old KJR Channel 95 jingles from the 1960s on many an occasion.
But it has not always been thus. The KJR-FM call letters came into being in 1994, were killed in 2000, and reappeared in 2002. 95.7 first came on the air in 1960 as a stand-alone FM owned by IGM (International Good Music), the automation machine maker -- my first paid job in radio included running an IGM machine.