what does "portable DCN set" mean?
In Lady Birds car no one spoke or moved between the hospital and the airport. In the cruiser ahead, Youngblood, using the portable DCN set which still dangled from his shoulder by its leather strap, radioed ahead to Paul Glynn, Johnson's valet, telling him to move all Johnson luggage from 86970 to 26000—the first notice to anyone at the field of the aircraft switch—and in the car behind Mrs. Johnson, Liz Carpenter, the only writer present, made the first notes for the statement which the President eventually would have to make to the American people. She had scarcely begun when the cars braked.