What Marconi Wrought Last November station KFDA’s Art Holt of Amarillo, Texas set a world’snonstop endurance record for disk jockeys: six days and six nights.Last week Disk Jockey Ray Briem, 26, of Salt Lake City’s KLUB, puttingon LPs for trips to the bathroom and catnaps, spun, gabbed and wheezedhis way to a new record: six days, six nights and six hours.