Public Radio Capital is working to keep an FM station it owns in Tacoma, Wash., on the air after June 30, when Seattle’s KUOW will stop programming it. In six years of operating as an internationally focused alternative to KUOW, KXOT failed to attract enough new listeners to support its operations. PRC is negotiating with National Cooperative Bank, which backed the brokerage’s $5 million purchase of KXOT-FM in 2003. Payments on the loan have stopped while PRC tries to come up with a plan for KXOT. When KUOW began managing the Tacoma station in 2006, its leaders hoped to buy it.