Here is the way I remember it:
During the entire tenure of NIS, NBC's O&O station in NYC, WNWS(FM) carried the network because they chose not to blow up their powerhouse AM station on 660, and the Miami affiliate was "WINZ News Radio". Stations with the same base call letters had to have overlapping coverage areas and be co-owned.
When the network folded, WINZ remained news for a while, but went increasingly talk.
Alan Courtney, Allen Burke, Larry Kent are three names that ring bells.
Dick Caspar, who might have been involved with the original NIS concept, acquired the legal right to use the sounders on Miami's WNWS, but only after the network had gone dark. WGBS (now WAQI) had also been involved.
BTW...In researching this reply, I learned that Alan Courtney had been a NYC DJ and had co-written Les Brown's 1941 pop hit song, "Joltin Joe DiMaggio.