RTV Slingeland is the local radio station for Winterswijk. They broadcast on 105 MHz with 100 Watt. Peter van der Wel was so kind to confirm my report.

QSL RTV Slingeland, local radio for Winterswijk on 105 MHz

On the internet I learned that RTV Slingeland became been part of 1Achterhoek. 1Achterhoek Radio was a merger between Gelre FM, A-FM (from Aalten) and what was then called Slingeland FM. Leuk FM is now also part of 1Achterhoek. One of the reasons was that stand alone operation became to costly. And the merger is in line with the Dutch strategy to move from local to fewer regional radio stations.

But already in 2023 RTV Slingeland left 1Achterhoek following a dispute over program content. Apparently they are looking for other partners now. RTV Slingeland is named after the little river Slinge, south of Winterswijk.