We would like to thank Garret Cotter, Richard Saunders and Arno Schoenmakers for useful discussions. and Ignas Snellen for reducing the ISIS spectrum. We acknowledge support from all EU twinning project, funding from the high z programme subsidy granted by the Netherlands Organization for Scientific Research (NWO) and a NATO research grant. The WSRT is operated by the NFRA with financial support from NWO.