Not to stir the pot, but FWIW
fleetsubmarine.com indicates
SJ RADAR:
The next major advance came with the installation of SJ Radar, beginning in mid-1942. Unlike the SD unit, the SJ was a directional radar, which could be used to sweep the surrounding sea for targets. The primary limitation on range was the height of the retractable mast, radar being limited to line-of-sight.