Here's the manual.
http://pdf.crse.com/manuals/3293641311.pdf
"Before you can receive DAB, you must complete the DAB Automatic Scan procedure (see “Before using the system”).
1 Select “TUNER DAB,”“TUNER FM” or “TUNER AM.” Press FUNCTION +/ (or FUNCTION on the unit)
repeatedly. You can also select DAB directly by pressing DAB AUTO SCAN on the unit.
2 Select the tuning mode.
Press TUNING MODE repeatedly until “AUTO”
appears.
3 Tune in the desired station.
Press +/ (or TUNE +/ on the unit) . Scanning stops automatically when a station is tuned in, and then “TUNED” and “STEREO” (for stereo programs only) appear."
"With a DAB external antenna (not supplied), you can obtain higher DAB broadcast sound quality. We recommend that you use the supplied FM/DAB lead antenna only temporarily until you install a DAB external antenna."
Is an FM/DAB antenna attached (second input down)?