D-Link KX-TDA100 - Manual (Page 165)

2.8 Connection of DECT Portable Stations
Installation Manual 165
For the KX-TDA0142CE User only:
3. Wrap the cable once around the ferrite core. Then close the case of the ferrite core.
Note
If you need to open the ferrite core, use a flathead screwdriver to unlatch the case of the ferrite core.
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