It is permissible for him to call the prayer, and it is not disliked; because it is a remembrance in which purification is recommended, so it is not disliked without it: like reciting the Quran. However, the call to prayer should be repeated with impurity; because the call to prayer is to inform the absent, and some may hear it while others do not, so repeating it is beneficial. See: Fath Bab al-Inayah, p. 1: 208.