Hadith.866 - Zurarah narrated from Imam Muhammad ibn Ali Al-Baqir (as) that He said
"You may give the adhan (call to prayer) without being in a state of wudu (ritual purity), wearing a single garment, whether standing or sitting, and in any direction you face.
However, when you perform the iqamah (second call to prayer), you must be in a state of wudu, prepared for the prayer."