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A Northwestern Central DuPage Hospital Mobile Stroke Unit (MSU) ambulance is based out of CDH.  They use the identifier MEDIC 34 on the air and appear to be dispatched by DU-COMM on their Fire North channel (154.175 / STARCOM21 talkgroup 2701).  They often coordinate with other Fire North agencies on the STARCOM21 Fire Ops 3 talkgroup (2719).  They also travel outside of the Fire North area and have access to other area fire dispatch frequencies and talkgroups.