WHILE REPOSITIONING ACFT; 2 MAINT TECHNICIANS TAXIED ACFT ONTO TXWY AND RWY WITHOUT CLRNC.

Narrative

WHILE REPOSITIONING ACFT FROM MAINT HANGAR TO TERMINAL; AREA GND CTL WAS CONTACTED. GND CTL RESPONDED WITH STATEMENT 'RADIO IS WEAK (AND THEN UNINTELLIGIBLE). MECH IN R-HAND SEAT WAS TALKING WITH GND -- THOUGHT CTLR SAID 'PROCEED.' 2 OTHER ACFT WERE THEN CLRED TO TAXI. THESE ACFT WERE BEHIND US. WHILE XING ACTIVE RWY; GND CTL SAID 'WHY ARE THERE 3 ACFT TAXIING ON THE TXWY?' I ONLY CLRED 2 ACFT; NOT 3.' WE TRIED TO CONTACT GND CTL FOR AN EXPLANATION BUT GOT NO RESPONSE. AFTER SHUTDOWN; WE TALKED WITH MECHS OF THE 2 ACFT; ALSO DASH 8'S. THEY SAID THEY NEVER HEARD US ON THE RADIO. AVIONICS TROUBLESHOOT OF #2 COM FOUND FO'S HAND MIKE TO BE INOP OR NOT CLR ENOUGH TO BE HEARD. FO'S MIKE WAS R&R'ED OPS CHKED GOOD. THE FACT THAT 3 ACFT OF SAME TYPE WERE TAXIING FROM SAME LOCATION AT THE SAME TIME PROBABLY MADE THE SIT MORE CONFUSING. THE 2 ACFT BEHIND US WERE CLRED TO TAXI ACROSS ALL TXWYS AND RWYS; WHILE WE IN THE LEAD ACFT WERE NOT. WE WEREN'T AWARE AT THE TIME THAT GND CTL COULDN'T HEAR THE RESPONSE OF THE LEAD ACFT WHEN WE RESPONDED TO 'TAXI AS REQUESTED;' BEFORE WE STARTED. GND CTL THOUGHT THE LAST ACFT IN LINE WAS THE ONE IN ERROR; WHEN IN FACT IT WAS THE FIRST ACFT THAT HAD NOT RESPONDED ON THE RADIO.