C172 PLT ABORTS TKOF AT AVQ WHEN HE REALIZES ANOTHER C172 IS DEPARTING IN THE OPPOSITE DIRECTION AT A NON TWRED ARPT.

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MY ACFT WAS DEPARTING MARANA NW REGIONAL ARPT AT XA00 ON JAN/MON/05. WE FOLLOWED ANOTHER C172 OUT TO RWY 30 FOR DEP. WINDS WERE OUT OF THE NW AT 10 KTS. THE C172 PULLED INTO A RUN-UP AREA. WE TOOK RWY 30 AFTER I MADE AN ANNOUNCEMENT WE WERE TAKING RWY 30 FOR A R XWIND DEP. AS WE LINED UP ON THE CTRLINE AND APPLIED FULL THROTTLE; I LOOKED DOWN AT THE OTHER END OF THE RWY; THERE WAS A CESSNA DEPARTING RWY 12. I APPLIED MY BRAKES AND ABORTED THE TKOF. (THERE WAS AT LEAST 2500 FT OF SEPARATION.) I HEARD NO RADIO CALLS. THEN AS HE OVERFLEW US; I HEARD HIM SPEAK SAYING 'IS HE ON FREQ?' I BELIEVE MY RADIO WAS NOT ON THE PROPER FREQ OF 123.00. I BELIEVE AT THE TIME OF TKOF THE RADIO WAS SET TO 123.05. AS I ABORTED MY TKOF; I LOOKED AT THE RADIO TO CHANGE THE FREQ TO 123.00. AFTER THIS; I CONTACTED THE OTHER CESSNA TO ADVISE HIM I HAD HIM IN SIGHT AND I WAS ABORTING THE TKOF. THIS EVENT COULD HAVE BEEN AVOIDED BY VERIFYING THE PROPER RADIO FREQ WAS SET IN THE RADIO BY MYSELF AND IF THE OTHER PLT FOLLOWED STANDARD AIM PROCS OF TAKING OFF INTO THE WIND.