PLT OF C182 TAKES OFF FROM FUL WITHOUT CLRNC.

Narrative

I CONTACTED GND CTL AND REQUESTED AN IFR CLRNC TO CRQ. THE CTLR RESPONDED IMMEDIATELY WITH A CLRNC AND A SQUAWK CODE. I STARTED THE ENG AND REQUESTED A TAXI CLRNC TO RWY 6. THE TWR RESPONDED WITH A TAXI CLRNC TO RWY 6. THE RADIO XMISSION FROM THE TWR SEEMED A LITTLE WEAK; WITH STATIC. I HEARD NO OTHER ACFT ON GND FREQ. I THEN REQUESTED A TKOF CLRNC. I HEARD A SOMEWHAT INTERMITTENT 'NXXX CLRED FOR TKOF.' I REPEATED MY CLRNC TO THE CTLR; 'XXX CLRED FOR DEP; RWY 6.' AGAIN; I HEARD A SOMEWHAT GARBLED 'XXX CLRED FOR TKOF.' I PROCEEDED PAST THE HOLD LINES; ONTO THE RWY; AND ALIGNED THE PLANE WITH THE CTRLINE AND ADVANCED THE THROTTLE. AS I WAS ACCELERATING; I NOTED A SMALL HELI HOVERING IN THE GRASS (OR ASPHALT) AREA BTWN THE RWY AND THE TXWY ON THE S SIDE OF THE ARPT. I CONTINUED MY CLBOUT. AT ABOUT 600 FT AGL INTO MY CLB; 1/4 MI FROM THE ARPT; I HEARD THE CTLR XMIT; 'XXX; DID YOU JUST TAKE OFF?' I REPLIED 'XXX; YES (OR AFFIRMATIVE).' THE CTLR THEN XMITTED; 'XXX; I DID NOT CLR YOU FOR TKOF; SQUAWK VFR; ENTER R DOWNWIND FOR RWY 6.' THE CTLR THEN XMITTED 'XXX; I DID NOT CLR YOU FOR TKOF; I HAVE A HELI ON AN IFR DEP.' I REPLIED; 'XXX; I REQUESTED A TKOF CLRNC; I THOUGHT I HEARD YOU GIVE ME ONE; AND I REPEATED MY CLRNC BACK TO YOU. I THOUGHT YOU CLRED ME FOR TKOF.' HE THEN XMITTED; 'XXX; CONTINUE N OF THE FIELD AND CIRCLE; I'M WORKING ON GETTING YOU A CLRNC.' I CIRCLED TWICE AT 1100 FT AGL; AND THE CTLR XMITTED; 'XXX; EXECUTE A LOW APCH; THEN CONTINUE AS FILED.' I DID SO; AND AFTER THE LOW APCH; CONTINUED MY CLB ON HDG AND ASSIGNED ALT. CONTRIBUTING FACTORS: EXTREMELY CLR WX; VERY LITTLE ACTIVITY AT THE ARPT; RADIO STATIC; AND FAILURE TO CLRLY DETERMINE; WITHOUT A DOUBT; MY TKOF CLRNC. THE FACT THAT I HAD A SQUAWK CODE PRIOR TO TAXI (MEANING THAT I WOULD NOT BE REQUESTING 'READY FOR SQUAWK AND RELEASE.' I USUALLY ASK CTLRS TO REPEAT ANY CLRNC I AM AT ALL UNSURE ABOUT. I ALSO REPEAT EVERY CLRNC; AND WRITE THEM DOWN ON A PAD. MY PERCEPTION WAS THAT THERE WAS NO OTHER ACFT ON THE TXWY; OR IN ANY POS TO TAKE OFF ON THE ACTIVE RWY 6; HENCE; ANY CLRNC FOR TKOF MUST HAVE BEEN DIRECTED AT ME. IT WAS A LITTLE BIT UNUSUAL THAT 2 ACFT; PARTICULARLY THE R22 HELI; WERE DEPARTING IFR IN SUCH BEAUTIFUL WX CONDITIONS. IN OVER 2 DECADES OF FLYING; THIS IS A FIRST. CORRECTIVE ACTION: IT WOULD HAVE BEEN NICE IF THE CTLR HAD NOTIFIED ME THAT THERE WAS HELI ACTIVITY (DURING MY TAXI). THAT WOULD HAVE BEEN HELPFUL INFO (SITUATIONAL AWARENESS). I WAS ALSO SOMEWHAT SURPRISED (IN HINDSIGHT) THAT I WAS ABLE TO TAXI ONTO THE RWY; TAKE OFF; BEGIN A CLB; AND BE 1/4 MI FROM THE ARPT BEFORE THE CTLR NOTICED THE INCURSION. I THINK THE CTLR WAS EITHER WORKING ON MY CLRNC; OR DISTR BY THE HELI HOVERING IN FRONT OF THE TWR. ON A GOOD NOTE; I HAD A 6TH SENSE; SOMETHING TELLING ME TO CHK THE APCH VISUALLY FOR INCOMING TFC BEFORE I TAXIED ONTO THE RWY. IF THERE HAD BEEN AN ACFT ON FINAL APCH; I WOULD HAVE SEEN THEM; AND NOT TAXIED ONTO THE RWY. BECAUSE MOST OF MY FLYING IS IN SOUTHERN CALIFORNIA; I FLY IFR 90% OF THE TIME; FOR EASE OF ROUTING; AND RADAR TA'S. I WILL NOW PAY PARTICULAR ATTN TO MAKING SURE I FULLY UNDERSTAND MY CLRNC; AND INSIST ON HAVING IT REPEATED; IF NEED BE.