NMAC BTWN 2 LIGHT SINGLES AT N46.

Narrative

I WAS FERRYING AN ACFT (CHEROKEE 6) FROM POTTSTOWN MUNICIPAL ARPT TO THE POTTSTOWN-LIMERICK ARPT. I ENTERED THE PATTERN (R DOWNWIND FOR RWY 28) AT PATTERN ALT AND ANNOUNCED MY POS. I AGAIN ANNOUNCED MY POS ON DOWNWIND AT MID FIELD; BASE LEG; TURNING FINAL AND ON SHORT FINAL. ON SHORT FINAL MY PICK UP RIDE ACFT XMITTED OVER THE RADIO (122.7) FOR ME TO 'WATCH OUT FOR THE CESSNA Y.' I LOOKED IN ALL DIRECTIONS AND NEVER SAW Y; AND CONTINUED TO LAND WITHOUT INCIDENT. AFTER LNDG AND TAXIING MY ACFT TO THE MAINT HANGAR; THE LCL POLICE ARRIVED AND PROCEEDED TO TELL ME I HAD 'LANDED WITHOUT CLRNC.' I HAD FOLLOWED ESTABLISHED PROCS FOR DOWNWIND; BASE; FINAL. I AT NO TIME HEARD THE OTHER ACFT Y ANNOUNCE HIS POS OR INTENTIONS. ACCORDING TO WITNESSES; HE CUT IN ON SHORT BASE AND WAS MAKING A HIGH STEEP DSCNT AND WAS GOING TO CUT IN FRONT OF ME. APPARENTLY; THE OTHER PLT SAW ME AND TOOK EVASIVE ACTION. THE OTHER PLT DID NOT RETURN AND LAND AT THE SAME ARPT. I BELIEVE THAT THE OTHER ACFT MAY HAVE BEEN ON THE WRONG FREQ. POTTSTOWN-LIMERICK UNICOM IS 122.7 AND MANY PLTS UNFAMILIAR WITH THE FIELD XMIT ON 122.8. ALL PLTS MUST FAMILIARIZE THEMSELVES WITH ALL ASPECTS OF THE ARPT BEFORE ATTEMPTING TO LAND. IF STANDARD PROCS ARE FOLLOWED; IT IS MUCH EASIER FOR A PLT TO KNOW WHERE TO LOOK FOR OTHER ACFT.