UNAUTH WRONG RWY LNDG. NMAC ON APCH.

Narrative

I WAS FLYING FROM AIY (BADER FIELD) TO 26N (OCEAN CITY) FOR FUEL. WX WAS VFR. THE TRIP IS APPROX 9 NM AND STARTUP TO SHUTDOWN IS USUALLY 12 MINS. I TUNED IN MY RADIO TO 122.8 AS I APCHED OCEAN CITY AND RPTED MY POS AND ASKED FOR RWY INFO. I RECEIVED NO ANSWER. 20 SECONDS LATER; I HEAR A POS RPT OF AN ACFT 3000 FT DIRECTLY ABOVE OCEAN CITY. I HEAR SEVERAL OTHER ACFT CALLING IN TO OCEAN CITY BUT NO REPLIES. SINCE THE WIND AT BADER WAS FAVORING 22 (WHICH I COULDN'T USE TO DEPART); I DECIDED TO ENTER A R DOWNWIND FOR RWY 24 AT A 45 DEG ENTRY. I'M CALLING OUT MY POS ENTERING DOWNWIND; BASE; AND FINAL WITH NO RESPONSE. I TURN FINAL AT ABOUT 600 FT. I STABILIZE MY APCH AND NOTICE A CESSNA AT ABOUT 400 FT CLBING OUT AT MY 11 O'CLOCK POS ABOUT 400-500 FT TO MY L. I IMMEDIATELY REALIZED THAT THE CESSNA HAD JUST DEPARTED RWY 6 AND WAS UPSET THAT HE DIDN'T RESPOND TO MY POS RPTS AND I COULDN'T UNDERSTAND HOW I COULD HAVE BEEN SO STUPID TO BE IN THIS POS OR WHY SOME IDIOT WAS TAKING OFF ON RWY 6 WHEN I'VE ANNOUNCED MY ENTIRE PATTERN TO EVERYONE. IT'S NOT UNCOMMON FOR UNICOM AT 26N TO NOT ANSWER YOUR INQUIRIES. WHEN I LANDED DOWNWIND; I KNEW I USED THE WRONG RWY. I ORDERED FUEL AND ASKED IF ANYONE USED THE RADIOS AND GOT NO RESPONSE. I STARTED TALKING TO ANOTHER PLT AND HE TOLD ME THAT HE HEARD UNICOM TELLING ME THAT I WAS USING THE WRONG RWY. I ASKED HIM IF HE HEARD MY POS RPTS AND HE SAID 'NO' AND THAT I SHOULD CHK MY COM RADIO BEFORE I DEPARTED. I DON'T KNOW WHY; BUT I TOLD HIM THAT IT WAS WORKING AT BADER AND WHEN I PUT 122.8 IN I HEARD OTHER PLTS TALKING TO OCEAN CITY. HE TOLD ME THE FREQ WAS 122.7 FOR 26N AND I KNEW I SCREWED UP. I HAVE BEEN TO N80 (OCEAN CITY; MD) MANY TIMES AND 26N (OCEAN CITY; NJ) AND 'KNOW' THE FREQS. INSTEAD OF LOOKING AT THE SECTIONAL; I PUT IN THE KNOWN FREQ FROM MEMORY AND WHEN I HEARD OCEAN CITY POS RPTS I NEVER QUESTIONED MY MISTAKE. I WILL ALWAYS DOUBLE-CHK MY FREQS; ESPECIALLY IF I 'KNOW' THEM. UNLESS I'M TALKING TO THE ARPT; I'LL OVERFLY THE ARPT TO MAKE SURE I USE THE BEST (AND ACTIVE) RWY.