SMT INVOLVED IN NMAC BUT NOT AWARE UNTIL CALL FROM ATC.

Narrative

I DEPARTED WESTHEIMER ARPT AT NORMAN; OK; FOR A VFR FLT TO DALHART; TX; ON A HDG OF ABOUT 270 DEGS. AS SOON AS I GOT THE AIRPLANE CLEANED UP; I CALLED OK CITY APCH AND WAS TOLD TO STAND BY THAT THEY HAD A STUCK MIKE. I LEVELED OFF AT 3000 MSL AND STAYED ON A HDG OF ABOUT 270. WHEN I WAS ABOUT STRAIGHT S OF WILL ROGERS ARPT THE CTLR CALLED ME BACK TO GIVE ME A SQUAWK CODE AND TOLD ME TO MAINTAIN 3000. THE NEXT CONTACT I HAD WITH HIM WAS TO RPT TFC AT 12 O'CLOCK AND 5700; AN AIRLINER INBOUND. I RPTED HIM IN SIGHT. THE NEXT CONTACT WAS AT ABOUT 30 MI OUT TO CANCEL RADAR; CHANGE FREQ; AND CLB ON COURSE. AND GIVE MY NAME AND PHONE NUMBER; WHICH I DID. LATER I GOT A CALL FROM OKC APCH WANTING MY SIDE OF WHAT HAPPENED. I DID NOT KNOW THAT THERE WAS A NEAR MISS; I DID NOT SEE THE OTHER PLANE; AND APCH DID NOT TELL ME ABOUT HIM. APCH SAID THAT AN LTT WAS ON FINAL FOR WILL ROGERS 35 AND WE HAD A NEAR MISS. IN THE TELEPHONE INTERVIEW; THE MAN KEPT LEADING THE CONVERSATION TRYING TO TELL ME THAT I SAW THE OTHER PLANE; AND HOW CLOSE I WAS TO HIM. HE ALSO DID NOT SEEM TO BELIEVE THAT I HAD MADE CONTACT WITH OKC APCH; AS SOON AS I COULD AFTER TKOF FROM NORMAN. AS FAR AS I KNOW; I FOLLOWED PROC.