PLT OF SMT CARGO ACFT HAD NMAC.

Narrative

IN STRAIGHT AND LEVEL FLT ON 130 DEG HDG AT 5000 FT. I WAS BEING WORKED IFR BY ZMA. AFTER NORMAL SCAN; I WAS LOOKING OUT THE L SIDE OF ACFT. WHEN I LOOKED FORWARD; THERE WAS AN OBJECT AT MY 12 O'CLOCK POS. I FOCUSED AND SPOTTED IT. IT WAS AN ACFT. THIS SEEMS LOW BUT EVERYTHING TOOK PLACE IN A FEW SECONDS. I IMMEDIATELY BANKED HARD R AND PULLED; THEN BANKED L LOOKING OVER MY SHOULDER AT THE ACFT. IT WAS A SMA WHITE WITH BLUE STRIPES. I CALLED CTR AND TOLD THEM OF A NEAR MIDAIR. HE ADVISED ME THERE WERE NO ACFT NEAR ME. I INSISTED AND HE SAID THERE WAS 1 AT MY 6 O'CLOCK POS AT 3400 FT. I SAID WRONG HE WAS AT 5000 FT. HE THEN SAID THE ACFT IS NOW 5600 FT. HE ASKED IF I WANTED TO FILE A RPT. I SAID MAYBE. I THEN THOUGHT OUT THE SITUATION AND ASKED FOR THE PHONE NUMBER ON THE GND. I WAS IN TOUCH WITH ARTCC CTLR OF ZMA. RPT (RPT NUMBER) ZMA (305) 592-9753. HE PULLED THE TAPES AND FOUND A TARGET WITH NO TRANSPONDER I MISSED; HE SAID. HE DIDN'T KNOW WHY THEY WERE NOT INVESTIGATING AN ACCIDENT IT WAS SO CLOSE. THE CTLR'S SCREEN DID NOT ACCORDING TO HIM DISPLAY THIS ACFT. THERE IS A GREAT PROBLEM WITH FILTERING OUT THESE TARGETS.