NMAC APPARENTLY CAUSED BY MHT TRACON.

Narrative

MANCHESTER CLRED ME FOR THE VISUAL APCH AT 5 MI W AND 5000 FT. I WAS UNABLE TO COMPLY AND INFORMED THEM. THEY GAVE ME A HDG OF 330 DEGS AND DSCNT TO 2000 FT. WHEN I WAS ABEAM THE OM; THEY TURNED ME IN; AND ALLOWED ME TO SWITCH FREQ. I WAITED UNTIL FREQ WAS CLR AND ANNOUNCED MY POS TO NASHUA TWR WHO WAS SURPRISED AT MY APPEARANCE THERE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES A MOONEY M-20J; COMMUTING FROM NH TO NJ. 'MHT HAS A FEW PROBS;' SAID THE RPTR. MHT APCH SERVES ASH CLASS 'D' AIRSPACE; BUT NOT VERY WELL. IFR ACFT ARE OFTEN BROUGHT TOWARDS ASH AT 5000 FT; TOO CLOSE FOR A REASONABLE APCH. THE RPTR DID NOT SEE A BARON THAT WAS ON THE ILS TO ASH. THE BARON HAD TO TAKE EVASIVE ACTION WHEN THE RPTR PLUMMETED OUT OF THE CLOUDS. WHEN THE RPTR CALLED ASH ATCT OVER THE OM; ASH SAID 'WHAT THE HELL ARE YOU DOING THERE!' MHT HAD NOT FORWARDED THE RPTR'S PROGRESS TO ASH. THE RPTR WENT TO THE ASH TWR TO APOLOGIZE. FROM THE ATCT; HE CALLED MHT. MHT ACKNOWLEDGED THAT THERE HAD BEEN A PROB AND THAT TRAINING WAS IN PROGRESS AT MHT. THE RPTR HEARD THAT HE AND THE BARON HAD MISSED BY ONLY 200 FT. THE RPTR STATES THAT HE HAS SENT 'SEVERAL OTHER RPTS' TO THE ASRS ON THE ATC SYS AT ASH; HIS HOME PORT. HE IS NOW AWARE OF THE FAA AVIATION SAFETY HOTLINE.