SF340 RADIO COM PROB UNABLE TO ESTABLISH RADIO CONTACT LEADS TO A LNDG WITHOUT CLRNC AT PAH; KY.

Narrative

ON AN IFR FLT THROUGH PAH ENRTE TO MEM; DEVELOPED RADIO ANOMALY WITH LOUD SQUEAL FEEDBACK. AFTER DEPARTING; ATTEMPTED OBSERVER'S INTERCOM/HEADSET AND EMER BYPASS ON AUDIO CTL PANEL; THEN REMOVED FO HEADSET/BOOM FROM R SIDE COM JACK. COMS RE-ESTABLISHED AND USED HANDHELD MIKE FOR REMAINDER OF FLT TO PAH UNTIL CLRED FOR VISUAL APCH WITHIN 10 MI OF ARPT. UNABLE TO CONTACT PAH TWR INITIALLY; THEN TRIED HEADSET/BOOM ON CAPT'S SIDE WITH NORMAL OP. PAH TWR INSTRUCTED ME TO RPT 2 MI FINAL; WHICH I ACKNOWLEDGED. I SUBSEQUENTLY RPTED ON FINAL AND HEARD FEEDBACK; THEN ATTEMPTED CALL AGAIN AT APPROX 2 MI FINAL; BUT HEARD NO RESPONSE. ELECTED TO CONTINUE APCH AND LNDG LOOKING FOR LIGHT SIGNAL SINCE I COULD NOT CONFIRM LNDG CLRNC. I TREATED LNDG AS IF NORDO AT CTLED FIELD (CLASS D AIRSPACE). AFTER LNDG AND CLR OF RWY 22; TOOK OFF HEADSET/BOOM AND TRIED HAND MIKE TO RPT CLR OF RWY AND TO TAXI. TWR ACKNOWLEDGED THIS XMISSION; BUT SAID THEY DID NOT HEAR CALL AT 2 MI FINAL. RADIO PROBS PERSISTED WHEN DEPARTING PAH; AND FOUND FO HEADSET/BOOM WAS RECONNECTED. DEPARTED PAH USING HAND MIKE AND AFTER FO HEADSET/BOOM WAS AGAIN REMOVED. ARRIVED AT MEM WITHOUT FURTHER INCIDENT.