APCH CTLR UNABLE TO READ DUE TO ACFT RADIO PROBLEM.

Narrative

ON THIS TRIP I TOOK A FRIEND AROUND BIG SUR TO SEE THE SIGHTS AND EXPERIENCED DIFFICULTY COMMUNICATING WITH MRY APCH. I FIGURED THE CTLR WAS JUST IGNORING ME BECAUSE I WASN'T IFR; SINCE THE RADIOS WERE WORKING FINE AT PAO AND WATSONVILLE. HOWEVER; COMING BACK FROM BIG SUR THE CTLR ACKNOWLEDGED VERY WEAK XMISSIONS FROM AN SMA. SINCE I COULDN'T ESTABLISH COMS I PROCEEDED THROUGH THE TRSA ABOVE THE MRY ATA WITH EXTREME CAUTION. WHEN WE GOT BACK TO WATSONVILLE ANOTHER PLT RPTED THAT MY XMISSIONS WERE VERY WEAK AND SCRATCHY. I DROPPED OFF MY PAX; THEN UNPLUGGED AND STOWED THE SECOND HEADSET TO PRECLUDE COCKPIT CLUTTER. JUST AS I DID THAT THE RADIO VOL CHANGED SIGNIFICANTLY. ON THE RETURN TO PAO THERE WERE AGAIN NO RADIO PROBS WITH MOFFETT TWR OR PAO TWR. WHEN I GOT HOME I TOOK APART THE SECOND HEADSET AND FOUND THAT A WIRE IN THE MIC PLUG WAS SHORTING TO THE CONNECTOR SHELL. THUS; THERE ACTUALLY WAS AN ELECTRICAL PROB AND MRY APCH REALLY COULD NOT HEAR ME. I HAD TROUBLE ONLY WITH THEM BECAUSE THAT WAS THE ONLY TIME THE FAULTY HEADSET WAS PLUGGED IN. LESSON LEARNED: OFTEN THE CTLR IS TRYING TO DO WHAT HE'S SUPPOSED TO AND THE PROB IS SOMEWHERE ELSE.