THE COMBINATION OF A MALFUNCTIONING RADIO AND POSSIBLE CTLR TRAINING IN PROGRESS MAY HAVE LED TO A RWY INCURSION.

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AT SCOTT AFB; IL (BLV) DURING PRE-TAXI PHASE IN A C172; ACFT X; I TUNED THE #1 RADIO TO 119.2 AND CALLED GND CTL (GC). AFTER NO RESPONSE I CHKED THE AUDIO PANEL SWITCHES; INTERCOM AND VOLUMES; HEADSET AND PUSH TO TALK JACK CONNECTIONS. AFTER MAKING SEVERAL MORE ATTEMPTS TO CONTACT GC I WENT TO THE PART TIME TWR FREQ 128.25; AND WAS INSTRUCTED TO GO TO 118.65; THE ACTIVE TWR FREQ. I ASKED TWR WHAT FREQ THEY WERE USING FOR GC AND WAS TOLD 'THE USUAL ONE.' I EXPECTED TO HEAR; 'CONTACT GC ON 119.2.' THIS NONSTANDARD RESPONSE SOUNDED LIKE A STUDENT TWR OPERATOR. PREVIOUSLY; AT MONTHLY SAFETY MEETINGS; SCOTT TWR SUPVRS BRIEFED THEY HAVE STUDENTS OPERATING THE TWR. I MADE ANOTHER ATTEMPT ON 119.2 AND AS SOON AS I RELEASED THE PUSH TO TALK BUTTON I WAS RECEIVING A WEAK AND DISTORTED XMISSION; INSTRUCTING 'ACFT X TAXI INTO POS TO RWY 32L.' I READ BACK WHAT I THOUGHT I HAD HEARD AND STARTED TO TAXI. I DID NOT HEAR ANYTHING FROM GC OR TWR UNTIL I CONTACTED THEM AFTER LINING UP ON RWY 32L FOR TKOF CLRNC. WHILE TAXIING I LOOKED SEVERAL TIMES AT THE TWR; AS IT IS IN LINE OF SIGHT WHILE TAXIING. AFTER PASSING THE ILS CRITICAL HOLD SHORT LINE WHERE THE TXWY TURNS AWAY FROM THE TWR I SCANNED THE TFC PATTERN AND BASE LEG FOR ACFT; THERE WERE NONE. I THEN PROCEEDED TO LINE UP ON THE RWY 32L CENTERLINE AND HELD. ONCE STOPPED; I PERFORMED BEFORE TKOF CHKS AND ATTEMPTED TWICE TO NOTIFY THE TWR I WAS READY FOR TKOF AND REQUESTED A STRAIGHT OUT DEP. AFTER A PROLONGED PAUSE TWR CAME BACK AND DIRECTED ME TO TAXI OFF THE RWY TO AN ADJACENT TXWY. AT THIS TIME I BELIEVED EITHER MY #1 RADIO WAS OPERATING INTERMITTENTLY OR THE TWR RADIO WAS HAVING PROBS. I THEN SWITCHED TO THE #2 RADIO AND HEARD TWR IN THE MIDDLE OF A XMISSION INSTRUCTING ME TO TAXI PAST THE HOLD SHORT LINE. I BELIEVE THE COM SYS NEEDS TO BE THOROUGHLY CHECKED ON THIS AIRPLANE. SEVERAL MINS LATER; THE TWR CLRED ME FOR TKOF AND ASKED WHO GAVE ME PERMISSION TO TAXI IN POS AND HOLD. I RESPONDED; 'YOU DID.' A FEW SECS AFTER THAT TWR RESPONDED NO SIR! CONTRIBUTING FACTORS: PLT DID NOT CHALLENGE NONSTANDARD PHRASEOLOGY. TWR DID NOT COMMUNICATE OR USE THE LIGHT-GUN WHEN OBSERVING THE ACFT CROSS THE HOLD SHORT LINE AND LINE-UP ON THE RWY AND ONLY COMMUNICATED WHEN I CONTACTED IT FOR PERMISSION TO TAKE OFF.