PLT FLYING INTO TMB RPTS ON BASE LEG REQUESTING SEQUENCE. PLT STATES HIS INITIAL CALL WAS 8 MI AWAY. CTLR BELIEVES HIS XMISSION MAY HAVE BEEN BLOCKED.

Narrative

LNDG/DEPARTING RWY 13. LESS THAN 10 ACFT ON FREQ. NUMEROUS XMISSIONS BLOCKED/STEPPED ON DUE TO POOR RADIO DISCIPLINE BY PLTS. C172 1/2 MI N OF FIELD HDG SW DIRECTLY AT ACFT ON 1 MI FINAL; MAKES FOLLOWING XMISSION: 'TWR; CESSNA; I'M ON BASE; WHAT'S MY SEQUENCE?' (FIRST CALL). I ISSUED TURN INSTRUCTIONS TO AVOID CONFLICT AND ASKED C172 HIS INTENTIONS (FULL STOP; TOUCH-AND-GO; ETC). C172 SAID HE ALREADY TOLD ME HE WAS FULL STOP. I TOLD HIM THE FIRST CALL I RECEIVED WAS HIS CALL FROM BASE. C172 SAID HE CALLED XING THE SHORELINE (8 MI E) AND OVER STANDARD VFR RPTING POINT 3 MI E. I RECEIVED NEITHER CALL; AS THEY WERE MOST LIKELY BLOCKED. C172 OBVIOUSLY RECEIVED NO ACKNOWLEDGEMENT; AND ENTERED CLASS D AIRSPACE WITHOUT ESTABLISHING 2-WAY COMS. AT LEAST 1 OTHER ACFT ON FREQ AT THE TIME ADMITTED TO MAKING INITIAL CALL WITH VOLUME TURNED DOWN. RECOMMENDATIONS FOR CORRECTION: PLACE GREATER EMPHASIS ON GOOD RADIO DISCIPLINE DURING EARLY STAGES OF FLT TRAINING. REINFORCE WITH PLTS THE REQUIREMENT TO ESTABLISH AND MAINTAIN 2-WAY COM BEFORE ENTERING THE AIRSPACE. FAR TOO MANY XMISSIONS ARE BEING STEPPED ON BY PLTS WHO TURN DOWN THEIR RADIO VOLUME OR ARE SIMPLY NOT LISTENING.