2 SMAS HAVE CLOSE NMAC IN THE TFC PATTERN.

Narrative

WHEN APPROX 20 MI SSW OF DTO I STARTED TO MONITOR UNICOM FREQ. THERE WERE 2 ACFT IN THE TOUCH-AND-GO PATTERN AND A JET PREPARING TO DEPART. WHEN I WAS APPROX 5 MI SSW I RPTED MY POS AND THAT I WAS GOING TO CROSS MID-FIELD AND ENTER L DOWNWIND FOR RWY 17. AS I WAS APCHING MID-FIELD; ONE OF THE ACFT IN THE TOUCH-AND-GO PATTERN ANNOUNCED HE WAS ON XWIND LEG. I SAW AN ACFT ON XWIND AND RADIOED THAT I HAD HIM IN SIGHT AND THAT I WOULD ENTER DOWNWIND IN FRONT OF HIM. AS I RAN THE BEFORE LNDG CHKLIST AND CONFIGURED THE AIRPLANE FOR THE LNDG I LOST SIGHT OF THE TFC. WHEN TURNING DOWNWIND MY PAX POINTED OUT AN ACFT JUST ABOVE AND BEHIND ME VERY CLOSE. I MADE AN IMMEDIATE L DSNDING TURN AND HEARD A RADIO CALL 'ACFT ON DOWNWIND WHAT IS YOUR POS?' I INFORMED HIM I WAS IN A L DSNDING TURN JUST AHEAD AND BELOW HIM. I CONTINUED THE L TURN TO BASE LEG AND MADE A SHORT APCH AND LANDED WITHOUT FURTHER PROBS. IN REFLECTING ON THIS EVENT; SINCE I HEARD NO ACKNOWLEDGEMENT OF MY INTENTIONS TO ENTER THE DOWNWIND IN FRONT OF THE XWIND ACFT AND NO COMS THAT HE HAD ME IN SIGHT; I SHOULD HAVE WIDENED OUT AND FOLLOWED HIM IN THE PATTERN. COMS ARE A 2-WAY STREET.