SMA ON PRACTICE APCH HAS NMAC.

Narrative

FLYING UNDER SIMULATED INST CONDITIONS (FOGGLES) WITH CFII IN R SEAT; WE HAD DSNDED IN THE HOLDING PATTERN FROM 4500 FT TO 3000 FT. SOCAL APCH WAS BEING MONITORED AND I HAD NOTICED THAT AN ACFT WAS REQUESTING THE VOR 'A' APCH AT OCN. THE FLT INSTRUCTOR AND I WERE NOT PAYING VERY CLOSE ATTN TO THE RADIO CALLS TO THIS ACFT. AFTER COMPLETING OUR HOLDING PATTERN PRACTICE AT 4500 FT; THE CFII SUGGESTED I DSND TO A LOWER ALT AND OBTAIN A POP UP CLRNC FROM SOCAL APCH. SHORTLY AFTER MAKING RADIO CONTACT WITH APCH CTL; THE CTLR CALLED OUT TFC AT 11 O'CLOCK AND LESS THAN A MI TO THE OTHER ACFT HE WAS WORKING. I KNEW THAT THE TFC HE WAS TALKING ABOUT MUST BE US; SO I REMOVED MY FOGGLES AS THE CFII TOOK EVASIVE ACTION. I VIEWED THE HIGH WING ACFT PASS APPROX 200 FT BELOW FROM MY 10 O'CLOCK POS. CONCLUSIONS: SHOULD NOT LEAVE A HIGHER ALT FOR THE PUBLISHED APCH ALT PRIOR TO ESTABLISHING RADIO CONTACT WITH APCH CTL FACILITY. THE CTLR'S WORKLOAD SEEMED AVERAGE TO ME; SO I'M NOT SURE WHY WE WERE NOT NOTIFIED EARLIER ON RADAR PRIOR TO OUR INITIAL CALL. WE WERE SQUAWKING VFR MODE C UP TO THIS TIME.