B737 CREW LOSES COMS WITH ZOA N OF BTY AT FL290.

Narrative

AFTER DEP; WAS HANDED OF TO ZOA AND CLRED DIRECT TO CLOVIS; THEN ANOTHER HDOF TO ZOA. 2 ACFT DURING THE NEXT SEVERAL MINS ASKED OAK TO REPEAT THE ALTS THEY WERE CLRED TO. THE CTLR WAS COMING IN BROKEN. WHILE ENRTE FROM BIH (BISHOP) TO LIDAT; OAK SAID TO REMAIN ON PRESENT HDG AND NOT TO EXCEED 280 KTS. WE COULD SEE ON TCAS THAT ANOTHER ACFT WAS BEING VECTORED IN FRONT OF US ON THE ARR. AFTER A WHILE THE FO AND I QUESTIONED JUST HOW MUCH SPACING THE CTR WAS GOING TO GET. IT WAS THEN WE BOTH REALIZED WE HAD NOT HEARD FROM CTR IN A WHILE. I KNEW WHERE WE WERE AND THAT WE HAD RESTR AIRSPACE IN FRONT OF US. THE FO THEN TRIED TO CONTACT OAK. THEN A CIVIL ACFT TRIED TO RELAY A FREQ THROUGH CTR. WE COULD NOT HEAR THE CTR'S XMISSIONS AND THE CIVIL ACFT XMISSIONS WERE VERY BROKEN. I GOT ON THE #2 RADIO AND CONTACTED JOSHUA CTL AND I HAD NO PROBS CONTACTING THEM. JOSHUA WAS IN THE PROCESS OF IDENTING US WHEN DISPATCH SENT US A MESSAGE WITH A ZOA FREQ OF ZZZ. WE CONTACTED THEM AND THEY GAVE US A 180 DEG L TURN. OAK SAID THEY HAD TRIED TO CONTACT US ON THE OLD FREQ AND GUARD. WE TOLD THEM WE NEVER HEARD ANY OF THEIR XMISSIONS AND HAD CONTACTED JOSHUA CTL. NOTHING MORE WAS SAID ABOUT IT; AND THEY CLRED US LIDAT-BTY AND THE ARR. 1) ALTHOUGH INITIALLY WORRIED; I'M SURE OUR RADIOS WORKED FINE THE ENTIRE TIME. 2) I KNEW WHERE WE WERE AND THAT WE NEEDED TO TURN SOON. 3) I CONTACTED OUR ATC SPECIALIST ON ARR IN LAS. WITHIN MINS HE CALLED BACK AND ASSURED US THE OAK HELD NO CULPABILITY TOWARDS OUR FLT. AS ALWAYS; AN OUTSTANDING JOB. 4) DISPATCH (AND ACARS) PLAYED A QUICK; EFFICIENT ROLE IN RESOLVING THE PROB. LESSONS: 1) SINCE WE WERE LETTING THE CTR BUILD SPACING; WE DIDN'T QUESTION NOT HEARING FROM THEM FOR A LONGER PERIOD OF TIME THAN WE PROBABLY SHOULD HAVE. 2) SINCE WE DON'T HAVE GUARD; GOING TO IT INSTEAD OF JOSHUA MIGHT HAVE PROVIDED A QUICKER RESOLUTION TO THE PROB.