CREW OF B727 VICINITY OF MAJ WORKING THROUGH SAN FRANCISCO COMMERCIAL RADIO FOR DSCNT CLRNC BECAME EXASPERATED BECAUSE OF POOR RADIO RECEPTION AND EXCESSIVE DELAYS RECEIVING REPLIES.

Narrative

AFTER STARTING DSCNT TO MAJ WITH CRUISE CLRNC; SAN FRANCISCO COMMERCIAL RADIO CALLED WITH CLRNC TO FL210; NO XING RESTRS; HOWEVER; CRUISE CLRNC WAS NOT CANCELED. DUE TO HF RADIO COMS BEING DIFFICULT TO UNDERSTAND (SCRATCHY RADIO) AND THE DELAY IN RELAYING REQUESTS -- OR EVEN JUST A REPLY FROM COMMERCIAL RADIO; A COUPLE TIMES WE THOUGHT COMMERCIAL RADIO HAD NOT HEARD OUR REQUEST -- IT TOOK SO LONG TO GET A READBACK. ONE OTHER ACFT CALLED COMMERCIAL RADIO WITH A POS RPT; WHICH HE ALLOWED IN FULL; APPARENTLY FORGETTING WE WERE HAVING A CONVERSATION WITH HIM. WHEN ATC FINALLY CONFIRMED THE CRUISE CLRNC WAS CANCELED; WE WERE BELOW FL200 AND SO CANCELED IFR (PER OUR OPS SPECS). COMMERCIAL RADIO CONFIRMED CANCELLATION OF IFR; THEN CALLED BACK LATER WITH CLRNC TO DSND TO FL200. WE THEN RECONFIRMED WE HAD ALREADY CANCELED IFR. CONFUSION AROSE FROM DIFFICULTY IN UNDERSTANDING HF RADIO WHETHER INITIAL CLRNC WAS DSND AND MAINTAIN FL210 OR CALL DSNDING THROUGH FL210; WITH NO CANCELLATION OF CRUISE CLRNC; EXASPERATED BY EXCESSIVE DELAY IN GETTING REPLIES FROM COMMERCIAL RADIO.