What was found
(CAN) ACFT LOST ALL RADIO COMMUNICATION IN FLIGHT. AN EMERGENCY WAS DECLARED. CREW USED SEL-CAL TO COMMUNICATE WITH MAINTENANCE CONTROL AND MCC COMMUNICATED WITH TOWER FOR LANDING APPROVAL AND INSTRUCTION, ACFT LANDED SAFELY. ROOT CAUSE WAS CONTAMINATION ON THE RCAU CONNECTOR DESCRIBED AS "SOME TYPE OF OIL" AND THE RCAU CONNECTOR WAS DAMAGED. ALSO, THEY FOUND THE NR 2 VHF COMM ANTENNA GASKET STILL HAD THE PROTECTIVE PAPER INSTALLED. RCAU CONNECTOR REPLACED.