AN ACR MLG CAPT RPTS THAT HE HAD A TEMPORARY LOSS OF COM WITH EWR TRACON DEP CTL.

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ON RADAR VECTOR AND INTERMEDIATE LEVEL OFF AT 6000 FT MSL; ROUTINE FREQ CHANGE RESULTED IN NO COM. RETURN TO PREVIOUS DEP FREQ ALSO RESULTED IN NO COM. TRIES OF BOTH FREQS ON ALL 3 AVAILABLE COM RADIOS (6 CTL WINDOWS) YIELDED SAME RESULTS. THERE WAS NO CARRIER OR MODULATION ON ANY COM RADIO ON THE ASSIGNED FREQS AND NO AUDIO FEEDBACK FROM SPEAKERS OR HEADSETS WHEN XMISSIONS WERE ATTEMPTED USING BOOM MIKE AND HANDSET MIKES. INITIAL IMPRESSION WAS THE POTENTIAL OF A TOTAL LOS COM SIT; POSSIBLY FROM ACFT COM SYS FAILURE. SET XPONDER CODE 7700 (7600 MOMENTARILY); MAINTAINED VECTOR HEADING AND MONITORED TCASII DISPLAY/VISUAL FOR POTENTIAL TFC CONFLICT. CHKS FOR OBVIOUS CAUSES (CIRCUIT BREAKERS; SWITCHES; ETC) INDICATED NORMAL. ALL 3 VHF COMS APPEARED 'DEAD' IN XMIT AND RECEIVE MODES ON THE DEP CTL FREQS. CONSIDERATION WAS GIVEN TO THE CONTINGENCY OF A COM-OUT RETURN TO EWR; WHILE INITIATING CHKS OF LCL CTL FREQS. RADIO CONTACT WAS RE-ESTABLISHED ON A EWR APCH CTL FREQ (128.55) AND SUBSEQUENT COMS CONFIRMED THAT OUR 7700 XPONDER CODE HAD BEEN OBSERVED AND THE LOST COM SIT HAD DEFINITELY CAUSED 'NO ATC PROBS.' QUICK CHKS OF ALL VHF COM RADIOS WERE GOOD. ATC INDICATED THAT IT WAS A RADIO FREQ PROB AND NOT AN ACFT SYS MALFUNCTION.