A B767-400 WAS DISPATCHED IN NON COMPLIANCE WITH THE INCORRECT HIGH FREQ ANTENNA COUPLER INSTALLED. DIGITAL COUPLER REQUIRED. ANALOG COUPLER INSTALLED.

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DURING A PREFLT CHK; THE L HF SYS WOULD NOT TEST CORRECTLY ON A B767-400 ACFT. MAINT CTLR ADVISED THE HF COUPLER WAS AT FAULT; BUT A -003 DIGITAL COUPLER WAS NOT AVAILABLE. AFTER CHKING THE IPC FOR A POSSIBLE QUALIFIED INTERCHANGEABILITY PART (QUALIFIED I/W DATA); I DETERMINED THAT A -001 ANALOG COUPLER COULD BE INSTALLED. COUPLER WAS INSTALLED AND BOTH SYS CHKED GOOD. PAPERWORK WAS COMPLETED AND ACFT DEPARTED AND NO HF PROBS WERE EVER ENCOUNTERED DURING ANY FLT PHASE. AFTER THE ACFT ARRIVED AT THE NEXT STATION (ONLY 1 FLT LEG) AND WITH NO INBOUND WRITE-UPS; OUR AVIONICS ENGINEERING DEPT ADVISED THEY HAD DONE SOME RESEARCH AND THE PART SHOULD NOT BE INSTALLED SINCE THE R SYS HAD A DIGITAL COUPLER AND THE L HAD A ANALOG COUPLER (MIXED COUPLERS). ONLY OUR B777 HAS AN SUPPLEMENTAL TYPE CERTIFICATE TO HAVE MIXED COUPLERS NOT THE B767-400. I MADE A MAINT SET-UP AND HAD THE ARR STATION REMOVE THE ANALOG COUPLER; SO WE HAD A MATCHED SET INSTALLED. THE ANALOG COUPLER WAS REMOVED AFTER 1 FLT LEG. I THEN ADVISED THE MAINT CTLR THAT I HAD MADE A MISTAKE IN READING THE INTERCHANGEABLE DATA AND IT WAS MY FAULT. I HAVE ADVISED MY SUPVR THAT WE NEED TO HAVE A READ AND SIGN SENT OUT; SO ALL MAINT CTLRS ARE AWARE OF WHAT TYPE OF COUPLER CONSIGNS ARE ALLOWED AND WHAT SHOULD AND SHOULD NOT BE INSTALLED ON A B767-400 ACFT. NOTE: WE CAN HAVE 2 ANALOG COUPLERS INSTALLED OR 2 DIGITAL COUPLERS INSTALLED; BUT NOT A MIXED SET. I HAVE ALSO ADVISED OUR ENGINEERS TO SPEAK WITH THE VENDOR; SO A SUPPLEMENTAL TYPE CERTIFICATE CAN BE OBTAINED; SO WE HAVE MORE FLEXIBILITY IN AN ACFT ON GND SIT IN THE FUTURE ON THE B767-400 ACFT. I AM ALSO WORKING ON GETTING THE IPC QUALIFIED I/W DATA CHANGED; SO THERE IS NO QUESTION AS TO WHAT CAN AND CANNOT BE INSTALLED.