Yes. Southeast Aerospace recommends that Service bulletin 1 and 2 be complied with on the KA-120 when the adapter is being installed on a new installation.

Service Bulletin 1 corrects an impedance mismatch between the new generation KX-155 and KX-165 Nav/Comms that utilize surface mount technology. KA-120 with serial number 1845 and above have Service Bulletin 1 incorporated during original manufacturing. The cost to add SB 1 is approximately $200.

Service Bulletin 2 corrects a serial tuning bus incompatibility when interfacing the KA-120 with a KX-125 and with new generation KX-155 and KX-165 surface mount units (post Mod 16 units). KA-120 with serial number 2819 and above have Service Bulletin 2 incorporated during original manufacturing. Honeywell does offer warranty credit for any KA-120 S/N 2818 and below that requires this modification. An authorized Honeywell Service Center must perform the modification and submit the warranty claim.