For the most part, the KT-76C is a direct fit and form replacement for the KT-76A. However, there are considerations when replacing a KT-76A that was installed into a 28V aircraft installation. The original KT-76A utilized a voltage changeover (i.e. dropping resistor) kit for the KT-76A to be installed to a 28V installation.  The KT-76C was designed to operate from any input voltage of 11-33 VDC.  Therefore, the dropping resistor is not needed for the KT-76C in a 28V aircraft. The original droppiong resistor is removed from the original KT-76C wiring harness. In addition, the harness fuse needs to be changed from 3A to 5A. If an RFI suppression adapter was installed originally, then it must be removed as well.