What is the main difference between the versions of Mid-Continent MD41 annunciators available?
A normal Annunciator Control Unit (ACU) includes a control and relay assembly. The control portion includes lighted annunciations (words) as well as a switch assembly to activate a relay. The relay assembly provides the electrical transfer of information between a conventional nav (VOR/ILS/GS) and GPS to one Course Deviation Indicator (CDI). The ACU units can be complete with control and relay built into one assembly or they can be separated depending on the part number. Some GPS systems and CDIs include internal relays. Therefore, only a control with switch is required. In this case, you would only purchase the Control Head. Some installations use different custom sizes and styles of annunciator switches. Therefore, in this case, only a remote relay is purchased without a control assembly.
A normal Annunciator Control Unit (ACU) includes a control and relay assembly. The control portion includes lighted annunciations (words) as well as a switch assembly to activate a relay. The relay assembly provides the electrical transfer of information between a conventional nav (VOR/ILS/GS) and GPS to one Course Deviation Indicator (CDI). The ACU units can be complete with control and relay built into one assembly or they can be separated depending on the part number. Some GPS systems and CDIs include internal relays. Therefore, only a control with switch is required. In this case, you would only purchase the Control Head. Some installations use different custom sizes and styles of annunciator switches. Therefore, in this case, only a remote relay is purchased without a control assembly. In addition to variations in switches, relays, and sizes, ACUs are engineered to be compatible with specific GPS systems by different manufacturers. Variations in power input and bezel orientation a
