The CTL-22 Control is a serial tune control unit that is used for tuning the Pro Line II radios. The CTL- 22 is used to tune the VHF-21/22 COM radios in the normal range of 118.00 through 135.975 MHz and also in an extended frequency range through 136.975 or 151.975 MHz, depending on the capabilities of the radio under control. The CTL-22 outputs serial data to tune the radio being controlled and receives serial data being returned from the radio. The CTL-22 scans operator controls and discrete inputs for frequency, mode data and operating configuration. The CTL-22 can be configured to accept serial tuning data supplied from an external system. The CTL-22 provides nonvolatile storage of preset frequencies besides the active and preselect frequencies that are displayed. The CTL-22 serves only as a display unit and a means for transmitting the tune data to the radio. The display also shows diagnostic data received from the radio and allows for mode selection. The CTL-22 Control has a four and one half digit display.

The CTL-22 is available in several different variations which include options between 28V and 5V lighting and a black or gray panel. The CTL-22 can be panel mounted from the front or rear. The CTL-22 is certified for use in piston or turbine, fixed or rotary wing aircraft. The CTL-22 is convection cooled with a 35,000 Ft max altitude.