SkyView - Dynon Avionics

Altitude Encoder CalibrationSV-XPNDR-26X Installation, Configuration, and TestingIn most transponder systems, a calibration is normally carried out every 24 months, as part ofthe altimeter checks on the aircraft. The maximum allowed difference between the primaryaltimeter and the altitude encoder is 125 feet in ETSO C88a and TSO C88b. The primaryaltimeter in SkyView and the altitude encoder are one and the same device. It is thereforeimpossible for the encoder and the primary altimeter to exceed 125 feet of altitude difference.They will always be exactly the same as each other, thereby meeting the TSO requirements.Therefore, no altitude encoder calibration is possible or necessary.At times it may be useful to know the altitude that is being reported to the transponder. SinceSkyView sends pressure altitude to the SV-XPNDR-26X, setting BARO to 29.92 will display thepressure altitude being transmitted to the transponder in the normal SkyView altitude displayon the right side of the PFD page.However, do note that there is a single point altitude adjustment, located in SETUP MENU >HARDWARE CALIBRATION > ADAHRS CALIBRATION > ALTITUDE ADJUST that adjusts SkyView’sbarometric altimeter. This adjustment affects both the displayed altitude and the encodedaltitude that is sent to other devices.Post Installation ChecksPost installation checks should be carried out in accordance with your certificationrequirements. These checks should include:Mode S interrogations to verify correct address programming.Verification of the reported altitude using a static tester.Where installed, verification of correct squat switch ground/airborne indications. In anaircraft with a squat switch, setting the Mode switch to ALT when the aircraft is on theground should leave the transponder in GND mode; when the aircraft becomesairborne, the mode should switch automatically to ALT.Interrogations to verify the receiver sensitivity. A Mode S transponder should have aminimum triggering level (MTL) of between -77 dBm and -71 dBm. Failure to meet thisrequirement usually indicates antenna or coaxial cable problems.Interrogations to verify the transmitted power. A Class 1 installation should have no lessthan 125 Watts at the antenna (and no more than 500 Watts). A Class 2 installationshould have no less than 71 Watts at the antenna (and no more than 500 Watts).Failure to meet this requirement is also generally due to antenna or wiring issues.Where installed, verification of the GPS position source and ADS-B outputs. Whenever avalid position is received by the transponder and the transponder is in any mode otherthan Standby, ADS-B Extended Squitters should be observed on the transponder testset.Ensure all regulatory requirements are met. In the United States, the transponder mustSkyView System Installation Guide - Revision J 11-15