Garmin AT SL-70 Mode C Transponder User Manual Operation manual

Garmin AT, Inc. Mode C Transponder Operation manual

Contents

Operation manual

Using Altitude HoldAltitude Hold helps you maintain a constant altitude. The current pressurealtitude is stored as a reference and is the displayed value unless Altitude Holdis activated. The hold altitude is displayed in 100-foot increments. Thedisplayed altitude is the same as is sent for Mode C interrogation replies.When the HLD button is pressed, the altitude display will be set to “+000.”The altitude display values will increase/decrease as the aircraft changesaltitude. The altitude display will flash when the aircraft change in altitudeexceeds the selected threshold.Setting the Hold Altitude1. Press the HLD button to set the current altitude as the hold altitude. TheLED above the HLD button will light to indicate Altitude Hold is active.2. The Altitude display now shows a value that is relative to the hold altitudein 100-foot increments. A displayed value of +001 means you are 100 ftabove the hold altitude.Setting the Altitude Hold Buffer1. Set the Altitude Hold Buffer value by pressing the HLD button for twoseconds, or longer. Select a value between 200 and 2500 feet. The factorydefault value is 300 feet. The value is retained when the SL70 is turned off.2. Turn the SMALL knob to change the buffer value, such as ±02. Press HLDagain to save the value.DisplaysSquawk CodesThe four-digit squawk code is shown on the left side of the display.AltitudeThe Altitude display is used to show the pressure altitude, Hold Altitude, andHold Altitude buffer with 100 ft resolution.© 1999 by UPS Aviation Technologies, Inc. All rights reserved. Printed in theU.S.A.UPS Aviation Technologies, Inc.2345 Turner Road, S.E. Salem, OR 97302U.S.A. Toll Free 800.525.6726Canada Toll Free 800.654.3415International 503.391.3411FAX 503.364.2138Visit our web page at http://www.upsat.comApollo®Mode C TransponderModel SL70Operation Manual
August 1999 560-0401-00Apollo SL70The Apollo SL70 Mode C Transponder complements the Apollo SL series ofslimline avionics. The SL70 provides Mode A/C functionality certified toTSO-C74c Class 2A meeting VFR and IFR requirements, operates on 10-35VDC, includes squawk code display and selection, standby, altitude, and identoperation. All of these features are contained in the space-saving 1.3”H x6.25”W form factor, with bright easy-to-read LED characters, and user-friendly operation. A photocell on the front of the SL70 adjusts the LEDintensity for ambient light conditions. The SL70 will automatically test itsreceive function if no interrogations have been received in the last 30 seconds.KnobsA single knob on the left side controls power on/off. Rotate the knobclockwise to turn transponder power on. Rotate the knob counterclockwise toturn power off.Dual concentric knobs on the right side are used to select squawk codes andchange altitude values. Turning the large, outer knob moves the cursor toallow editing of the selected character. Turning the small, inner knob changesvalues.PushbuttonsPress the pushbutton once to activate the selected operation. An LED aboveeach pushbutton will light when that button is pressed.IDENTPress the IDENT button once to reply with an identifying squawk code, Identmode. In Ident mode, the Reply LED will be lighted for 20 seconds. TheReply (Ident) LED will also flash when the SL70 generates transponderreplies.SBYPress SBY to place the transponder in “Standby” mode. The SL70 is “on,” butno information will be transmitted.ONPress for Mode A operation. The SL70 is “on” and will transmit its squawkcode when interrogated.ALTPress for Mode C operation. The SL70 is “on” and will transmit its squawkcode and altitude when interrogated.VFRPress VFR once to set the VFR squawk code. Press VFR a second time totoggle between the VFR squawk code and the previously entered code.HLDPress to enable/disable altitude hold. The LED above the HLD button islighted when altitude hold is enabled.Selecting a Squawk CodeThe selected squawk code will always be in use. As you change a squawkcode, the original code will be sent until you are finished selecting the newcode. When changing a code, the display will stop flashing and selection isstopped if the controls are not used for three seconds or more. Pressing anypushbutton will also end code selection. The squawk code is automaticallyreset to the VFR code when the SL70 is turned back on.1. Rotate the LARGE knob clockwise one position. The first character of thesquawk code will flash.2. Rotate the SMALL knob to the desired number for the first digit.3. Rotate the LARGE knob to move the cursor to the next desired digit. Turnthe SMALL knob to select the desired number.4. Repeat step 3 for each of the desired digits.
5. After the last digit is selected, rotate the LARGE knob clockwise one moreposition. The display will stop flashing and the new code will be sent.Special Squawk CodesSpecial Squawk CodesSpecial Squawk CodesSpecial Squawk Codes1200 – Default VFR code in the USA.7500 - Hijacking7600 – Loss of communications7700 – EmergencySee the Airman’s Information Manual for more information about squawk codes.

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