Dallas STX 165 Instruction Manual

STX 165 Operation
TheSTX165isaModeCtranspondercapableoftransmitting4076differentcodesinresponsetogroundradarinterro-
gations. AlloperationsoftheSTX165arecontrolledthroughthefrontpanelcontrols. Thecontrolsareasfollows:
Power/ModeControl
VFRPushbutton
IdentPushbutton
SelectKnob
DataKnob
EnterPushbutton
ThePower/Mode
Control TheSTX 165 will comeon anytime power isapplied to the rearconnector. Itis recommended
thatpowertotheSTX165issuppliedthroughapanelmountedavionicsmasterswitch. TheSTX
165 can be turned off by pressing and holding the Power button for three seconds. It can be
turnedon againbymomentarilydepressing thePowerbutton.
ThePower button has two additionalfunctions. OneisasanEscapemode. If the operator is ina
programingmode and wishes toescapetothemainpage, he can pressthePowerbuttonmomen-
tarily. Thiswillcancelallprogrammingandshowhisnormaldisplaypage.
Thepowerpushbuttonisalsoused to start the counters. This is explained in the counter section.
SBY: TheSTX165isinstandbymodeandwillnotrespondto radar interrogations.
ON: TheSTX is on and respondingtoradarinterrogationsbutisnot reporting altitude.
Thisis often referred to asModeA
ALT: TheSTX165isresponding toradarinterrogations withaltitudeinformation.
Thisis often referred toas Mode C
DataKnob
EnterPushbutton Thesearedualconcentricknobswithapushbuttonaction. ThelargerSelect knobisa momentary switchthatisspringloaded. Itcanbeturnedclockwiseandcounterclockwiseandwillreturnto
centerwhenreleased. Itis used to move the cursor duringCode selectionand totoggle through
thedisplay options in the lowerleftdisplay(PALT,DALTandOAT). Note that DALTandOAT
areonly available if the optionalSandiaOATprobemodel STP78is installed.
Thesmaller innerknobisthe Data knobandisused toselectthedigitvalue whenprogramingthe
squawk code and to select the counter function in the lower right display when not in the cod
selectionmode.
TheData know can alsobe pressed to Enterdata after it hasbeen programmed.

VFRPushbutton TheVFRPushbuttonisuseto select the VFRSquawkcode. Pressingita second time willrecall
thepreviouscode.
TheVFRpushbuttonanadditionalfunction. Pressingandholdingitforthreesecondswillenlarge
thesquawkcode display. Wheninthismodethe functions on the bottomportion ofthedisplay
screenwillnolongerbedisplayed. PressingandholdingtheVFRPushbuttonforthreeseconds
againwillexitthismode. Thisfunctionisusefulinhighsunlightconditions,particularlywithbubble
canopies.
Whenpoweris first applied to theSTX165,theSANDIA aerospace logo will be displayedalong withtheunitversion
number(the lasttwodigits ofthepartnumber), theDisplaysoftware version(D)andthe Mainsoftwareversion (M). The
current software versions can be seenon the SANDIA aerospace web site at www.sandia.aero.
IDTPushbutton The IDTis the Indentpushbuttonand is depressedwhen requested byATC to Ident. TheSTX
165remainsintheIdentmodefor22.5seconds. Whentransmitting Ident,IDwill bedisplayedin
theleft portionofthedisplay.
2

Afterthesoftwareversionsaredisplayed, the STX 165 display will revert to the normal operating mode. The upper left
portionofthedisplay willshowthe currenttansmitterMode. Theupperrightportionofthedisplaywillshowthelast code
thatwasselectedprior to shut down, the PressureAltitude (PALT)isdisplayedinthelowerleftandElapsedFlightTime
(EFT)inthelowerrightofthedisplay. The built-inencoderrequiresawarm uptimeandthePALTvaluewillshow dashes
untilthe properinternaltemperatureis reached.
Theusercan set the mode to come on intheALTmodeatstartup or at a predetermined altitude differentialafter takeoff.
Thesame is true for theEFTdisplay. See UserSetUp for a discussion ofthesefeatures.
3
Code Selection
To select a new squawk code you will usethe Data/Select knoband pushbutton:
Pressthe Enter Pushbutton thefirstdigitinthe squawk codewillblink.
Rotatethe smaller Dataknobuntilthevalue ofthecodesfirstdigit is displayed.
Rotatethelarger Select knob clockwiseto thestopand then release. The second digitofthe squawk code will be
blinkingindicatingthatitcanbechanged.
Continuerepeatingtheabovestepsuntilyouhaveselectedthedesireds=codeandthenPresstheEnterPushbutton.
Thenew squawk codehasbeen selected andis now being reportedtoATC.
Note:Theselectknob is a spring load alternate action knob it can be turned
bothclockwise and counter clockwise and willthenreturntocenter.
Mode Selection
To select the Mode ofOperationyouwill use the ModeControl knob.
Rotatethe Mode Control knob toselectone of three transmitterModes.
SBY Standby. The STX165 ison but notresponding toATC interrogations
ON TheSTX165is on and replying in ModeA(NoAltitudeReporting)
ALT The STX 165 is on andreplyinginModeC(AltitudeReporting)

4
Altitude/Temperature Displays
Altitudeand temperature information is displayedinthelowerleftdisplayquadrant. The operator can cycle throughthe
differentinformationbyturning theSelectknb(thelargerightsideknob).
PressureAltitude TheSTX165hasabuilt-inTSO’daltitude encoder. Theoutputoftheencoderispressurealtitude
andis displayed a PALT. It canbedisplayedineitherfeetormeters depending on the user set up
configuration
DensityAltitude If anoptionalSANDIAaerospaceOATprobeisinstalledwiththeSTX165itwilldisplayDensitiy
Altitude, DALT. DALT is based on the current OAT and PressureAltitude. DALT will be
displayedin either feetormetersdepending on theusersetupconfiguration
OAT IfanoptionalSANDIAaerospaceSTP78OATprobeisinstalledwiththeSTX165,itwilldisplay
thecurrentOutsideAirTemperatureineitherdegreesFahrenheitofCelsiusdependingontheUser
SetUpselection.
IcingAlert Ifan optional SANDIAaerospace STP78OATprobeisinstalledwiththe STX165,itwilldisplay
anIcingAlertin the upper right hand corner ofthe displaywhen thetemperature reacheda user
defined temperature. The Snow Flake symbol will bling for ten second once the IcingAlert
temperatureis reached then remain on soliduntilthetemperaturegoesabovethe preset number.
PressureAltitude DensityAltitude OutsideAirTemperature IcingAlert
Timers
TheSTX165hasthreetimerfunctionsthataredisplayedinthelowerrighthandcornerofthedisplay. Theseare
ElapsedFlightTime (EFT),an up counter (CNTUO) and a downtimer (CNTDOWN). To select atimerrotate the
Dataknobeitherclockwiseorcounterclockwise.
ElapsedFlightTime WhentheSTX165is firstturnedon thetimerfunctionwillbeinitializedontheElapsedFlight
Time(EFT) page. The EFTwill begincountingatsystemturn on oratapredeterminedaltitude
setbythepilot in the User Set Up mode. TheEFTcanonlybereset by turning the unit off.

5
CounterUp
TheCounterUp(CNTUP)allowsthepilottotimevariousauxilaryfunctions. Itcanbeactivatedandresetatanytime.
TousetheCNTUpfunction:
1. RotatetheData Knob until CNT UP is displayed. It will initialize on 0.00S if has not been used since
systemstart up.
2. To startthe CNTUp,press the Power/Modecontrolpushbutton.
3. Press the Power/Modecontrolpushbuttonagain andthetimerwill discontinuecounting,andhold the
elapsedtime.
3. To startanew timer function press, thePower/Mode control. TheCNTUPwillresettozero and begin
countingup.
CounterUp
CounterDown
Thecounterdown(CNT DOWN) allows the pilot to entera specifictime andthen bealerted whenthattimehas
expired. Thistimer is especiallyusefullfortimedapproached. When activated, thedowntimewillcount down tozero
andthen begin counting up. During thecountingupphase,thetimewill be preceded by aplussymbol(+).
1. Rotatethe Data Knobuntilthe CNTDOWNlegend is displayed. You will notethatthe CNTDOWN
timedefault isoneminuteandzero seconds.
2. Toprogram a new time, pressandhold the Data knob forthreeseconds. The second will begin to
blink.
3. Turn the Data knob to enterthe newtime. Note thatyou canprogram secondsand minutesform the
secondspositon as the time roolsoverwhenever you reach 60seconds. You can also rotatetheSelect
knobto theminutespositionifdesired.
CounterDown

User Configuration
Whilewe obviously can’tbeallthingstoall people, theSTX165allowsthe user to selectcertainparametersthathe may
find use full. It is recommended the user only change these configurations when on the ground. This will keep from
interferingwith hispilotdutiesand ensureuninterruptedresponsetoATCradar interrogations.
1. To enterthe User Set UPmodetheSTX 165 mustbe in theSBY(Standby)mode.
2. Press and hold the IDT pushbutton while turning and holding the Select knob for 3 seconds (Note that the select
knobwillgoto ahardstopwhenrotated approximatelyaneighthofaturn). Thedisplaywill read“USERSETUP
MODE. PRESS ENTER TO CONTINUE.
3. PresstheEnterpushbutton. NotethatiftheEnterPushbuttonisnotpressed within ten second the STX 165 will
exitthesetup mode.
Note: The STX 165 must be in SBY mode to enter the User Set Up
Function.
Thefirstpage displayed when enteringtheuserSet Up mode isTEMPUNIT. Toaccess subsequent set up pages,
rotatethe Data knob.
TEMPUNIT The STX165willdisplaytemperatureineither degrees Fahrenheit ordegreesCelsius. The
factorydefaultsettingisFehrenheit. Toselectadifferenttemperatureunit:
WhileontheTEMPUNITpagerotate the Select knob counterclockwise to select Celsius and
clockwiseto selectFahrenheit.
ALTUNIT TheSTX can displayaltitude ineither metersor feet. Thecatory defaultis feet. Toselecta
differntaltitudevalue,.
1. Select theALTUNITpage.
2. Rotate the Data knbCounterclockwiseto select Meters andClockwiseto select Feet.
6

MODE-CALT The STX 165 is designed to turn on in the Standby (SBY) Mode. The user can
selectanaltitude at which the STX165willautomatically select Mode-C (ALT)
Mode. Thisaltitudeis the differential altitude fromwhentheSTX 165 was first
turnedon. ToselectanAuto On altitude:
1. Rotate the Data knob to select theAUTO MODE CALT page.
2. Pressthe EnterPushbutton. TheAutoAltOnaltitudewill beblinking.
3. Rotate the Dataknob to select thedesiredAuto OnAltitude. The
altitudewill changein25foot or10meterincrements.
4. Press the Enter Pushbutton
Note:TheAutoOnAltitudeis thedifferentialAltitudefromwhenthe
STX165 is turned on. Forexample if theAuto On altitudeis set for
200 feet and the STX 165 is turned on at 1200 feet, the STX 165 will
automatically selectALT Mode at 1350 feet.
EFTSTART
ALT
Note: If 0 (zero) feet or meters is selected inAUTO MODE CALT,
theSTX 165 willturn on intheALTMode. This isgenerally not
recommended. IfOFF isselected, thepilot willbe requiredto select
the ON orALT Mode.
TheSTX 165startswith theEFTdisplayedinthelower righthandcorner ofthedisplay. Theuser
cansettheEFTto begin counting at turn on or at a specifiedAlt above the turn on altitude. It the
EFTis set at 0, then the EFTwillbegincountingatturnon. To set the EFTstart altitude:
1. Rotate the Dataknob to select theEFTSTARTALTpage.
2. PresstheEnterPushbutton. The EFT startaltitudewillbe blinking.
3. RotatetheDataknobtoselectthedesiredAuto OnAltitude. The altitude will change in
25footor10 meter increments.
4. Press the Enter Pushbutton
AUTO
ICINGALERT IfaSANDIAAerospaceSTP78OATprobeisinstalledwiththe STX165theunit willprovidean
icing alert. The icing alert is a snow flake that appears in the upper right corner of the display
wheneverauserpresettemperatureis reached. To set the IcingAlerttemperature:
1. Rotate the Dataknob to select theICINGALERTpage.
2. PresstheEnterPushbutton. The bracketswillextinguishandtheTemperature willblink
3. Rotate the DataknobuntilthedesireIcingAlerttemperatureisdisplayed.
4. Press the Enter Pushbutton.
7

MIN
BRIGHTNESS TheSTX165’sdigitaldisplayautomaticallyadjuststoambientlightconditions. Theminimum
intensityto whichtheSTX 165willadjustis setbytheuser. Tosettheminimum intensity:
1. Rotate the Dataknob to select theMIN BRIGHTNESS page.
2. PresstheEnterPushbutton. Thebracketswillextinguishindicating theMinBrightness
canbe adjusted.
3. Rotate the Dataknobclockwisetoincrease the minimum brightnessandcounterclock-
wisetodecreasetheminimumbrightness.
4. Press the Enter pushbutton to select the new setting.
DefaultVFR The STX 165 comes preset with 1200 as the VFR squawk code. In some instance a different
codeis desirable fortheVFR squawk. To change theVFR squawk code:
1. Rotate the Dataknob to select theDEFAULTVFR page.
2. PresstheEnterknob. Thebracketswillextinguishandthefirstdigitofthesquawk
codewill beblink,indicating itcanbeprogrammed.
3. Rotate the Data knobtoselect the first digit ofthedesiredsquawk code.
4. RotatetheSelect knob. Thefirstdigitwillgosolidandtheseconddigitwillblink
indicationit canbechanged.
5. Continue as above unit all digits are change to the desired code.
6. PresstheEnter Pushbutton. Theblinkingwillstopand the bracketswillreturn
indicatingthe code has been selected
Note:It isthe pilot’s responsibilityto insurethat thepropersquawk
code is selected.
8