Operation Manual

Page 64
FT
DX
3000 OperaTing Manual
TheAutomaticAntennaTuner(hereinafterreferredtoasthe“ATU”)builtintoeach
FT
DX
3000
isdesignedtoensurea
50-Ohmloadforthenalamplierstageofthetransmitter.WerecommendthattheATUbeusedwheneveryouoperate
onthe
FT
DX
3000
.
Advice:

 BecausetheATUofthe
FT
DX
3000
islocatedinsidethestation,itonlyadjuststheimpedancepresentedtothetrans-
ceiveratthestationendofyourcoaxialcablefeedline.Itdoesnot“tune”theSWRattheantennafeedpointitself.
Whendesigningandbuildingyourantennasystem,werecommendthateveryeffortbemadetoensurealowSWR
attheantennafeedpoint.

 TheATUofthe
FT
DX
3000
includes100memoriesfortuningdata.Elevenofthesememoriesareallocated,oneper
Amateurband,sothateachbandhasatleastonesettingpresetforuseonthatband.Theremaining89memoriesare
reservedforthe89most-recenttuningpoints,forquickfrequencychangewithouttheneedtoretunetheATU.

 TheATU in the
FT
DX
3000
 is designed to matchimpedances within the rangeof 16.5 Ohms to 150 Ohms, cor-
respondingtoanSWRof3:1orlessonthe160through6meteramateurbands.Accordingly,simplenon-resonant
whipantennas,alongwithrandom-lengthwiresandthe“G5RV”antenna(onmostbands)maynotbewithintheim-
pedancematchingrangeoftheATU.
ATU OperATiOn
uSing The auTOMaTic anTenna Tuner
1. Use the MainTuning Dial knob to set the radio to
thedesiredoperating frequency withintheAmateur
band.
2. Press the
[
TUNE
]
 button momentarily toplace the
ATUinthetransmitline(no adjustment/tuningwill
occur yet).The “
TUNER
” icon will appear in the
display.
QUick pOinT:
 Themomentarypressofthe
[
TUNE
]
buttonwillturn
thetuneron, and themicroprocessor will automati-
cally select the tuning point closest to the current
operatingfrequency.
3. Pressandholdinthe
[
TUNE
]
buttonforonesecond
tobeginautomatictuning.Thetransmitterwillbeen-
gaged,andthe“
TUNER
”iconwillblinkwhiletun-
ing is in progress.When the optimum tuningpoint
has been reached,the radio will return toreceive,
andthe“
TUNER
”iconwillagainglowsteadily(in-
steadofblinking).
4. TodisconnecttheATUfromthetransmitline,press
the
[
TUNE
]
 button momentarily.The “
TUNER
”
iconwillturnoff,conrmingthattheATUhasbeen
turnedoff.Inthe“Off”mode,thetransceiverwillbe
directlyconnectedtothecoaxialcableconnectedto
your antenna, and will respond to whatever imped-
anceispresentatthestationendofthecoax.
Advice:
TheATUcircuit is located between the nal amplier
andtherear-panelantennajack;receptionisnotaffected
bytheATU.
QUick pOinTs:
As shipped from the factory, only oneATU alignment
pointissavedoneachAmateurband.Thiswas memo-
rizedduringthenalalignmentandperformanceveri-
cationstagesontheproductionline.
nOTe:
Please check the operating frequency before beginning
the tuning process, to be sure you are notinterfering
withotherswhomayalreadybeusingthefrequency.
TerminOlOgy:
Antenna Tuner Memories: Themicroprocessor of the
ATUmakesanoteoftheselectedtuningcapacitorsand
inductors,and storesthedataforeach10kHzwindow
inwhichtuning hasoccurred.Thiseliminatestheneed
tore-tuneeverytimeyoureturntoafrequencyonwhich
youhavealreadycompletedthetuningprocess.
[
TUNE
]
Button