Yaesu FTDX101D User Manual

56
Using the Automatic Antenna Tuner
The Automatic Antenna Tuner (ATU) is built into each FTDX101 series. The ATU is designed to ensure
thata50-Ohmantennaimpedanceloadispresentedtothenalamplierstageofthetransmitter.
• Because the FTDX101 ATU is located inside transceiver, it can only adjust the impedance presented to the
transceiverendofthe coaxialcablefeedline.Itdoesnot“tune”theSWRattheantennafeedpointitself.
Whendesigningandbuildinganantennasystem,werecommendthateverye󰀨ortbemadetoalsoensurea
lowSWRattheantennafeedpoint.
• TheATUintheFTDX101isdesignedtomatchimpedanceswithintherangeof16.5Ohmsto150Ohms,
correspondingtoanSWRof3:1orlessontheHFamateurbands(6mamateurband:25Ohmsto 100
Ohms,correspondingtoanSWRof2:1orless).Accordingly,simplenon-resonantwhipantennas,alongwith
random-lengthwiresandthe“G5RV”antenna(onmostbands)maynotbewithintheimpedancematching
rangeoftheATU.
• Thebuilt-inantennatunercannotbeusedwithanantennaconnectorconnectedtoanexternalantennatun-
er(page102).
• ATU Operation
1. Press the [TUNE] key momentarily to place
the ATU in the transmit line (no adjustment or
tuningwilloccuryet).
WhiletheATUfunctionisactivated,theLED
insidethe[TUNE]keyglowsorange.
●Themomentarypressofthe[TUNE]key
willturnthetunerON,andthemicroproces-
sorwillautomaticallyselectthetuningpoint
closesttothecurrentoperatingfrequency.
2. Press and hold the [TUNE] key to begin auto-
matic tuning.
●Thetransmitterwillbeengaged,andthe
LEDinside[TUNE]keywillblinkwhiletun-
ing is in progress.
●Alwayslistenontheoperatingfrequency
beforebeginningthetuningprocess,tobe
suretuningwillnotinterferewithotherswho
mayalreadybeusingthefrequency.
●Whentheoptimumtuningpointhasbeen
achieved,thetransceiverwillreturntore-
ceive,andtheLEDinsidethe[TUNER]key
willagainglowsteadily(insteadofblinking).
3. TodisengagetheATUfromthetransmitline,
press the [TUNE] key momentarily.
The ATU microprocessor memories store the
recordofthecapacitorsandinductorsselected
totuneeach10kHzwindowinwhichtuning
has occurred. This eliminates the need to re-
tuneeverytimeoperationreturnstoafrequency
onwhichthetuningprocesshasalreadybeen
completed.

Yaesu FTDX101D Specifications

General

Brand	Yaesu
Model	FTDX101D
Category	Transceiver
Language	English