Yaesu FT-991 Operating Manual

Also see for FT-991: Manual Manual Operating manual Reference book Instruction manual

Contents

Page 141FT-991 O PERA T I N G M A N U A Linstallation of optional accessoriesA ctive-tuning A ntennA SySteM (AtAS-120A) operAtionATAS-120A is a multi-band auto-tuning antenna that can be used in the amateur bands from the HF band to the UHFband (7/14/21/28(29) /50/144/430)Using the active tuning mechanism, tuning can be carried out automatically by the control signal from FT-991. Pleaserefer to the ATAS-120A Operating Manual for the assembly and installation of ATAS-120A.Interconnections to FT-991Connect “ATAS-120A” to the ANT terminal of FT-991 with a coaxial cable as shown in the diagram below.A dvice :r Turn off the external power supply switch and theFT-991 power supply switch first before connectingthe cables.r Grounding is required for the ATAS-120A. Makesure the antenna base is in contact with the car bodyto ensure proper grounding.note:r Do not plug or unplug the connector of the antennacable with wet hands. Do not plug or unplug theconnector during transmission as well. This mayresult in electric shock, injury, etc.r The unit cannot be used with both the antenna tunerand ATAS-120A connected.ATAS-120ADedicated V/UHF band antennaFT-991CommercialantennaduplexerCommercialantenna baseFT-991ATAS-120AATAS-120A connection exampleWhen installing a dedicated VHF/UHF antenna si-multaneously with the ATAS-120A, use a VHF/UHFantenna that does not include the HF - 50 MHz bands(144/430 MHz type).The reception circuit of the V/UHF band may be im-pacted by the transmitter energy from the ATAS-120A.In addition, install the 2 antennas as far away from eachother as possible.When using an antenna duplexer, the ANT terminal ofthe ATAS-120A and the HF/50 MHz ANT terminalof the FT-991 must be connected in series and alsoinsulated from the grounding in order to supply thecontrol voltage for the ATAS-120A.