6CONNECTIONS AND INSTALLATION21 Installing internal optionsD Opening the caseFollow the case and cover opening proceduresshown here when you want to install an option or ad-just a setting for non-Icom tuner control.➀ Remove the 9 screws from the rear panel, then re-move the rear frame and rear sealing.➁ Remove the transceiver case.➂ When reassembling the transceiver, check the fol-lowing points:➠ Internal fan and slits in the case are on the sameside.➠ Front sealing is mated correctly.➠ Rear sealing is attached in the proper orienta-tion.➠ Screws are tightened securely.D Installing an optional filter and alarm unitAfter opening the case as shown above, install thedesired option to the position as at right. These op-tions are available (or already built-in) for the followingversions:After installing the 2-tone alarm unit into a Generalversion, remove the plastic cover on the [ALARM]switch to use the switch.Version Marine GeneralFL-100CW/FSK NARROW FILTER optional optionalUT-952-TONE ALARM UNIT built-in optional Fuse replacementThe transceiver has 3 fuses to protect internal cir-cuitry, 2 fuses for the fuse holder on the rear paneland 1 for inside. If the transceiver stops functioning,check the fuses below.Rear frameRear sealingFront sealingSpace for UT-95Space for the FL-100.(Plug in here. Right orleft orientation is okay.)5 A30 A