22Basic OperationPreparationPrecautions When you use the FT1DR with the external power supply cable (E-DC-6) connected to an externalpower supply, pay attention to the following:• The power supply voltage must be 12 V to 14 V.If the voltage exceeds 14 V, the high voltage protection function is activated to disable high-powertransmission. L3 (2.5 W) is selected automatically to reduce the transmission power.If the voltage exceeds 16 V, failures such as damage to the electric circuits of the FT1DR canresult. Take extra care.• Connect the red/black wire or white/black wire of the external power supply cable (E-DC-6) to thepositive (+) terminal of the external power supply, and connect the black wire to the negative ()terminal.• Use an external power supply having sufficient current capacity (3 A or more).• If the supplied antenna remains installed, the external power supply can malfunction, resulting in afailure. If you use an external power supply, remove the supplied antenna and connect an externalantenna. Place the external power supply sufficiently away from the FT1DR. Use the FT1DR at the minimum required transmission power level to prevent overheating. Do not continue transmission for a prolonged period. The FT1DR can overheat, resulting in a failureor burn. If you operate the FT1DR for 7 hours or longer, it is recommended that you remove the battery packand install the optional battery case (FBA-39). Recharging the fully-charged battery pack repeatedly can shorten its life. Be extremely careful not todo so when you operate the FT1DR using an external power supply. While charging the battery pack, protect the FT1DR from splash of water. Charge the battery pack in a place where the ambient temperature is +5C to +35C. If the terminal or electrode of the battery case is dirty, the FT1DR can malfunction due to poorcontact, resulting in overheating or explosion. If the terminal or electrode gets dirty, clean it using adry cloth or cotton swab.Hints• The external power supply requires about 5 hours to charge the battery pack (about 8 hoursto charge the optional battery pack FNB-102LI). If the battery pack is charged with the FT1DRpowered, the charging time increases slightly.• The external power supply can be used with the battery case installed.In this case, “BATTERY NOT INSTALLED” is displayed on the LCD of the FT1DR; however, theFT1DR can be used, without any problem, with the battery case installed.• If you connect the FT1DR to the external power supply with it turned off, “CONNECTED TOEXTERNAL POWER” is displayed on the LCD, and about 20 seconds later “BATTERY NOTINSTALLED” is displayed.