Yaesu FT-847 Operating Manual

Also see for FT-847: Technical supplement Technical supplement Technical supplement Modification

Contents

29FT-847 OPERATING MANUALRear Panel Connectors(8) STBY JackThis 5-pin mini-DIN connector provides “closure-to-ground” switching lines for T/R control of externalamplifiers. One connection is provided for HF opera-tion, and one each for the 50, 144, and 430 MHz bands.The maximum ratings for these connections are +24VDC at 100 mA (only positive DC voltages are accept-able).(9) SP JackThis 3.5 mm, 2-pin miniature phone jack provides re-ceiver audio output for an external speaker. The audiooutput impedance is 4Ω ~ 16Ω, and the level variesaccording to the setting of the front panel’s AF (GAIN)control.(10) EXT PTT JackThis “RCA” female connector is used for connectionto a footswitch or other external switch for TX/RX com-mand control of the transceiver. This jack is wired inparallel with the front panel’s MOX switch; shortingthis jack to ground causes the transceiver to be placedin the Transmit mode, while opening the connectionto this jack returns the transceiver to the Receive mode.Open-circuit voltage is +5V DC, and closed-circuitcurrent is 1 mA.Note: This jack is designed to be used for externalPTT input only. Do not attempt to use the PTTjack for switching of amplifiers or other exter-nal devices (use the STBY jack for controllingsuch devices).(11) EXT ALC JackThis “RCA” female connector may be used to a linearamplifier’s ALC (Automatic Level Control) connec-tor, to prevent over-drive by the transceiver. The speci-fied control voltage range is 0V ~ −4V DC, with −4Vcorresponding to the maximum degree of power re-duction being applied to the transceiver.(12) 144 MHz Coaxial JackThis Type “M” (SO-239) jack is for connection of yourantenna for the 144 MHz band.(13) HF Coaxial JackThis Type “M” (SO-239) jack is for connection of yourantenna for the 1.8 ~ 29.7 MHz bands.(14) 50 MHz Coaxial JackThis Type “M” (SO-239) jack is for connection of yourantenna for the 50 MHz band.(15) 430 MHz Coaxial JackThis Type “N” jack is for connection of your antennafor the 430 MHz band. Do not, under any circum-stances, attempt to connect a Type “M” (PL-259) plugto this jack!