八重洲Yaesu_FRB-757_user操作说明书手册

Downloaded by▣▣Amateur Radio DirectoryFRB-757 RELAY BOX FORCONTROLLING A LINEAR AMPLIFIERWITH THE FT-757GXThe FRB-757 incorporates a transistor switch and an extra heavyduty relay for controlling all types of linear amplifiers withoutendangering the delicate internal switching circuitry of theFT-757GX HF Transceiver.Full break-in (QSK)amplifiers thatrequire only 12 to 20 VDC at less than 300 mA,such as the Alpha78,can be connected directly to the FT-757GX via the BAND DATAOUT jack without using the FRB-757.However,many other amplifiersinclude T/R relays that require voltage in excess of 50V,and/orcurrent in excess of 300 mA,and these must not be connecteddirectly to the FT-757GX for T/R relay control.In such cases,or when the T/R relay requirements of the amplifier areunknown,connect the FRB-757 as shown in the diagram below.LINEAR SWITCHW OFFNON QSK LINEARSP-102PFT-757GXooooOO00O00○OOO①OOOOFP-757GXTELEPHONE LINERX PTTFR8-757LINEAR SWITCHNON QSK LINEAR口OFFT-757GXFP-757HDRX PTTFRB-757