Codar_T-28_Manual操作说明书手册

TOP QUALITY一LOW COSTAMATEUR RADIO EQUIPMENT居T可/AA.F.GAINR.F.PEAKBANDCODAR T28METRESCODAR T28 2 BAND RECEIVERGENERAL INFORMATION AND SERVICE DATAThe CODAR T28 2 AMATEUR BAND 160-80 meter receiver employs 9 transistors plus1 diode.It is suitable for use from a 12 volt dry battery supply and can be safely usedfor mobile work where the battery voltage at times may be 14-15 volts.The R.F.stage is separately tuned by the PEAK control to assist in obtaining maximumperformance with the narrow band width and low impedances met with low frequencyloaded mobile aerial systems.A separate BFO is fitted and used in the conventional manner for the reception ofCw and SSB signals.On exceptionally strong SSB signals it may be necessarytoslightly detune the PEAK ocntrol to reduce signal input to obtain correct resolution withthe BFO.The peaking position of this control will depend largely on the aerial system in use.Withsome aerials it may be quite sharp and others fairly broad.In home installations wherelong aerials may be in use,it is recommended that if necessary,the signal input be reducedby using a small series aerial capacitor.This may n.t be necessary if an aerial tuner unitis being used with the aerial system.For home or portable use,suitable dry batteries are three 44 volt type Vidor V8 or EverReady 126 connected in series which will give many months of service.Smaller typebatteries such as the Vidor VTl or Ever Readv PPl 6 volt (two in series)are alsosuitable for shorter term use.The receiver can function down to 9/10 volts but withlower gain and outputWARNINGCare must be taken that correct polarity of supply voltage be observed,otherwise thetransistors will be damaged.The RED lead is positive supply,and the BLACK leadnegative,also the receiver must not be switched on without the loudspeaker connected.The R.F.Transistor can be damaged if no aerial input switching/muting is employed whenused with a transmitter.