PRO-23-(Operating-Guide操作说明书手册)

PR0-23(200-0104)OperationAfter batteries,crystal(s)and antenna (telescopic or flexible)havebeen installed,your PRO-23 is ready to use.Turn power on by turning VOLUME to the right.Turn SQUELCH to theminimumposition to the far left.Set all the channel lock-out switches inthe upposition,toward the LED indicators.You should hear a rushing soundfromthe speaker.Turn SQUELCH to the right until the background noise abruptly stops.You can't adjust SQUELCH properly while listening to a station,sowaitsignals cease.If you set SQUELCH correctly,the PRO-23 will appear"dead"until a signal comes in;when a signal comes in,the Squelchcircuit will "open up"and you'1l hear the signal.When the signalceases,the Squelch circuit will "close"and cut out all sound untilthe next signal comes in.If you want the PRO-23 to scan the channels continuously for thecrystalsyou have installed,adjust SQUELCH as previously instructed,then setthe SCAN/MANUAL switch to the SCAN position.The PRO-23 willconstantlyscan each channel in sequence;when a signal appears on one of thechannels the receiver will lock onto that channel and you will hearthesignalIf you do not want automatic scanning on one or more channels,pushtheappropriate Channel Lock-Out Switch(es)down,or away from the LEDindicator.If you want to stay tuned to one channel only,set the SCAN/MANUALswitchto the MANUAL position (stop scanning)and then press MANUALmomentarilyto advance to the channel you want to listen to (as indicated by theLEDabove that channel switch).For MANUAL scanning,the receiver can beeither "squelched"(adjusted as previously indicated)or"unsquelched"(the SQUELCH control set to extreme left).For automatic scanning,SQUELCH must be set to eliminate the background noiseMAXIMUM SENSITIVITY RANGEThis Receiver will function adequately down to 118 and up to 136 andfrom144 to 174 MHz,but with reduced sensitivity at the upper and lowerextremes.For maximum sensitivity on the VHF-Aircraft band thechannelfrequencies you choose should be within +/-3 MHz of 127 MHz (that is,in