Kenwood TS-950S Service Manual

Also see for TS-950S Digital: Instruction manual Instruction manual Instruction manual Instruction manual Service manual

TS-950S/SDCIRCUITDESCRIPTIONCONTROL UNIT(X53-3230-00) (V3)FILTER UNITae TS i)(X51-3060-XX) (A/3} cer eae iy. 7= “7CONTROL UNIT(X53-3230-00) (8/3)KeyingsignalviRive[17of —_—SW UNIT (A)(X%41-3080-00)(H/10)iF UNIT(X48-3060-00)AVR UNIT(X43-3070-01)20Fig.8ALC,powercontrolandprotectioncircuitifthepoweroutputcontrolisusedonlywhen ALCactionbegins,itsrange increasesasthepoweroutputislowered. Therefore,theswitchunit (A)(H/10)PWRVRhastwofunctions;onecontrolsALC,andthe otherchangesthesecondgate voltage (PCV)ofQ22{38SK131)ontheRFunit.Bychangingthegatevoltage, thedif-ferencebetweenthemaximumandminimumgainsisapproximately10dBtoprevent excessiveALCactionwhenthepoweroutputislow.ThegainisalsoreducedduringATtuning.WhentheATSsignal arrivesattheRFunit,PCVisgroundedatQ25 (DTC124EK)toeliminate the influenceofPWRVR, andthesecondgate voltageismadeconstant(nearlythesamevalueaswhenthePWRVRisMIN)+ Protection circuit1) SWR protectionWhenthe reflectedwavevoltage (VSR)fromthefilterunitisraisedbyload variationorATtuning,Q2(2SC2712)ofthe controlunitturneson,andthevolt-ageon theALCtimeconstantcircuitisdecreased.Thepoweroutputislowered by decreasingthedrivetoprotectthefinaltransistor.FOR SERVICE MANUALSCONTACT:MAURITRON TECHNICAL SERVICESwww. mauritron.co.ukTEL: 01844 - 351694FAX: 01844 - 352554