Kenwood TS-990S Service Manual

Also see for SP-990: Instruction manual

Contents

TS-990S59COMPONENTS DESCRIPTIONRef. No. Use/Function Operation/Condition/CompatibilityD351,353,354 Switching ON when sub RX 1st IF of11.374MHz is selectedD401,403 Switching ON when sub RX 1st IF of73.095MHz is selectedD404 Switching Sub RX/TX changeover, ON dur-ing sub receptionD405,406 Sub RX/TX mixerSub receiving 2nd/Trans-mission mixer (Sub RX:73.095MHz>10.695MHz)(TX: 10.695MHz>73.095MHz)D407 Switching ON when sub RX 1st IF of73.095MHz is selectedD408 Switching1/2: Sub RX/TX changeover, onduring transmission2/2: Sub RX/TX changeover, onduring sub receptionD409 Switching ON when sub RX 1st IF of73.095MHz is selectedD410,411 Switching Sub RX/TX changeover, on dur-ing sub receptionD481~484 Noise Blanking ON when SBLNK signal is “H”D487 Switching ON when 15kHz IF fi lter is se-lectedD488 Switching ON when 10.695MHz 2.7kHz IFfi lter is selectedD489 Switching ON when 500Hz IF filter is select-edD490,491 Switching Sub RX/TX changeover, on dur-ing sub receptionD492 Switching ON when 10.695MHz 2.7kHz IFfi lter is selectedD493 Switching ON when 500Hz IF filter is select-edD494 Switching ON when 15kHz IF fi lter is se-lectedD495 Switching ON when 6kHz IF fi lter is se-lectedD496 Switching Sub RX/TX changeover, on dur-ing transmissionD501 Attenuator IF gain adjustmentD502 Switching1/2: ON when Sub RX FM modeis selected2/2: ON when Sub RX SSB, AMand CW mode are selectedD503 Switching ON when 11.374MHz 2.7kHz IFfi lter is selectedD504 Switching ON when 6kHz IF fi lter is se-lectedD505 Switching Sub RX/TX changeover, on dur-ing transmissionD506 Switching ON when 11.374MHz 2.7kHz IFfi lter is selectedRef. No. Use/Function Operation/Condition/CompatibilityD601,602 Sub RX Mixer Sub recieving 3rd mixer(10.695MHz/11.374MHz>24kHz)D603,604 Clipper FM demodulator IC inputD605,606 Switching1/2: ON when FM 455kHz 9kHzfi lter is selected2/2: ON when FM 455kHz 12kHzfi lter is selectedD607 Switching1/2: ON when Sub RX FM modeis selected2/2: ON when Sub RX SSB, AMand CW mode are selectedD701 Switching1/2: ON when TX SSB, AM andCW mode are selected2/2: ON when TX SSB, AM andCW mode are selectedD702 Reverse currentprevention ON when TX FM modeD703~705 Attenuator TGC control attenuatorD706 Switching Sub RX/TX changeover, on dur-ing transmissionD707 Attenuator PGC control attenuatorD708 Switching Sub RX/TX changeover, on dur-ing transmissionD709 Switching On when transmitting from30~522kHzD710 Switching On when transmitting over1.705MHzD711,712 Surge absorption Drive output terminalD713 Switching ON when drive output is selectedD714 Switching ON when ANT connector is se-lectedD715 Switching Sub RX/TX changeover, on dur-ing transmissionD716 Switching ON during transmissionD717,718 Switching Sub RX/TX changeover, on dur-ing transmissionD801,802 Reverse currentprevention External ALC voltageD803 Current protec-tion Reduce power at over currentD804 Surge protection ALC meter voltageD805 Reverse currentprevention CKY signal lineD808,809 Reverse currentprevention Meter circuitD881 Detection Noise blanker switching pulsedetectionD882,883 Reverse currentpreventionSIBK and NB mute signal match-ing, sub RX mute when ON