Kenwood TS-990S Service Manual

Also see for SP-990: Instruction manual

Contents

TS-990S55COMPONENTS DESCRIPTIONRef. No. Use/Function Operation/Condition/CompatibilityD32,33 RX 2nd mixer Recieving mixer (8.248MHz24kHz)D34~39 Surge absorption Relay (K11~K16)D40,41 Clipper FM demodulator IC inputD42,43 Switching FM wide/narrow switchingD44 Switching ON when 15kHz IF fi lter is se-lectedD45 Switching ON when 6kHz IF fi lter is se-lectedD46 Switching ON when 2.7kHz IF fi lter is se-lectedD47 Switching ON when 500Hz IF filter is select-edD48 Switching ON when 270Hz IF filter is select-edD49 Switching ON when additional IF fi lter isselectedD50 Surge absorption Relay (K17)D52, 53 Reverse currentprevention Control line of Q51D54, 55 Reverse currentprevention Control line of Q14D56,57 Switching ON when BPF of 35~40MHz isselectedD501~506 Surge absorption Relay (K501~K506)D507 Switching ON when BPF of 14.5~18.5MHzis selectedD508 Switching ON when BPF of 21.5~26.5MHzis selectedD509 Switching ON when BPF of 26.5~35MHz isselectedD510 Switching ON when BPF of 46.5~60MHz isselectedD511 Switching ON when BPF of 4.1~6MHz isselectedD512 Switching ON when BPF of 7.5~10.5MHz isselectedD513 Switching ON when BPF of 40~46.5MHz isselectedD514 Switching ON when BPF of 4.1~6MHz isselectedD515 Switching ON when BPF of 7.5~10.5MHz isselectedD516 Switching ON when BPF of 14.5~18.5MHzis selectedD517 Switching ON when BPF of 21.5~26.5MHzis selectedD518 Switching ON when BPF of 26.5~35MHz isselectedD519 Switching ON when BPF of 40~46.5MHz isselectedD520 Switching ON when BPF of 46.5~60MHz isselectedTX-RX UNIT (X57-827X-XX)Ref. No. Use/Function Operation/Condition/CompatibilityIC51 Shift registerQ1: SBPF[13] “H” when BPF of50M band is selected (TX only)Q2: SBPF[12] “H” when BPF of30~60M band is selectedQ3: SBPF[11] “H” when BPF of28M band is selectedQ4: SBPF[10] “H” when BPF of21M band is selectedQ5: SBPF[9] “H” when BPF of14M band is selectedQ6: SBPF[8] “H” when BPF of11M band is selectedQ7: SBPF[7] “H” when BPF of10M band is selectedQ8: SBPF[6] “H” when BPF of7M band is selectedIC52 Shift registerQ1: SBPF[5] “H” when BPF of5M band is selectedQ2: SBPF[4] “H” when BPF of3.5M band is selectedQ3: SBPF[3] "H" when BPF of1.8M band is selectedQ4: SBPF[2] “H” when BPF ofBC band (522k~1.705MHz) isselectedQ5: SBPF[1] “H” when BPF ofBC band (30~522kHz) is selectedQ6: S6DB “L” when sub RX 6dBor 18dB attenuator ONQ7: S12DB “L” when sub RX12dB or 18dB attenuator ONQ8: S455FIL “L” when 455kHzFM 9kHz (narrow) fi lter is se-lectedIC53 Shift registerQ1: SFIL[1] “H” when 15kHz IFfi lter is selectedQ2: SFIL[2] “H” when 6kHz IFfi lter is selectedQ3: SFIL[3] “H” when 2.7kHz IFfi lter is selectedQ4: SFIL[4] “H” when 500Hz IFfi lter is selectedQ5: SRXFM “H” when sub RXFM mode is selectedQ6: TXFM “H” when TX FMmode is selectedQ7: SHFRGC ReservedQ8: S50RGC ReservedIC54 Shift registerQ1: SPRE[1] “H” when subreceiving preamplifi er is ONQ2: SPRE[2] “H” when subreceiving 21.5~60MHz and pre-amplifi er is ONQ3: 1STIF “H” when sub RX 1stIF of 73.095MHz is selectedQ4: DRVO “H” when drive out-put is selectedQ5: AMC “H” when AM TX isselected (for 50msec)Q6: RLSW “H” when LINEAR is“H”