Kenwood TS-990S Service Manual

Also see for SP-990: Instruction manual

Contents

TS-990S54COMPONENTS DESCRIPTIONRef. No. Use/Function Operation/Condition/CompatibilityQ55 Amplifi er MLO2 amplifi erQ56 Switching ON when 15kHz IF fi lter is se-lected (ON when MFIL1 is “H”)Q57 Switching ON when 6kHz IF fi lter is se-lected (ON when MFIL2 is “H”)Q58 Switching ON when 2.7kHz IF fi lter is se-lected (ON when MFIL3 is “H”)Q59 Switching ON when 500Hz IF filter is select-ed (ON when MFIL4 is “H”)Q60 Switching ON when 270Hz IF filter is select-ed (ON when MFIL5 is “H”)Q61 Switching ON when additional IF fi lter isselected (ON when MFIL6 is “H”)Q62 Switching ON when 500Hz IF filter is select-ed (ON when MFIL4 is “H”)Q63 Switching ON when 270Hz IF filter is select-ed (ON when MFIL5 is “H”)Q64 Switching ON when additional IF fi lter isselected (ON when MFIL6 is “H”)Q65 Switching ON when main FM narrow is se-lected (ON when M455FIL is “L”)Q66 Switching ON when 15kHz IF fi lter is se-lected (ON when MFIL1 is “H”)Q67 Switching ON when 6kHz IF fi lter is se-lected (ON when MFIL2 is “H”)Q68 Switching ON when 2.7kHz IF fi lter is se-lected (ON when MFIL3 is “H”)Q69 Switching ON when main FM wide is select-ed (ON when M455FIL is “H”)Q70 Amplifi er AGC ampliferQ71 SwitchingReceiver output, FM (AF) andSSB/AM/CW (IF) changeovermultipulexer (IC11) controlQ72 SwitchingATT switch for NB mode (ONwhen except NB mode (NBS is“L”))Q73 SwitchingNoise blanker changeover relay(K17) control (ON when NBS is“H”)Q74,75 Switching ON when MBPF14 is “H”, exceptMPRE1 or MPRE2 is “H”Q76 SwitchingON when BPF of 35~40MHz isselected (ON when MBPF14 is“H”)Q77 Switching Blanking switchQ501 Switching ON when BPF of 2.5~4.1MHz isselected (ON when MBPF4 is “H”)Q502 Switching ON when BPF of 6~7.5MHz isselected (ON when MBPF6 is “H”)Q503 SwitchingON when BPF of 10.5~14.5MHzis selected (ON when MBPF8 is“H”)Q504 SwitchingON when BPF of 18.5~21.5MHzis selected (ON when MBPF10 is“H”)Ref. No. Use/Function Operation/Condition/CompatibilityQ505 SwitchingON when any one of MBPF5, 7,9, 11, 12, 13, 14 is selected (ONwhen NRLY is “H”)Q506 SwitchingON when BPF of 1.705~2.5MHzis selected (ON when MBPF3 is“H”)Q507 Switching ON when BPF of 4.1~6MHz isselected (ON when MBPF5 is “H”)Q508 SwitchingON when BPF of 21.5~26.5MHzis selected (ON when MBPF11 is“H”)Q509 SwitchingON when BPF of 26.5~35MHz isselected (ON when MBPF12 is“H”)Q510 Switching ON when BPF of 7.5~10.5MHz isselected (ON when MBPF7 is “H”)Q511 SwitchingON when BPF of 40~46.5MHz isselected (ON when MBPF13 is“H”)Q512 SwitchingON when BPF of 46.5~60MHz isselected (ON when MBPF14 is“H”)Q513 SwitchingON when BPF of 14.5~18.5MHzis selected (ON when MBPF9 is“H”)D1 Surge protection Main reciever RF signal inputD2,3 Surge absorption Relay (K1/K2)D4,5 Surge absorption Internal circuit protectionD6 Switching6dB attenuator switch (ON whenMBPF14 is “H”, except MPRE1 orMPRE2 is “H”)D7,8 Surge absorption Internal circuit protectionD10,11 Surge absorption Relay (K3/K4)D12 Switching ON when BPF of 522k~1.705MHzis selectedD13 Switching ON when BPF of 30~522kHz isselectedD14 Switching ON when BPF of 522k~1.705MHzis selectedD15 Surge absorption Relay (K5)D16 Switching ON when BPF of 30~522kHz isselectedD17~20 Surge absorption Relay (K6~K9)D21 Detection Noise blanker switching pulsedetectionD22,23 Reverse currentprevention MBLNK control lineD24 Switching Select of MLO2 outputD25 Surge absorption Relay (K10)D26~29 Noise blanking(Mute) ON when MBLNK signal is “H”D30 Attenuator IF gain adjustmentD31 Switching Select of 2nd IF signal output