Kenwood TS-990S Service Manual

Also see for SP-990: Instruction manual

Contents

TS-990S56COMPONENTS DESCRIPTIONRef. No. Use/Function Operation/Condition/CompatibilityIC54 Shift registerQ7: LINEAR “H” when con-trolled linear relay is selectedQ8: TCS “L” when during ATtuningIC55 D/A convertorAo1: ReservedAo2: SIFGC Sub RX IF gaincontrol voltageAo3: ALCREF ALC referencevoltageAo4: TGC TX band gain controlvoltageAo5: POC TX power controlvoltageAo6: PGC TX power gain con-trol voltageAo7: PRO SWR protectioncontrol voltageAo8: SNBL/IDP Sub NB levelcontrol voltage on during subreceptionFinal circuit current protection onduring transmissionIC101 OP amplifi erA/2: Sub RX S-meter voltageamplifi erB/2: Main RX S-meter voltageamplifi erIC481 OP amplifi er A/2: No usedB/2: SAGCV voltage amplifi erIC601 OP amplifi er A/2: Sub RX 3rd IF amplifi erB/2: No usedIC602 Sub RX FM IC Sub RX FM demodulatorIC603 OP amplifi erA/2: Sub RX FM noise squelchvoltage amplifi erB/2: Sub RX FM AF signal ampli-fi erIC604 Multiplexer Sub receiver output, FM (AF) andSSB/AM/CW (IF) changeoverIC701 TX mixer Transmission mixer(24kHz>10.695MHz)IC702 TX mixer Transmission mixer(73.095MHz>HF)IC801~803 OP amplifi er ALC protectionIC804 OP amplifi er Amplifi er for meterQ102 Switching External sub squelch outputsignal (open collector)Q103 Mute For main ANO muteQ104 Buffer Buffer amplifi er for main ANOoutputQ105 Mute For sub ANO muteQ106 Buffer Buffer amplifi er for sub ANOoutputQ107 Switching External main squelch outputsignal (open collector)Q108 Buffer Buffer amplifi er for PKS inputsignalQ109 Switching ON when relay for HF band linearis usedRef. No. Use/Function Operation/Condition/CompatibilityQ110 Switching ON when relay for HF band linearis transmissionQ111 Switching ON when relay for HF band linearis usedQ171,172 Switching ON when relay for HF band linearis usedQ201 SwitchingSub RX 6dBATT changeoverrelay (K201) control (OFF whensub RX 6dB and 18dB ATT areON)Q202 SwitchingSub RX 12dBATT changeoverrelay (K202) control (OFF whensub RX 12dB and 18dB ATT areON)Q203 Sub RX MuteMutes reception path duringtransmission (ON during trans-mission)Q204,205 Switching ON when BPF of30kHz~1.705MHz is selectedQ206 Switching ON when BPF of522kHz~1.705MHz is selectedQ207 Switching ON when BPF of 30~522kHz isselectedQ208 Switching ON when BPF of 1.705~2.5MHzis selectedQ209 Switching ON when BPF of 2.5~4.1MHz isselectedQ210 Switching ON when BPF of 4.1~6.9MHz isselectedQ211 Switching ON when BPF of 6.9~7.5MHz isselectedQ212 Switching ON when BPF of 7.5~10.5MHz isselectedQ213 Switching ON when BPF of 10.5~13.9MHzis selectedQ214 Switching ON when BPF of 13.9~14.5MHzis selectedQ215 Switching ON when BPF of 14.5~21.5MHzis selectedQ216 Switching ON when BPF of 21.5~30MHz isselectedQ217 Switching ON when BPF of 30~60MHz isselectedQ218 Switching ON when BPF of 49~54MHz isselected (TX only)Q219 Amplifi er Sub RX preamplifi er (~21.5MHz:12dB, 21.5~60MHz: 20dB)Q220 SwitchingSub RX preamplifi er gain control(ON sub receiving at21.5~60MHz)Q351~354 Sub RX 1st mixer Sub receiving 1st mixer(HF>11.374MHz)Q355,356 Amplifi er Sub RX SLO1 amplifi er (Sub RX1st IF of 11.374MHz is selected)