Kenwood TS 690S Service Manual

The Kenwood TS 690S is a high-performance amateur radio transceiver covering multiple HF bands with SSB, CW, and AM modes. This service manual provides comprehensive technical information for maintenance, repair, and adjustment procedures. Below are key sections covering specifications, block diagrams, alignment procedures, circuit descriptions, troubleshooting, and parts lists.

1. Technical Specifications 2. Block Diagrams 3. Circuit Descriptions 4. Alignment Procedures 5. Disassembly Instructions 6. Voltage Measurements 7. Troubleshooting Guide 8. Parts List 9. Schematic Diagrams 10. Maintenance Schedule 11. Safety Precautions

Technical Specifications

Complete technical specifications for the Kenwood TS 690S transceiver.

ParameterSpecification
Frequency Coverage1.8-30 MHz (all amateur bands)
ModesSSB, CW, AM
Power Output100W PEP (SSB), 100W (CW), 40W (AM)
Receiver Sensitivity0.25μV for 10dB S+N/N
Selectivity2.4kHz (SSB), 500Hz (CW), 6kHz (AM)
Power Supply13.8V DC ±15%
Current DrainReceive: 1.5A, Transmit: 20A max
Dimensions280W × 95H × 260D mm
Weight5.2 kg
Impedance50 ohms

Block Diagrams

System block diagrams showing signal flow and major components.

  1. RF Section: Front-end filtering, RF amplifier, and mixer stages
  2. IF Section: Multiple conversion stages with crystal filters
  3. Audio Section: Audio amplification and filtering circuits
  4. Power Supply: Voltage regulation and distribution
  5. Control Section: Microprocessor and interface circuits

NOTE! Refer to schematic diagrams for detailed component-level information.

Circuit Descriptions

Detailed descriptions of major circuit sections and their operation.

  1. Receiver Circuits: RF input, mixer, IF amplification, detector
  2. Transmitter Circuits: Microphone amp, modulator, driver, PA stages
  3. VFO Circuits: Frequency synthesis and stability circuits
  4. Control Circuits: Microprocessor, display, and interface functions
  5. Power Supply Circuits: Regulation and protection circuits

CAUTION! High voltages present in power amplifier section.

Alignment Procedures

Step-by-step alignment procedures for optimal performance.

Disassembly Instructions

Proper disassembly sequence for service access.

  1. Remove top and bottom covers: Remove all screws from case
  2. Front panel removal: Disconnect control cables and connectors
  3. Main board access: Remove mounting screws and support brackets
  4. Power supply removal: Disconnect all power connectors
  5. Final assembly unit removal: Carefully lift complete assembly

WARNING! Handle circuit boards by edges to avoid static damage.

Voltage Measurements

Key voltage test points and expected values.

Test PointVoltage (DC)Condition
TP1 (VCC)+13.8VPower on
TP2 (REG5)+5.0V ±5%Receive mode
TP3 (REG8)+8.0V ±5%Receive mode
TP4 (PA Bias)+0.6VReceive mode
TP5 (RF Drive)+2.5V P-PTransmit, 100W out

Troubleshooting Guide

Common problems and solutions for the TS 690S.

SymptomPossible CauseCorrective Action
No powerPower supply, fuse, switchCheck F1 fuse (8A), power cable, switch contacts
No receive audioAudio stages, speakerCheck audio IC (IC5), speaker connection, volume control
Low power outputPA stages, drive levelAdjust drive level, check final transistors (Q12,Q13)
Frequency driftVFO stability, PLLCheck VFO components, PLL lock, reference oscillator
No transmitPTT circuit, relaysCheck PTT switch, K1/K2 relays, control voltage

Reset: Power cycle unit; check all connections.

Parts List

Critical replacement parts and components.

Schematic Diagrams

Complete schematic diagrams for all circuit sections.

  1. Main Receiver/Transmitter schematic
  2. Power Supply and Control schematic
  3. VFO and PLL schematic
  4. Front Panel and Display schematic
  5. Interconnection diagrams

NOTE! Schematics show component values and test points.

Maintenance Schedule

Recommended maintenance intervals and procedures.

Clean controls and contacts every 6 months. Check alignment annually. Verify power output and sensitivity every 2 years. Inspect cooling system and replace thermal compound as needed.

CAUTION! Disconnect power before performing any maintenance.

Safety Precautions

Important safety information for service personnel.

High voltages present in power supply and RF sections. Use insulated tools. Discharge capacitors before servicing. Follow ESD precautions. Ensure proper grounding. Use recommended test equipment only.

WARNING! RF exposure hazard during transmission.

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