The Kenwood TS-140S is a high-performance HF transceiver covering 1.8-30 MHz with 100W output power, featuring built-in antenna tuner, DSP filtering, multiple operating modes (SSB, CW, AM, FM), digital VFO, memory channels, and comprehensive receiver/transmitter specifications. This service manual provides technical information for maintenance, repair, and adjustment procedures.
Complete technical specifications for the Kenwood TS-140S HF transceiver system.
| Parameter | Specification |
|---|---|
| Frequency Coverage | 1.8-30 MHz (all amateur bands) |
| Output Power | 100W PEP (SSB), 100W (CW), 40W (AM) |
| Receiver System | Double conversion superheterodyne |
| Intermediate Frequencies | 1st IF: 69.0115 MHz, 2nd IF: 455 kHz |
| Sensitivity | SSB/CW: 0.25μV for 10dB S/N |
| Selectivity | SSB: 2.4kHz, CW: 500Hz, AM: 6kHz |
| Power Supply | 13.8V DC ±15% (negative ground) |
| Current Consumption | Receive: 1.3A, Transmit: 22A max |
| Dimensions | 240(W) × 85(H) × 260(D) mm |
| Weight | 4.2 kg |
System block diagrams showing signal flow and major circuit sections.
NOTE: Refer to schematic diagrams for detailed circuit connections.
Detailed descriptions of major circuit sections and their operation.
WARNING! High voltage present in final amplifier section.
Step-by-step alignment procedures for optimal performance.
CAUTION! Use proper test equipment and follow procedures exactly.
Systematic troubleshooting procedures for common problems.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| No power | Power supply fault | Check DC input, fuses F1/F2, regulator Q34 |
| No receive | Receiver section fault | Check RF amp Q1, first mixer Q2, PLL lock |
| No transmit | Transmitter section fault | Check driver Q16, final Q17, PTT circuit |
| Frequency error | PLL problem | Check reference oscillator X1, VCO tuning |
| Poor sensitivity | RF/IF alignment | Align receiver front end and IF stages |
Reset: Power cycle and check all connections.
Complete parts list with component designations and specifications.
NOTE: Use only Kenwood genuine parts for replacement.
Printed circuit board layouts and component location diagrams.
Tip: Use magnifying glass for small component identification.
Mechanical assembly and disassembly procedures.
WARNING! Handle final transistors with care to avoid damage.
Recommended test equipment for service and alignment.
| Equipment | Specification |
|---|---|
| RF Signal Generator | 1-30 MHz coverage, calibrated output |
| Oscilloscope | Dual trace, 50 MHz bandwidth |
| Power Meter | 100W capacity, 1-30 MHz |
| Frequency Counter | High stability, 10 Hz resolution |
| Dummy Load | 50 ohm, 100W continuous |
| DC Power Supply | 13.8V, 25A capacity |
Important service notes and technical updates.
Factory service bulletins, common failure modes, modification notes, and firmware updates. Includes information on DSP filter optimization and PLL stability improvements.
CAUTION! Observe static discharge precautions when handling ICs.
Complete schematic diagrams for all circuit sections.
Service: Authorized Kenwood service centers only.