Kenwood TS-480HX Service Manual

The Kenwood TS-480HX is a high-performance HF/50MHz transceiver featuring 200W output power, advanced DSP technology, dual VFOs, built-in automatic antenna tuner, multiple operating modes including SSB, CW, AM, FM, and digital modes. This service manual provides comprehensive technical information for maintenance, repair, and service procedures. Below are key sections covering specifications, block diagrams, alignment procedures, troubleshooting, and parts lists.

1. Technical Specifications 2. Block Diagrams 3. Circuit Descriptions 4. Alignment Procedures 5. Disassembly Instructions 6. Troubleshooting Guide 7. Parts List 8. PCB Layouts 9. Wiring Diagrams 10. Test Equipment Requirements 11. Service Notes

Technical Specifications

Complete technical specifications for the Kenwood TS-480HX transceiver system.

Parameter	Specification
Frequency Range	1.8-30 MHz (HF), 50-54 MHz (6m)
Output Power	200W PEP (HF), 100W PEP (50MHz)
Modes	SSB, CW, AM, FM, Digital (PSK31, RTTY)
Receiver Sensitivity	0.16 µV for 10 dB S+N/N (SSB)
Power Supply	13.8V DC ±15% (negative ground)
Current Drain	Receive: 1.3A, Transmit: 22A max
Dimensions	240(W) × 85(H) × 260(D) mm
Weight	3.2 kg (main unit)
Antenna Impedance	50 ohms unbalanced
Built-in Tuner	Automatic, 16-150 ohms

Block Diagrams

System block diagrams showing signal flow and major circuit sections.

RF Unit Block Diagram: Shows receiver front-end and transmitter final stages
IF Unit Block Diagram: DSP processing and intermediate frequency circuits
Control Unit Block Diagram: Microprocessor and interface circuits
Power Supply Block Diagram: Voltage regulation and distribution
Antenna Tuner Block Diagram: Automatic matching network

WARNING! High voltages present in power amplifier section. Use extreme caution when servicing.

Circuit Descriptions

Detailed descriptions of major circuit functions and operation.

Receiver Circuit: RF amplifier, mixer, IF stages, and detector circuits
Transmitter Circuit: Microphone amp, modulator, driver, and PA stages
DSP Circuit: Digital Signal Processing for filtering and noise reduction
Control Circuit: Microprocessor system and user interface
Power Supply Circuit: DC-DC converter and voltage regulators

CAUTION! Static sensitive components. Use proper ESD protection.

Alignment Procedures

Receiver Alignment: RF sensitivity, IF alignment, AGC timing
Transmitter Alignment: Carrier suppression, sideband balance, power output
VCO Alignment: PLL lock range and stability
Filter Alignment: Crystal and ceramic filter adjustments
DSP Alignment: Digital filter settings and noise blanker
Meter Calibration: S-meter and power meter calibration
Tuner Alignment: SWR detection and matching network
Test Equipment: Spectrum analyzer, oscilloscope, power meter required

Disassembly Instructions

Step-by-step disassembly procedures for service access.

Front Panel: Remove knobs, front bezel screws, carefully separate control board

Main Unit: Remove bottom cover, shield plates, and module retaining screws

Circuit Boards: RF unit, control unit, display board, power supply board

Mechanical Parts: Fan assembly, heat sink, final transistor module

Troubleshooting Guide

Systematic troubleshooting procedures for common problems.

Symptom	Possible Cause	Corrective Action
No power	Power supply, fuse, cable	Check DC input, replace fuse F1 (15A), verify cable connection
No transmit	PA circuit, relay, control	Check final transistors Q12-Q15, measure driver stages
Poor reception	RF amp, mixer, antenna	Verify antenna connection, check Q1-Q3 in RF unit
Display issues	Display board, connections	Check flat cable CN1, measure display voltages
Tuner not working	Motor, sensors, control	Check tuner motor operation, verify SWR detection

Reset: Hold [F] and [LOCK] while powering on for factory reset.

Parts List

Complete parts list with component designators and specifications.

Semiconductors: Transistors, ICs, diodes with part numbers
Passive Components: Resistors, capacitors, inductors values
Mechanical Parts: Screws, brackets, knobs, connectors
PCB Assemblies: Complete board part numbers
Optional Parts: Accessories and replacement kits

Tip: Use genuine Kenwood parts for optimal performance and reliability.

PCB Layouts

Printed circuit board layouts for all major assemblies.

Supports maintenance and component-level repair of circuit boards.

Main Board: Component placement and trace routing
RF Board: High frequency layout considerations
Control Board: Microprocessor and interface circuits
Display Board: LCD and backlight circuitry
Power Supply Board: DC-DC converter layout

WARNING! Observe proper grounding and shield placement during reassembly.

Wiring Diagrams

Complete wiring and interconnection diagrams.

Test Equipment Requirements

Essential test equipment for proper service and alignment.

DC Power Supply: 13.8V, 30A capacity with current limiting
RF Power Meter: 1-200W range, 1.8-54MHz frequency
Oscilloscope: Dual trace, 50MHz bandwidth minimum
Frequency Counter: High accuracy for frequency verification
Dummy Load: 50 ohm, 200W power rating
Signal Generator: RF coverage 1.8-54MHz
Multimeter: Digital with high impedance input
Spectrum Analyzer: For advanced troubleshooting (recommended)

Service Notes

Important service notes and technical updates.

FCC ID: K663810

Service bulletins, firmware updates, and modification notes. For technical support, contact Kenwood authorized service centers or visit www.kenwood.com. Copyright © Kenwood Corporation. All rights reserved.