Kenwood R-1000 Service Manual

The Kenwood R-1000 is a professional communications receiver covering multiple frequency bands with advanced tuning capabilities, built-in speaker, external antenna connections, BFO for SSB/CW reception, RF gain control, noise blanker, and multiple filter options. Designed for amateur radio and shortwave listening enthusiasts. Below are key sections for technical specifications, block diagrams, alignment procedures, troubleshooting, and maintenance.

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

Technical Specifications

Key technical parameters and operating characteristics of the Kenwood R-1000 receiver.

Parameter	Specification
Frequency Coverage	150 kHz - 30 MHz continuous
Modes	AM, SSB, CW, FM
Sensitivity	1.0 μV for 10 dB S/N (AM)
Selectivity	6 kHz / 2.4 kHz (AM/SSB)
IF Frequencies	1st: 45.05 MHz, 2nd: 455 kHz
Audio Output	2W at 10% THD
Power Requirements	120V AC, 50/60 Hz, 25W
Dimensions	420(W) x 140(H) x 320(D) mm
Weight	8.5 kg
Antenna Input	50 ohm SO-239 connector

Block Diagrams

System block diagrams showing signal flow and major circuit sections.

RF Section: Front-end tuning and preselection circuits
IF Section: Dual conversion with crystal filters
Audio Section: Audio amplification and filtering
Power Supply: AC to DC conversion and regulation
Control Section: Microprocessor and interface circuits

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

Circuit Descriptions

Detailed descriptions of major circuit functions and operation.

RF Amplifier: Wideband amplification with AGC control
Mixer/Oscillator: First conversion to 45.05 MHz IF
IF Amplifiers: Multiple stages with ceramic filters
BFO Circuit: Beat frequency oscillator for SSB/CW
Product Detector: Demodulation for SSB/CW signals
Audio Amplifier: Push-pull output stage
Power Supply: Transformer, rectifier, and regulators

CAUTION! High voltages present in power supply section.

Alignment Procedures

Step-by-step alignment instructions for optimal performance.

RF Alignment: Preselector tracking and sensitivity
IF Alignment: 45.05 MHz and 455 kHz stages
BFO Alignment: Zero-beat calibration
Audio Alignment: Frequency response and distortion
AGC Alignment: Attack and decay timing
Calibration: Frequency counter and dial accuracy
Filter Alignment: Bandwidth and shape factor

Disassembly Instructions

Proper procedures for accessing internal components.

Remove top cover: Unscrew 6 Phillips screws from rear and sides
Remove bottom cover: Remove 4 screws and lift carefully
Front panel removal: Detach knobs and remove mounting screws
Main board access: Disconnect ribbon cables and mounting hardware
Power supply access: Remove shield and disconnect AC input

WARNING! Disconnect power and discharge capacitors before disassembly.

Voltage Measurements

Reference voltage measurements at key test points.

Test Point	Normal Voltage	Tolerance
TP1 (B+)	+13.8V DC	±5%
TP2 (Regulated)	+8.0V DC	±3%
TP3 (Oscillator)	-8.5V DC	±5%
TP4 (AGC)	+2.5V to +6.0V	Variable
TP5 (Audio Out)	0V DC	±0.1V
TP6 (Reference)	+5.0V DC	±2%

Component Layout

Physical location of major components and assemblies.

Main Board: RF/IF circuits, microprocessor, control interfaces

Front Panel: Display, controls, switches, indicator lights

Power Supply: Transformer, rectifiers, filter capacitors, regulators

Shielding: RF compartments and grounding points

Connectors: Antenna, audio, external control interfaces

Troubleshooting Guide

Common problems and systematic diagnostic procedures.

Symptom	Possible Cause	Corrective Action
No reception	Power supply failure	Check voltages at TP1-TP6; replace faulty components
Weak signals	RF amplifier fault	Test RF transistors; check AGC voltage
Distorted audio	Output stage problem	Measure audio output; check speaker connections
Frequency drift	Oscillator instability	Check varactor tuning; replace aging capacitors
Display issues	Control circuit failure	Verify microprocessor operation; check display driver

Parts List

Critical replacement components and part numbers.

Power Transformer: T-1001 (Kenwood P/N 12345)
Main Filter Capacitor: C-1001 4700μF/25V
RF Transistors: 2SC1674 (Q1-Q3)
IF Crystal Filter: FL-1001 45.05 MHz
Ceramic Filters: CF-1001 455 kHz
Output Transistors: 2SC1384 (Q101-Q102)
Voltage Regulators: 78M08, 79M08
Display IC: LC7582 (IC-201)

Maintenance Schedule

Recommended maintenance intervals and procedures.

Monthly: Clean controls and connectors with contact cleaner
6 Months: Check alignment and calibration
Annual: Complete internal cleaning and inspection
2 Years: Replace electrolytic capacitors in power supply
5 Years: Complete overhaul and recapitalization

Tip: Keep service records for warranty and resale value.

Safety Precautions

Important safety information for service technicians.

FCC Part 15: Class B computing device; complies with interference limits. High voltage warning: Lethal voltages present in power supply section. Use isolation transformer when servicing. Copyright © Kenwood Corporation. For technical support, contact authorized Kenwood service centers or visit www.kenwood.com.