The service manual for the Kenwood TKR-720 and TKR-820 desktop repeaters provides detailed instructions for setup, operation, and troubleshooting, including information on field programming, power output adjustments, and modular design for optimal performance in various environments. It also covers the use of Quiet Talk (QT) and Digital Quiet Talk (DQT) signaling systems, ensuring reliable communication in both urban and rural settings, and includes specifications for receiver and transmitter performance, as well as options for DC auto-revert and duplexer installation.
Manual Overview
The Kenwood TKR-720(N)/820(N) service manual provides detailed instructions for technicians on troubleshooting, diagnostics, and maintenance of these VHF/UHF desktop repeaters. The manual emphasizes the modular design, which isolates receiver and transmitter sections for enhanced reliability and shielding. For troubleshooting, the manual includes flowcharts and diagnostic procedures to identify and resolve common issues. Error codes and diagnostics are provided to assist in pinpointing faults within the system. Calibration and adjustments are crucial for optimal performance; the manual outlines procedures for setting RF power output, which is adjustable from 2 to 25 watts for UHF and 15 to 50 watts for VHF. Board-level guidance is offered for components such as the RX VCO, TX VCO, MIC AMP, and other critical units, with detailed circuit descriptions and block diagrams. The manual also covers the installation of optional features like the DC auto-revert circuit and duplexer kits, ensuring technicians can maintain and upgrade the repeaters effectively.
Quick Issues Covered
- Diagnose power-up failures with detailed troubleshooting steps.
- Calibrate RF power output for optimal performance in various settings.
- Use schematics for effective circuit tracing and component identification.
Overview
The Kenwood TKR-720(N)/820(N) is a VHF/UHF desktop repeater designed for small to medium-sized applications, providing reliable performance with adjustable power output. It features a high-performance receiver suitable for urban, suburban, and rural areas, and includes Quiet Talk (QT) and Digital Quiet Talk (DQT) signaling systems. The repeater is compact, with a die-cast chassis and large heatsink for durability, and offers modular design for maximum reliability. It is easy to program and reconfigure, with options for AC and DC power.
Specifications
- Frequency range Type 1: 150 – 174 MHz
- Frequency range Type 2: 136 – 150 MHz
- Frequency range Type 3: 490 – 512 MHz
- Frequency range Type 4: 406 – 430 MHz
- Number of channels: 7
- Channel spacing: 12.5 kHz
- Input voltage: AC 50/60 Hz (Modifiable to DC back-up)
- Power Consumption: 230 watts maximum
- Duty cycle: 50% at 50 watts output (100% at 15 watts output)
- Operating temperature range: -30°C to +60°C
- Dimensions (W x H x D): 4-3/4 x 13 x 15 in. (120 x 330 x 383 mm)
- Weight (net): 28.65 lbs (13 kg)
- FCC ID Type 1: ALH TKR-720N-1
- FCC ID Type 2: ALH TKR-720N-2
- FCC ID Type 3: ALH TKR-820N-3
- FCC ID Type 4: ALH TKR-820N-4
- RF input impedance: 50 ohms
- Sensitivity EIA 12 dB SINAD: 0.35 µV
- 20 dB quieting: 0.45 µV
- Squelch sensitivity: 0.2 µV threshold
- Modulation acceptance: ±3.5 kHz
- Selectivity: 80 dB
- Intermodulation distortion: 75 dB
- Spurious & image rejection: 90 dB
- Frequency stability: ±0.00025% (-30°C to +60°C)
- Audio output: 4 W (at 4 ohms, less than 5% distortion)
- RF power output: 50 watts adjustable to 15 watts (duplexer input)
- RF output impedance: 50 ohms
- Spurious & harmonics: -80 dB
- Modulation: F3E ±2.5 kHz for 100% at 1000 Hz
- FM noise: 40 dB
- Microphone impedance: Low impedance
- Audio distortion: Less than 3% at 1000 Hz
- Signaling: Maximum number of tones: 8
- QT decoder/encoder: Decoder/encoder tone frequency: 67.0 to 210.7 Hz (in 0.1 Hz steps)
- Decoder response time: 200 msec. or less
- Squelch tail elimination time: 100 msec
- Encoder frequency error: 0.05% or less
- Sensitivity SINAD: 8 dB or less
- DQT decoder/encoder: Data code: 23 bits total; a 3-digit octal number (0-7, 12 bits) with error correction (11 bits)
- Decoder response time: 250 msec. or less
- Turn-off code transmission time: 196 msec
- Sensitivity: SINAD 8 dB or less
- Time-out timer: Adjustable OFF, 30 sec. – 5 min.
- Hang timer: Adjustable 0 – 5 sec.
Controls & Indicators
The source does not provide specific information about the front-panel controls or indicators for the TKR-720(N)/820(N) VHF/UHF Desktop Repeater.
Installation / Setup
The Kenwood TKR-720(N)/820(N) VHF/UHF Desktop Repeater is designed for easy setup and reliable performance. It features adjustable RF power output, which can be configured for low power in small industrial plants or high power to cover larger areas. The modular design separates the receiver and transmitter sections for optimal shielding and reliability. The compact desktop design allows for flexible placement without the need for special environmental controls. The system is field programmable and utilizes advanced synthesized RF technology for flexibility and reliability. The die-cast chassis and large heatsink provide protection and enable long operating hours. Optional DC auto-revert feature ensures continued operation during power outages.
Operation
Refer to the PDF for details.
Troubleshooting & Error Codes
Refer to the PDF for details.
Safety & Warnings
Refer to the PDF for details.
Download MANUAL Service manual (PDF – 22.2 MB)
Kenwood TKR-720/820 Service Manual PDF (22.2 MB) for troubleshooting, calibrating, and servicing communication equipment.
- Brand: Kenwood-tkr-720-tkr-820-service
- Model: MANUAL
- Type: Service manual
- File size: 22.2 MB
Overview
Brief overview of the product.
Specifications
- Key spec 1
- Key spec 2
Controls & Indicators
Control panel/button layout.
Installation / Setup
- Step 1…
- Step 2…
Operation
Basic usage, modes, cycles.
Troubleshooting & Error Codes
| Issue / Code | Fix |
|---|---|
| Example | How to fix… |
Safety & Warnings
- Important warning…
Downloads
Download MANUAL service manual (PDF)
Kenwood TKR-720 / TKR-820 Service Manual Overview
The Kenwood TKR-720 and TKR-820 are professional-grade two-way radio repeater systems designed to extend communication range in commercial, industrial, and public safety environments. These repeaters receive and retransmit radio signals, ensuring clear and reliable communication over large areas and challenging terrains. The service manual provides detailed instructions for installation, maintenance, troubleshooting, and repair of these models.
Main Features and Specifications
- Frequency Range: VHF and UHF bands depending on model
- Power Output: Up to 50 watts for extended coverage
- Channel Capacity: Supports multiple programmable channels
- Advanced Signal Processing for noise reduction and clarity
- Durable metal chassis designed for rugged environments
- Built-in diagnostics and fault detection systems
- Compatible with a wide range of Kenwood accessories and control stations
Basic Usage and Operation Tips
To operate the Kenwood TKR-720/820 repeater effectively, ensure it is installed in a well-ventilated area to prevent overheating. Use the service manual to program channels and set power levels according to your communication needs. Regularly verify antenna connections and alignment for optimal signal transmission. Always perform a system test after installation or maintenance to confirm proper operation.
Troubleshooting and Maintenance Notes
Common issues include signal interference, power supply faults, and overheating. Refer to the manual’s troubleshooting section to identify LED status indicators and error codes. Regularly clean cooling fans and vents to maintain airflow. Inspect internal components for signs of wear or damage during scheduled maintenance. Replace any faulty parts with genuine Kenwood components to ensure reliability.
Safety Reminder
Always disconnect the repeater from power sources before performing any maintenance or repairs. Avoid exposing the unit to moisture or extreme temperatures. Use appropriate personal protective equipment when handling electronic components. Follow all safety guidelines outlined in the manual to prevent injury and equipment damage.