Kenwood TS-820 Service Bulletins

Key Information and Troubleshooting

This collection of service bulletins addresses various operational issues and provides solutions for the Kenwood TS-820 and related models (TS-520/S, TS-820/S). It details specific problems encountered with transmitters and receivers, including low RF output, audio distortion, intermittent operation, and component failures.

Specific technical notes cover adjustments for the speech processor, carrier point, balance modulation, and RIT modification. Installation guides for features like the AUX band are also included.

Component and System Specifics

• Transmitter Issues: Covers problems such as low RF output, no transmit, audio quality issues, and component failures like bad transistors or resistors.
• Receiver Issues: Addresses low sensitivity, intermittent reception, noise, and audio problems, often pointing to specific components or wiring faults.
• Speech Processor Alignment: Provides detailed steps for aligning the speech processor for optimal performance, including adjustments for compression level and carrier balance.
• RIT Modification: Details a modification to improve the 'rubbery' tuning of the RIT (Receiver Incremental Tuning) control.
• Filter Switching: Offers guidance on implementing CW Wide/Narrow filter selection for TS-520S and TS-820/S series transceivers.
• Component Replacements: Includes information on replacing obsolete components, such as the TA7201P audio amplifier with a substitution kit.

General Alignment and Maintenance

The bulletins also provide simplified alignment procedures for various units, including the AVR Unit, VCO Unit, and Coil Pack, ensuring accurate frequency calibration across different bands.

Information is provided by TRIO-KENWOOD COMMUNICATIONS, INC., with addresses in Compton, California, and Gardena, California.