Introduction
This document is the official service manual for the Kenwood TM-255A/E, a 144MHz All Mode Transceiver. It provides comprehensive technical information necessary for the maintenance, repair, and understanding of the transceiver's internal circuitry and operation.
Key Contents
The manual details the following critical aspects of the TM-255A/E:
- Circuit Descriptions: In-depth explanations of the transceiver's various functional blocks, including frequency configuration, PLL circuits, receiver and transmitter configurations, and specific circuits like noise blankers and S-meters.
- Component Information: Lists of components, exploded views, and PC board layouts to aid in identification and replacement.
- Adjustment Procedures: Step-by-step instructions for calibrating and tuning the transceiver for optimal performance.
- Specifications: Technical data and performance characteristics of the TM-255A/E.
- Diagrams: Block diagrams, wiring diagrams, and signal flow diagrams to illustrate the internal workings.
Technical Overview
The Kenwood TM-255A/E operates in the 144MHz band, supporting various modes. This service manual delves into the electronic design, including the phase-locked loop (PLL) system for frequency generation, the single and triple conversion receiver architecture, and the transmitter's signal modulation and amplification stages. It is intended for qualified service technicians.
