: Some users on radio forums have shared specific circuit modification diagrams , including guides for improving AM/LW reception. Core Internal Architecture
Given the specificity of your request and the emphasis on "extra quality," I will assume you're looking for a detailed overview or an enhanced version of the schematic for educational or personal project purposes.
is vague – schematics are either readable/accurate or not. High-resolution vector PDFs or clear photos of a traced PCB are rare for this radio.