Mais um Sharp BX-338: um defeito raro quase condenou este rádio

In this video, I present the restoration of another classic Sharp BX-338 radio, a model that caught my attention for its excellent aesthetic condition, but which hid some unexpected challenges. After complete disassembly, all metal components underwent a recovery process with citric acid, ultrasonic cleaning, and neutralization, while the cabinet and switches received cleaning and preventive maintenance. In the electronics, a complete recap was performed, out-of-specification carbon resistors were replaced, and a broken trace causing a difficult-to-locate intermittent signal was repaired. The biggest challenge, however, was the variable capacitor. Even after several cleaning attempts, the radio continued to lose tuning due to a hidden mechanical defect. Investigation revealed a fracture in the rear bearing of the variable capacitor shaft, compromising the rotor's electrical contact and causing the local oscillator to fail during tuning. The solution involved rebuilding this support, allowing the recovery of a component that, at first glance, seemed doomed. Finally, a complete recalibration of the receiver was performed, including adjustment of the local oscillator and dial, restoring the BX-338 to its excellent sensitivity and the pleasant sound characteristic of Sharp germanium transistor radios. If you enjoy restoring vintage radios, analog electronics, and diagnosing real-world faults, subscribe to the channel and follow our upcoming projects. New videos on restoration, electronic instrumentation, and diagnostic techniques applied to classic equipment are released every week. @Maxayantiguidades @Museudaeletronica @shango066