The Optonica ST-3636 is an all-analog FM-AM tuner introduced in 1978. It features 5 FM gangs and 3 AM gangs, providing wide and narrow bandwidth settings. The tuner has both fixed and variable output jacks as well as a built-in 400 Hz tape calibration tone. The device is part of Sharp's Optonica lineup, which was positioned as high-end equipment during its production period. While its circuitry includes a distinctive 'Opto-Lock' feature designed to enhance signal locking, this can limit performance under certain conditions, particularly in DXing scenarios. Reports indicate that while the ST-3636 performs well with strong signals, it may struggle in more challenging reception environments without modifications. Its design includes multiple stages for audio processing, involving several transistors and ceramic filters, aiming to deliver a quality listening experience.
