Expansion board EXP3-SC adds RF over Fiber reception to MRK980 and MRK16 receivers. It replaces coax with optical fiber, enabling antenna placement at very long distances while preserving RF performance. The module covers 170–1260 MHz, uses 2 x BNC RF connectors and 2 x SC/APC optical connectors, and measures 20 × 94 × 146 mm (H × W × D) with a 130 g mass. It requires EXP0 on MRK980 (one per receiver) for installation.