The Calsense Spread Spectrum Frequency Filter, model SR-FILTER, is an optional bandpass filter used to help prevent interference from unwanted frequencies by filtering them out. The resonators and cavities within the filter are silver plated for low RF resistivity, in order to achieve low insertion loss and high selectivity. It may be required when using SR‐STICK or SR‐YAGI antennas.

Spread Spectrum Filter Specifications


  • Height: 1.89”
  • Width: 4.72”
  • Depth: 2.36”


  • Bulkhead

Wireless Interface

  • Frequency Range: 902 – 928-MHz
  • Interference Rejection: > 45-dB
  • Insertion Loss: 1.5-dB


  • Operating Temperature: -45° to 85°C (-49° to 185°F)


  • 1-year limited warranty