What frequency does a C-Band LNB use?
A C-Band LNB receives satellite downlink signals in the 3.4-4.2 GHz range and downconverts them using a local oscillator, most commonly 5150 MHz for standard C-band. This produces an L-band output of roughly 950-1750 MHz for the receiver. C-band is prized for its resistance to rain fade, making it common for large dishes and reliable regional/DTH distribution.
The exact downlink range can vary by region and system: standard C-band covers 3.7-4.2 GHz, while extended C-band reaches down to 3.4 GHz. With a 5150 MHz local oscillator, the LNB subtracts the incoming frequency from the LO (or vice versa) to land in the L-band IF window.
Because C-band uses lower frequencies with longer wavelengths, it penetrates heavy rain and atmospheric moisture far better than Ku or Ka band. The trade-off is that C-band requires larger dishes (often 1.8 m and up) to gather enough signal, which is why it is favored for professional headends, cable feeds, and areas with intense tropical rainfall.