For the reception of wideband satellite television carriers, typically 27 MHz wide, the accuracy of the frequency of the LNB local oscillator need only be in the order of ±500 kHz, so low cost dielectric oscillators (DRO) may be used. For the reception of narrow bandwidth carriers or ones using advanced modulation techniques, such as 16-QAM, highly stable and low phase noise LNB local oscillators are required. These use an internal crystal oscillator or an external 10 MHz reference from the indoor unit and a phase-locked loop (PLL) oscillator.