Don't forget that the 70 cm receiver also has an internal reference oscillator than can be selected, at least in this current version. The phase noise of both oscillators need to be considered.
On 6/11/07, Matt Ettus [email protected] wrote:
Robert McGwier wrote:
Thank you all for this great conversation. I want to remind everyone that we need long term coherence in the receiver, which can only be accomplished by low phase noise, not for the purity of the tone needed to be heard by a human ear, but by the need to correlate for long known symbols to recover frequency and timing in the SMS text messaging system and to do COHERENT detection of the symbols transmitted. We want the analog transponder to support this. This is also contributes to the requirement for a much larger dynamic range in the system than we have had heretofore on our spacecraft.
This will be completely controlled by the master reference oscillator. Are there specs for this? Is someone designing one?