LNB REF signal (TCXO inside the LNB & Ref fed by the duplex) has an effect on the output signal.
Recently, I measured and compared the spectrum of the output signal of LNB using different REF modes.
First measure the TCXO installed inside the LNB.The signal looks clean.Low base noise, good signal-to-noise ratio
The measurement then provides a REF signal to the LNB through a diplexer.
The output signal becomes very noisy.The signal-to-noise ratio is significantly lower.Has anyone done the same measurement?
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