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<blockquote data-quote="s-band" data-source="post: 1111792" data-attributes="member: 407744">It may be related to higher phase noise on the Norsat. [USER=175005]@John[/USER] had a&nbsp; band A with water ingress on which the synth had been damaged. That was an extreme example as the phase noise was awful. The signal levels were fine but very little would demodulate. The narrower the signal, the more sensitive it will be to poor phase noise.Here's an example where I was using an external reference with a Gilat but the reference phase noise was not fantastic. The phase noise increases with frequency multiplication by 20 log10 (N) dB where N is multiplication factor. I changed the divider to increase the ref frequency and reduce the multiplication (from 64 to 16) and improved it significantly. The CS plots show the effect of the higher phase noise spreading the constellation. You need a strong, low symbol rate, signal to check in this way.Of course, your problem may be something completely different!</blockquote>

[QUOTE="s-band, post: 1111792, member: 407744"] It may be related to higher phase noise on the Norsat. [USER=175005]@John[/USER] had a band A with water ingress on which the synth had been damaged. That was an extreme example as the phase noise was awful. The signal levels were fine but very little would demodulate. The narrower the signal, the more sensitive it will be to poor phase noise. Here's an example where I was using an external reference with a Gilat but the reference phase noise was not fantastic. The phase noise increases with frequency multiplication by 20 log10 (N) dB where N is multiplication factor. I changed the divider to increase the ref frequency and reduce the multiplication (from 64 to 16) and improved it significantly. The CS plots show the effect of the higher phase noise spreading the constellation. You need a strong, low symbol rate, signal to check in this way. Of course, your problem may be something completely different! [/QUOTE]

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