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<blockquote data-quote="s-band" data-source="post: 1031748" data-attributes="member: 407744">[USER=402577]@tony smith[/USER] Interesting info. Whilst the dish is good to 30GHz, I am using a modified Gilat 19.2-20.2 LNB from an ODU so it droops a bit at the bottom end. I have bodged the Gilat feed directly on to it (It's wrong for the dish, f/d 0.6 not the 0.8 needed). That's losing something due to mismatch at the transition and probably over-illumination. In fact, it's a wonder it works at all! I get a total system noise figure (sky/ground measured) of 2dB at &gt;19GHz and 2.4dB at 18.6GHz. My LO is 18.25GHz. The TBS6983 can separate the lower 2 TPs which are 4MHz apart but here's a pic showing the spurious that blocks 18535:[ATTACH]111958[/ATTACH]I don't know why [USER=175007]@Llew[/USER] can't lock 18535 as the spacing is the same as the lower pair.&nbsp; I also note that 18557 is about 5-6dB down this morning compared to last night. I can only just lock it at times now.Edit at 10:50: 18515 is back just below threshold at 5.9dB</blockquote>

[QUOTE="s-band, post: 1031748, member: 407744"] [USER=402577]@tony smith[/USER] Interesting info. Whilst the dish is good to 30GHz, I am using a modified Gilat 19.2-20.2 LNB from an ODU so it droops a bit at the bottom end. I have bodged the Gilat feed directly on to it (It's wrong for the dish, f/d 0.6 not the 0.8 needed). That's losing something due to mismatch at the transition and probably over-illumination. In fact, it's a wonder it works at all! I get a total system noise figure (sky/ground measured) of 2dB at >19GHz and 2.4dB at 18.6GHz. My LO is 18.25GHz. The TBS6983 can separate the lower 2 TPs which are 4MHz apart but here's a pic showing the spurious that blocks 18535: [ATTACH]111958[/ATTACH] I don't know why [USER=175007]@Llew[/USER] can't lock 18535 as the spacing is the same as the lower pair. I also note that 18557 is about 5-6dB down this morning compared to last night. I can only just lock it at times now. Edit at 10:50: 18515 is back just below threshold at 5.9dB [/QUOTE]

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