Ever since I got my DSA 815, I have noticed a little discontinuity in the full span trace right at 900 MHz. I also see it on other folk's YouTube videos, so I am pretty sure it is not some fault unique to me. Curiosity got the better of me, so I zoomed in on it and it looks funny
. Well, not that kind of funny...
The first pic is the full span with the little jog at 900 MHz (I did not realize at the time that it is at EXACTLY 900 MHz).
The second pic is zoomed in to a span of 100 Hz, a RBW of 10 Hz and a VBW of 1 Hz. I also turned on video averaging. This is a really small spur (I captured this with a 50 ohm load on the input so I am pretyty sure it is internal) so I am not worried about it disturbing anything. The funny thing about it is the little 6.42 dB jump in amplitude at about 6 Hz from the peak. The jump is really vertical, so I think it must be as the result of something switching in or out.
Anyone have any ideas as to why this is not just a plain peak? Could it be at the point where a different filter or oscillator or something kicks in or out? Is this the kind of thing you would see on any SA, or is this a low end equipment kind of thing? (I love this thing, but I know it is not a $30,000 unit...)