There are some problems with building a tracking generator for the Ultra
LO output is possible through the CAL port using CONFIG/MORE/LO OUTPUT but the level is somewhat lower then with the tinySA basic. Not a big problem.
Having good isolation between the almost 1 GHz LO in the tracking generator and the IF of the tinySA Ultra will be VERY difficult. At 1 Ghz almost everything becomes transparent which will reduce the dynamic range
But the biggest complicating factor, in my view, is the tuning mechanism used in the Ultra. The frequency steps of the main LO are in the order of kHz which is not good enough when using a 200 Hz RBW. This is solved by tuning both the LO (for the coarse steps) and the IF frequency (for the fine steps). Furthermore the IF filters have some manufacturing tolerance and for optimal performance the IF frequency is at startup time optimized for IF filter. And then there are some situations where the IF is shifted to solve various problems in the architecture.
As there is currently no way to know for sure the frequency of the IF at every point of the sweep you can only use the widest RBW with a tracking generator which also causes a loss of dynamic range.
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Designer of the tinySA
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