For me, it is nothing short of magic to create a 1Hz bandwidth RBW filter using crystals before the introduction of digital IF.
Up to this point, i have not paid much attention to crystals as they fall into the territories of the QRP homebrewers who want to make their own narrow bandwidth CW or SSB filters. I haven't got time to play with the measurement of crystal parameters, ladder filter, Dishal design programme, crystal matching and all the jazz..One can spend ages trying to understand the theory, designing, buying hundred of crystals and sorting them, another black hole to walk into. Everything is revolving around Amateur radio and i am at the peripheral, trying not get sucked into it. I dont find the buccal speech, gibberish exchanges and constant battle with RFI in Ham radio appealing.
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Sadly, these generators have reliability issues. They don't have any fan cooling and it's easy to block the cooling vents underneath the sig gen. They then tend to run a bit hot, and this shortens the life of the electrolytic caps inside. The PSU and transformer are weak points in the design and can fail.
When the caps start failing the sig gen will produce quite a few low-level spurious signals on the output. The output mechanical step attenuator can get sticky and intermittent if not used regularly. For these reasons this sig gen probably isn't a good purchase in 2022 unless it has been serviced or the price is very low, and you don't mind doing the work yourself.
The RF performance is quite good, with low phase noise across the 2.5-50MHz range. Above about 520MHz it uses a doubler and the phase noise is relatively poor above 520MHz. The RF levelling accuracy is very good up to about 520MHz.
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We are posting at the same time. Oh well. I see them on ebay from time to time. So there is always a risk that they may fail.
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That's the idea although I spotted that you have 100kHz tone spacing in your example. That's still fine as long as you work out the correct frequencies to measure in each case.
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cheers. I have only noticed it now. I did it in a hurry writing the calculations in a napkin over lunch.