Rigol DSA815 - problem with tracking generator?

[cyberfuzzy]

Hi. I'm not sure if there is a problem with the tracking generator of my Rigol DSA815. When I watch the signal with the scope it looks like the graph is not sinusoidal for <1 MHz.

I recorded a sweep from 500 kHz to 1.5 MHz, sweep time is 10 seconds:


On the spectrum analyzer the graph shows -18.1 dBm at 500 kHz and -19.2 dBm at 1.5 MHz. I don't think that the cable (RG-58) is that bad:


The setup is a cable from the tracking generator to the scope and back to the input of the spectrum analyzer:


Can anybody reproduce that issue? Is there a problem with my tracking generator or does every DSA815 act like this?

[cyberfuzzy]

According to this thread it seems to be normal for those cheap spectrum analyzers:
https://www.eevblog.com/forum/testgear/rigol-dsa-815-tracking-generator-distortion/

On my DSA815 the signal does not look sinusoidal for frequencies below 1 MHz. I took 3 screenshots with the scope for 10 kHz, 100 kHz and 1 MHz at zero span.