Surprise, surprise! Apparently, the firmware update to 00.01.17.00.04 has enabled the 10Hz RBW option on my DSA815-TG! Though I didn't find this specified anywhere. Either the new firmware must have enabled this or my "messing around" with up- and downgrading several times.
Okay, I just re-checked: If I downgrade to 00.01.16, the minimum RBW is again 100Hz, after the upgrade to 00.01.17 it returns to 10Hz.
So I'm quite surprised why Rigol didn't report this in their changelog, or maybe it's unintentional, a "bug" so to speak
. I love these kinds of bugs...
Now it's a hard decision, rather have the trial options or the 10Hz RBW. I guess for me the 10Hz is more valuable since I hardly used the options for anything else than playing around, while I often whished I had better frequency resolution. Lets see, if this "bug" gets eliminated in the next update...or if it's a "si(g)lent" improvement to have a better standing against the competitor
.
Cheers,
Thomas