# Two question about 403

**URL:** <https://forum.quantasylum.com/t/two-question-about-403/2216>\
**Category:** Uncategorized\
**Created:** [February 17, 2026, 4:36pm UTC](https://forum.quantasylum.com/t/two-question-about-403/2216 "2026-02-17T16:36:03Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![walge](https://avatars.discourse-cdn.com/v4/letter/w/7bcc69/32.png) [@walge](https://forum.quantasylum.com/u/walge)\
**Post date:** [February 17, 2026, 4:36pm UTC](https://forum.quantasylum.com/t/two-question-about-403/2216/1 "2026-02-17T16:36:03Z")

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HI

with 403x sw is it possible to do a plot, p.e. of frequency , and then do another plot leaving the previous one on screen? Same as AP do.

Second question, there is a trick to undertstand if one value of Vin on 403 is close to the limit for the selected attenuation? I see that for 0dB the max is 2 Vrms, correct?

Each time I turn on the 403 the selected attenuation is 48 dB, in automatic, right?

( I hope that my question are clear) 🙂

Thanks

Walter

In some case I go over but