First cex:
In your pictures can not see any abnormal or symptoms about problems. Just normal.
(but of course I do not know your enviroment).
After scope is used more than example 100 - 200 hours keep it on least half to whole hour and do selfcalibration so that all connectors are empty and enviroment EMI is normal/low. Always also if temperature is more than 5 Celsius different as last selfcalibration done.
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I loose 3 pictures taken with scanning (scroll) mode and peak detect so later these for some kind of refeence.
These pictures have made with sure good perfect normal (new HW) SDS7102V / V2.4.1
All pics acquire is normal mode.
pictures have itself information about some settings so look these.
multiply x1
A: BNC open, normal sampling mode and memory 1k, BW full
B: Same but memory 10M (samplerate rise), BW full
C: Input x10, probe x10, probe adjust made as good as can. Probe connected to scope 1kHz out and GND also.
Memory 10M, note adjusted trig level and signal bottom level (and of course inputs are now DC mode! )
D: same but memory 1k
E: Probe as before: V/div adjusted and also trig level and signal bottom. Look carefully also trig level. Your picture need look nearly same.
F: Probe still connected and probe GND connected to center of probe (test pin) BW limited! Probe head free on the table not near any electronic or electric things.
H: same settings but BW full.
J: This GND wire connected to probe centerpin and opened so that it make nearly O. It is good poormans loop antenna (but with coax cable you can do much more better) Probe still 10x.
This antenna is on the IBM laptop,
M: Same but antenna moved and scope adjusted.
N: still same but "antenna" now different place on the laptop.
last pics just for fun.
With first pictures you can littlebit look if your scope looks around same.
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If measure continuous signals and want more accuracy, less noise use average.
If you afraid aliases with lower horizontal speed turn memory maximum. (and turn timebase more fast.
Sometimes good practice is start timebase from highest speed to dow. (many peoples have practice to adjust from low to fast... yes no problem if enough experience for avoid alias issues. Of course this is much more important with low memory scopes what drops dramatically fast sampling speed when go more slov horizontal speeds.
These pics are only for reference if someone think that there is something wrong in noise things in his scope.
(these are made with sure ok SDS7102 and in normal home enviroment without nearly any bad EMI noise, exept this computer just insie 30cm to scope and no any strong RF sources (TV, Radio, etc towers near.