I assembled dso150, and i have a problem with noise and voltage measurement. No matter if I'm in GND, DC or AC coupling there is high 2kHz noise, which makes my readings wavy and not accurate. Also I can't calibrate the vpos because after i do it the trace is going away(after some time) from center/yellow arrow. It messes up my voltage readings, only Vpp is accurate. Voltages on analog board are ok(V+ and V- are a bit low, about 7.5v and -6.5V). My software version is 064, board number 109-15000-00E1. Also C3 and C5 regulation don't seem to make any difference in shape of a test wave. Sensel0-3 signals are also OK.
I made a video to show some more about my problem: https://www.youtube.com/watch?v=iK8eN5_mOF0. In about a minute trace gone down by about 1 division
Noise and voltage reading problem
Re: Noise and voltage reading problem
What kind of power supply did you use? It is suggested to check power supply and the negative voltage generator (U5 and related parts on the analog board).
Re: Noise and voltage reading problem
9V battery, V+ and V- are kinda low. Bought even better branded battery, and the problem is still here. I measured that when I power on the DSO, battery voltage drops about 1V, a bit too much for a 120mA current?
Re: Noise and voltage reading problem
I guess you should have an "E" version (or F version) analog board. Please check C11 (replace it if you have another one). If you have the older C version analog board please check C13 and C14. The board version is the last letter in its part number. The number read like this: 109-15001-00X.
Re: Noise and voltage reading problem
Soldered new one and problem remains i have F version of the board
Re: Noise and voltage reading problem
Plugged it to a lab bench @9V and working like a charm, turned out it was happening because of the voltage drop of 9V battery.
Thanks for help, thread to be closed
Thanks for help, thread to be closed
Re: Noise and voltage reading problem
May I give you a tip? I use this '9V' 300mAh NiMH battery (8,4V) from Conrad without any problem:
https://www.conrad.nl/nl/oplaadbare-9v- ... 05467.html
It remains most of the discharge time above 8V, and it runs at least 2 hours before charging is required.
(The scope is going weird below 7.5V ) And a charged spare battery can be handy....
https://www.conrad.nl/nl/oplaadbare-9v- ... 05467.html
It remains most of the discharge time above 8V, and it runs at least 2 hours before charging is required.
(The scope is going weird below 7.5V ) And a charged spare battery can be handy....