quality of cheap 5 in 1 oscilloscope from ebay

Thread Starter

ninjaman

Joined May 18, 2013
311
hello,

i bought a 5 in 1 oscilloscope for £65 off ebay
i have tried to make a diode clipper circuit and measure the 0.7 volts of the diode in both directions, cathode to ground and anode to ground. i did get a sine wave going positive with a -700mv (approx) and the other way i measured 400mv (approx)
when i disconnected the probes there seemed to be some voltage measured on the screen. could this voltage be a calibration issue?
the value is only small.
this is the web page that i am using for the experiments
http://www.electronics-tutorials.ws/diode/diode-clipping-circuits.html
i tried to measure the voltage of a single AA battery. i measured the battery with my multimeter and got 1.6 volts, the battery is brand new. then i measured the battery with the scope and got 1.2v
not sure what is going on here.
any help, is there a way that i could check the scope more accurately?

thanks
 

BR-549

Joined Sep 22, 2013
4,938
I never used one of those pc scopes. Most regular scopes have a little calibration tab, you can attach your probe to.

And most manuals have a calibration procedure.

If you want your display to be like the link's examples......check your ac-dc mode settings.
 
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