Hi All,
I've been watching Dave's videos for a while now and thought I would get involved here as well.
I just brought an Atten 1102CAL Oscillioscope off ebay. Very cheap, Spec looked good so I gave it a punt. It arrived very well packed and with out UK import duty!
I've had it about a week now, I was pretty happy to start with. The screen is great, viewing angle is good all round and it's 7 inches big!
PC Software, Easyscope is a bit crap but that doesn't really bother me.
The downside,
On both channels with no probes attached if you move the vertical position of the trace it moves away from zero (below) instead of staying at zero. This causes the measurement functions to report incorrect voltages. Now there should be no difference between a static measurement in the middle of the screen and one moved to the bottom of the screen, so this looks like a software bug to me.
I've repeated this with a probe clipped to it's own ground and the Scopes gnd test point, the result is the same.
At 2v's/dev the Vrms reads 0 whilst the trace is in the centre of the screen. Move the trace to near the bottom of the screen (at -6v) and now the Vrms read 400mV.
10v - 800mV RMS
5v - 600mV RMS
2v - 400mV RMS
1v - 40mV RMS
500mA - 20mV RMS
Again zero the channel and at all voltages the vRMS is 0.00v
Tried to contact Atten for a firmware update but had no response. Contacted the ebay distributor and they suggest sending it back to China, I'm not sure i want to do that so I might have to live with this issue. They also said Atten won't distribute firmware updates!
Unless someone out there has some Atten firmware.
My firmware version is 3.01.01.31
Hardware Version 6-4-2.1