Hi guys,
I know this is an old thread but I recently got an FNIRSI-5012H to add to my T&M collection. I bought a FNIRSI-5012H directly from FNIRSI's official store on AliExpress to evaluate it myself.
https://www.aliexpress.com/item/33021370646.html?spm=a2g0s.12269583.0.0.6f82788eTtfVSJSurprisingly, FNIRSI provides a URL to the EEVblog YouTube video within their FNIRSI-5012H item page on AliExpress.
Of course, after I measured the actual bandwidth of the 5012H myself, I was disappointed like everyone else here. With a 25MHz 5V p-p sine, the FNIRSI-5012H is measuring 3.32V p-p. I measured the bandwidth of my FNIRSI-5012H at around 23MHz as 23MHz yields a -3dB amplitude drop.
I was not surprised; however, I contacted FNIRSI directly about the bandwidth issue and was shocked by their complete arrogance. FNIRSI tried to convince me that the amplitude drop from a 25MHz 5V p-p input measured by the 5012H as 25MHz 3.32V p-p is <quote> "normal and all oscilloscopes will measure the same" <quote>.
FNIRSI is claiming that the 5012H has 100MHz of bandwidth because the 5012H can measure frequency correctly, regardless if the amplitude is attenuated below -3dB.
I was expecting FNIRSI to claim it has 100MHz bandwidth under certain conditions, but they claim it fully meets their specifications which bothers me. I could care less about the money as it's nothing, but I absolutely do care about being grossly misled and that really annoys me. I requested to return the 5012H on AliExpress at the "official" FNIRSI store, but FNIRSI keeps refusing and saying that it does have 100MHz of bandwidth because it can measure frequency correctly regardless of a massive amplitude drop way below -3dB.
I would be very happy if it was advertised as having 20MHz of bandwidth and 250MS/s sampling rate, but then again, none of us would have bought it to see if it's really true or not.