Finally I had some time to actually test the Quad and here’s a brief summary of my thoughts and observations (this is an engineering pre-production sample). A handheld DSO is somewhat novel as there aren’t many competitors around with specifications and pricing matching the Quad. So doing a comparison is difficult, but one appropriate question to ask might be if this is a toy for the hobbyist or a tool for the professional?
The four probe connectors are smaller than on the Nano and probably appropriately so as the unit packs a lot of features in a small package. Overall design looks and feels good. I like the top four push buttons, but less so the two slide left/right buttons. They are in my opinion too small, feel flimsy and prone to fail. They may tolerate more “abuse” than I think, but this is for time to tell. The oscilloscope style probe looks well made, but the black and red hook probes again are too small and delicate for normal use (they may however be appropriate for SMT probing).
The quad has two analog channels (72Msa/s) and two logic only channels (sample rate unknown). Both for hobbyist and professional this is a useful combination to have in a single instrument. User interface requirements however differ significantly between analog and logic channels so it will be quite a challenge to get this right for both. Sample rate is sufficient for a wide range of practical measurement challenges (analog waveforms up to about 7MHz).
One might expect that primary use for a handheld DSO is in the field. I doubt however that the Quad will face up to the elements well and so may be more appropriate for the lab. Further to this, I find the storage capacity of 2MB too small (not expandable as far as I know). When in the field you want to record measurements, bring along sample waveforms and then you’re likely to wish for more. For lab use this is less of an issue since you’re likely to have access to a laptop/desktop where you can upload measurements.
I’m missing a real time clock that would allow me to time stamp saved waveforms and measurements.
My sample came without a power switch (the slider is missing).
Hardware defines the overall feature set and the precision/accuracy we can achieve in terms of measurements. This is typically the main (and quite often the only) aspect considered prior to buying. Software on the other hand defines the users experience and to a large extent determines what customers will think of the product once they actually own it (will they use it and will they recommend it to others).
Sadly to say, the current firmware is in a horrible state. It appears to be based on the Nano 2.5e version with all the mistakes of the past present in abundance. This looks like something a hardware engineer would put together in a couple hours just to test as much of the functionality as possible from a single screen. Navigating the various options take you on a wild tour around the full display with no apparent logic. Knowing where to go for what is just about impossible to guess and if you have an idea, getting there is even worse.
The only feature I could get to work with some success was displaying a repeating waveform with AUTO trigger. At T/Div’s less equal to 1us however, the waveform was lost and the display started to live a life of its own. Nearly all other options are either not working at all or doing something different than what I would expect.
At this stage I think further testing is pointless. First priority should be to get the basics right. That is sampling, buffer management, triggers (AUTO, NORM and SING) and waveform display. Until this is right, nothing else is relevant. In my experience it is always better to include a small feature set that works well rather than a large feature set with lots of issues.
Going back to the initial question (a hobbyist toy or a professional tool) I’m leaning towards the hobbyist and student. The hardware has plenty of features that would cover the needs of professionals and hobbyists alike, but I’m afraid exposing it to the elements is more than it can handle.
As I see it, the present state of the firmware prevents any practical use of the Quad as a DSO and measuring instrument. Get the basics right, remove all non-working features, seek help with the user interface (think in terms of menu hierarchies and use cases) and then let us test again.