My entry level DSOs: First impressins
DS1104Z
This is a handy, compact 4-channel oscilloscope which has a lot of software features, and can be used for development and debugging of most of the microprocessor, controller, audio and video devices.
It has deep memory (25M samples on single channel, 12.5M samples on dual-trace mode, and 6.25 Msamples in the single channel mode). Like many entry level scopes, it has a time-interleaved 8-bit ADC sampling input signals at 1Gsa/s. The input channels are bandwidth limited around 140MHz which is OK assuming that the main value of this scope is 4 channel acquisition at 250Msa/s.
It is quite affordable and reliable, does not look ugly. It comes with decent passive probes.
There are few interesting features:
It does not have a dedicated trigger input or channel. The detection of trigger condition is exclusively on the samples from one of the channels, selected as trigger source. It allows to do naturally glitch, pulse duration and other standard for digital scope trigger modes.
Interestingly, it used full sample memory to store multiple captured frames, when less than full memory is needed (one can set 30, 300k points for instance), and then displays all frames simultaneously to emulate analog scope "natural" persistence. This feature together with soft trigger plays a bad trick on fast signals - it is possible to let it display time going backwards! Also, the digital filter used in 4-channel mode (probably, a kind of SINC FIR filter) rings on the edges, so fast edge waveform looks a bit different in a single and multichannel mode. All these "defects" are only visible in extreme stress cases, and the scope perfectly displays clock and data signal in the comfort zone below 30-50MHz.
To my surprise, I did not notice any aliasing when sampling, say, 30MHz sinewave at 5MSa/s. Other oscilloscopes simply decimate points, and that sometimes confuses the user when one does not notice that the sample rate is below Nyquist. This one probably always samples at maximum sample rate, and then applies a digital filter to get decimated point. So instead of confusing undersumpled waveforms, it displays a smeared picture clearly inviting to increase sample rate.
The strong feature is protocol decoding - it detects and decodes I2C, UART, SPI and few other protocols. While at the first glance it is handy, the limited screen window allows to use it only for very limited tasks. But for much more convenient analysis and more protocols I'd recommend transferring data to PC via USB or, better, 1Gbit/s Ethernet.
The great advantage vs other entry level scopes is full support of LXI/VISA. The user can control acquisition and access data from own applications in Python, Matlab and (who likes) Labview.
Overall it is a solid performer at budget price.