This PC oscilloscope works good for a rough tracking of AC signals in a limited frequency range with little accuracy. Because I needed to watch and DC signals (pulses), I sought a better solution.
Offer of the PC oscilloscopes is very wide, from single channel probes through 4-Channel Digital Oscilloscopes up to high frequency oscilloscopes with prices up to $10 000. In fact we could say that the PC oscilloscopes are not significantly less expensive and are now offered stand-alone oscilloscopes with similar parameters even in the lowest price cathegory. I was determined to buy this model from OWON company, when I found this shop. Very tempting prices of stand-alone oscilloscopes, 40 MHz oscilloscope with 500ms/s sample rate for $360, it is unbeatable offer! I registered and I wanted to buy, but then I noticed I'm only 77-th registered customer and the store works very briefly. Mistrust prevailed and I resigned from the purchase. Too tempting offer in a very new shop with a minimum of customers is simply too risky for me.
I finally decided to PC oscilloscope DSO-Voltcraft 2090th. 2 channel 40 MHz digital oscilloscope with 100ms/s sample rate, max input voltage of 35V. The parameters are a compromise with the price, but the purchase was carried out from proven brands so little risk. Price 5500 CZK ($ 295) including transport. Producer of those scopes is Chinese firm Hantek. The software for Linux is also available, but manufacturer provides only software for Windows.
The probe device does not come with, so I had to buy a probe separately. I chose a universal probe with ratios 1:1 and 1:10 and trimming elements for 700 CZK.
On the photos you can see the inner structure of oscilloscope and quality of construction. I think it's good. Input components are separated by shielding plates, inside a plastic box is also wrapped with foil shielding. I have no ambition to perform some extensive quality testing, have not the right equipment and knowlidge. So far I have used this oscilloscope twice and each time it worked as expected. The oscilloscope is equipped with a rectangular 1kHz signal generator, which the osciloscope displays perfectly. Also, the control signal from the transmitter looks like it had. So I'll see in the future if any problems occur. So far I am satisfied.