It can sometimes be difficult to find the right product for you in the long list of products, which is why we have written this article. If you are interested in a cost-effective 2-channel scope, you can read this article . If you are looking for a cost-effective 4-channel scope, this article will help you choose. For 4-channel scopes up to 300MHz, read on.
Oscilloscope glossary
Do you have trouble with the terms used in this article? No problem! There is a knowledgebase article explaining terms that apply to oscilloscopes.
Content
- Important aspects 4 channel oscilloscope
- Specifications
- Strong points per oscilloscope (series)
- Conclusion
Important aspects 4 channel oscilloscope
Eleshop offers several 4 channel of different brands. A few important aspects of these oscilloscopes besides the bandwidth and the number of channels, are the sample rate, the memory depth and the waveform capture rate. The total sample rate is divided over the number of channels that the oscilloscope uses at a given moment. When all 4 channels are in use, the sample rate per channel is only 25% of the total sample rate and therefore a lot of resolution is lost. However, there are also oscilloscopes where certain methods or techniques are used to have 50% of the total sample rate available per channel. An example of this is the use of 2 AD converters. In most cases a sample rate of 1 GSa/s per channel is more than sufficient, but at 300 MHz a sample rate of 1 GSa/s per channel is quite tight.
The same effect is visible on the memory size as on the sample rate. The use of multiple channels reduces the number of points that can be stored per measurement per channel. As with the sample rate, it can also happen that 50% instead of 25% of the total memory size per channel is available.
Specifications
The table below shows the sample rate and memory size of the midrange oscilloscopes when all 4 channels are in use. These oscilloscopes are also discussed in more detail in this article.
| Brand & name | Sample rate | Memory size |
|---|---|---|
| Rigol DS4000E | 2 GSa/s per channel | 14 MPts per channel |
| Siglent SDS2000X | 1 GSa/s per channel | 35 MPts per channel |
| GW Instek GDS-2000E | 500 MSa/s per channel | 10 MPts per channel |
| GW Instek GDS-2204A | 500 MSa/s per channel | 2 MPts per channel |
| Rohde & Schwarz RTB2004 | 1.25 GSa/s per channel | 10 MPts per channel |
Strong points per oscilloscope (series)
In this section we look at the strengths of each oscilloscope or oscilloscopes of a series. To view the prices per oscilloscope in a certain series or for more information, please click on the product.
Rigol DS4000EThe DS4000E series is Rigol's answer to the demand for affordable and good 4 channel oscilloscopes. As you can see in the table above, the 2 GSa/s sample rate and the 14 Mpts memory size on each channel are very good for an oscilloscope in this class. Furthermore, the DS4000E series has a low noise floor, which provides a very accurate representation of the signal on the big screen of the scope. |
Siglent SDS2000XThe Siglent SDS2000X series has a huge total memory size of 140 megapoints and a sample rate of 1 GSa/s per channel. The SDS2000X oscilloscopes also apply a new SPO technology which results in reduced jitter, more sensitive triggering and a reduction of background noise. Besides the standard waveform capture rate of 140 000 wfm/s, these oscilloscopes can also capture 500 000 wfm/s. This is possible by first grabbing a larger block of a signal and then analyzing this block instead of simultaneously. This can be beneficial when debugging signals. |
GW Instek GDS-2000EThe GDS-2000E series is equipped with two AD converters, so when using two channels both channels have a sample rate of 1 GSa/s. The GDS-2000E also offers a good price/quality ratio. These oscilloscopes have a built-in voltage meter, which makes it possible to get a 3 digit display of VRMS values and there is also a 5 digit frequency meter available for clear frequency displays. The GDS-2000E series also has a low background noise of only 400 µVpp in the electronics are located |
GW Instek GDS-2204AThe GW Instek GDS-2204A oscilloscope features VPO (visual persistence oscilloscope) technology and has an update rate of up to 80 000 waveforms per second. The combination of the VPO technology and the update rate ensures that errors can be found quickly. The GDS-2204A comes standard with an RS-232C interface and like the GDS-2000E series, this oscilloscope also offers a good price-quality ratio. |
Rohde & Schwarz RTB2004The Rohde & Schwarz products are of a high quality and that is also the case with the RTB20004 oscilloscope from Rode & Schwarz. This oscilloscope also has a 10-bit A/D converter, so there is a fourfold improvement in display compared to the 8-bit A/D converter, which the earlier discussed oscilloscopes have. In addition, the RTB2004 has a capactive touch screen, so you can, just like on a smartphone screen, also control the scope with your fingers. Rohde & Schwarz also offers a wide range of options, making it possible to create an oscilloscope with the options that are relevant to you. |
Conclusion
The table quickly shows that both the Siglent SDS2000X and the Rigol DS4000E have good specifications. The Siglent SDS2000X series is also a lot cheaper than the other brands mentioned. However, these are not the only factors to compare the scopes on. In this segment it is important to check if the scope offers all the functions needed for the measurements. The Siglent offers many functions, but the Rohde & Schwarz is king in terms of expandability.
