2-Channel 10OMHz Oscilloscope Rigol DS1102Z-E or Siglent SDS1102CML

[radiohomebrewer2000]

Hello,
Which oscilloscope is better for someone who has not used an oscilloscope?

Rigol DS1102Z-E
Siglent SDS1102CML

Both are 100 MHz 2-channel Oscilloscopes.

Right now, Amazon has the Rigol DS1102Z-E for US$279.  A few days ago, it was $329.
Amazon has the Siglent SDS1102CML for $319.

I am not committed to Amazon.  Just a place I have been looking.

I am trying to work my way through the Problems (Lab Exercises) in the book Electronics of Radio by David Rutledge.  I will be building the Norcal 40A Transceiver.  I have most of the parts.  Many of the problems in the book use an oscilloscope and a arbitrary wave form generator.  I have a multimeter and antenna analyzer.  I still need to get all the BNC connectors, adapters, cables, tee, etc.   This is fine because many QRP hams use BNC instead of UHF (PL259/SO239) RF connectors.   For the longest time, I have been using the UHF connectors unless the device came with SMA or N connector(s).

I may go cheap on the signal generator for about US$100 you can find on ebay, amazon, and aliexress.

However, I want a good oscilloscope for the beginner.  I looked at Hantek earlier, but then decided against it. 

I need at least a 100 MHz bandwidth and 2-channels.  4-channels is out of my price range.
I prefer 200 MHz bandwidth.

I need to measure the 40 meter (7 MHz) ham band.  The upper end of the band is 7.3MHz in the USA.  But I prefer to be able to measure up to the 10 meter (28.0 - 29.7MHz) ham band.

The Problems in the book measures something as low as a 10Hz signal at 1Vpp.  But something that can measure a radio where the RF Output is 5 Watts or less.  I am into building QRP radios.  I want to get to the point where I can design and home brew my own.  However, I need to pay my dues by experimenting, testing, measuring, doing the math... And when I fail, look into why I failed and see if I can fix it.    And I have additional books to help with electronics and math to fill in the missing gaps in my knowledge/experience.

On the Siglent oscilloscopes, you can see the numbers and lines on the grid for the FFT.  I think the numbers are called Markers?



And if you go to 11:19, you can see what I am talking about.
This make it easier for me to see where the signal is plotted.

I cannot afford a decent oscilloscope, signal generator, and a spectrum analyzer.  So, hopefully, the FFT on an oscilloscope can help here.

I have been unable to see if the Rigol can do this?  I have searched and searched and yet to see where something shows these numbers.  I like see to -10dB, -20dB, -30dB, -40dB, etc.   And I would like to see horizontal and vertical lines.

I want to see if the harmonics have been attenuated enough.   And it really helps if the lines and numbers show up in the graph.

Thanks,
Daniel

[Fungus]

On the Siglent oscilloscopes, you can see the numbers and lines on the grid for the FFT.  I think the numbers are called Markers?



And if you go to 11:19, you can see what I am talking about.

Don't confuse the X-E models (ie. the one in that video) with the CML models. The X-E is much more powerful and does more things.

I don't think the CML model has FFT markers or long FFT so it won't show all that detail.

I'm sure the resident Siglent reps will give us the exact details.

[Zenith]

I've got a Siglent SDS1052CML+. I haven't used the FFT feature much, but it seems quite crude, not like in the video. I have a spectrum analyser anyway.

I've found it to be a nice scope to use and I've been pleased with the purchase. It's been around for a time and seems to be heading towards dropping off the price list. The Siglent SDS1202X-E looks much more capable for not that much more money. That's casually looking at UK prices.

The Rigol DS1102Z-E looks to be more up to date and has more features than the Siglent SDS1052CML+, but that's just at a glance. I've no idea what the FFT feature is like. At present it's on special offer. Rigol scopes generally have a good reputation.

Hantek and Owon have a name for firmware bugs they are not quick to fix.

I'm sure someone will be along who has had hands on experience with all three scopes to give you a better informed opinion.

[armandine2]

I often look to see what's on someones bench:

It looks like Bill at Lockdown Electronics has a Siglent SDS1104X-E - he has done some oscilloscope training videos, which may be useful.

[tautech]

Welcome RHB2k.

SDS1202X-E is certainly a lot more scope for not a lot more cost that SDS1102CML+ and the primary reason we no longer stock CML+.
However if you can sacrifice some BW the newer 4ch SDS1104X-U has a better FFT, sure not 1 Mpts as X-E models have but a full set of peak markers that the SDS1202X-E doesn't have although we have asked for the same FFT features as are in the 4ch X-E models.

From:
https://int.siglent.com/products-overview/sds1000xu/

[Performa01]

So your key-requirements are high bandwidth and a decent FFT for spectrum analysis. You don’t need four channels, but as always, it has to be cheap.

I think there is no alternative to the more modern Siglent offers. Most everything else either lacks bandwidth or a powerful FFT – or both.

The SDS1202X-E (list price $379,-) has two channels but 200 MHz bandwidth – actually it’s more like 240 MHz. It has a 1 Mpts FFT, but no marker tools. You don’t strictly need them, there are still cursor measurements available. Few DSOs provide markers, even at a much higher price…

The SDS1104X-U (list price $399,-) has four channels, but only 100 MHz bandwidth. The FFT is has markers but is limited to 128 kpts.

The best, but also most expensive, would be an SDS 1204X-E (list price $775,-) with four channels, 200 (240) MHz bandwidth, 1 Mpts FFT with all the marker tools, or an SDS1104X-E (list price $499,-) hacked to full bandwidth, as it’s popular in this forum.


Whatever you go for, be aware that using the FFT is not so straight forward for the inexperienced. With a careful setup you can get fantastic results within the bandwidth of the DSO, that need not hide behind the average low end spectrum analyzer, but to achieve this you need some different or even additional considerations to what would be required to get the most out of a traditional spectrum analyzer.

Unfortunately, the guy in that video appears to be one of those who don’t really have any clue what they’re doing. Consequently, he’s showing rather awful and even meaningless results. An SDS1202X-E can do much better…

See the attached screenshot, which shows the cursor measurements on a narrowband modulation spectrum using a very early version of the FFT in an SDS1104X-E, where no markers have been implemented yet. This takes advantage on the long 1 Mpts FFT as it’s capable to separate the sidebands from the 28 MHz carrier, even though the modulation frequency is only 1 kHz.

SDS1104X-E FFT Mod 28MHz_AM_1kHz_90% split

A different scenario shows the spectrum of the same signal up to 100 MHz. You can see the harmonics together with some spurious signals, but you still get almost 70 dB dynamic range, which is quite comparable to traditional entry level spectrum analyzers.

SDS1104X-E FFT Full 28MHz_AM_1kHz_90% split