# 1GHz scope

#### tindel

Joined Sep 16, 2012
810
So I won the lottery and won a small contract to do some power supply design using GaN transistors, and now I need a real scope.

At previous employers, I've used Tektronix scopes for this type of development, but considering the insane price of the probes (IsoVu Isolated Probes | Tektronix), and somewhat small budget of the contract, I have to consider other methods for testing (math functions, single probe testing, etc.)

Requirements:
Minimum: 1GHz, Power Analysis features, Bode Plots (and function generator), Segmented Memory, reasonable Sample Depth (doesn't need to be too big though - this spec is a little overrated IMHO with segmented memory)
Nice to haves: MDO - I2C, CAN, High Speed Parallel Bus
Price point: Somewhat open, but I have a budget in mind.

I'm mostly looking at Keysight, Tektronix, R&S, and Lecroy. I've used Keysight and Tek scopes a lot, and am pretty familiar with their user interfaces and pros and cons. I've never used R&S and Lecroy though - so was curious to get input from others based on their experience. I've also thought about buying used - any experience here? Have folks had success negotiating lower prices or additional gear when you're spending this kind of money on a scope?

Really not interested in third-tier manufactures (Rigol, Siglent, etc), and will not consider them. I'm just not interested in hacking, buggy firmware, etc. I need professional gear.

#### MrChips

Joined Oct 2, 2009
24,625
I think you want to be looking at a Teledyne LeCroy WaveRunner or WaveSurfer.

#### rsjsouza

Joined Apr 21, 2014
335
In power supply design you may not need deep memory, thus a Keysight DSOX3104T or DSOX4104A could work (I tend to prefer the DSOX4000 series just because of the form factor of the display) - the used option mentioned by @nsaspook is quite interesting. You can also take a look at Keysight's official eBay store.

Back in 2019 I had a chance to play with the new Tektronix models MDO3 and MSO4 but I found them terribly slow. Some other folks reported the situation did not improve much better even after a few firmware updates.

A few years ago I had the opportunity to play with a R&S (RTA4000) and both its functionality and interface were quite good, but they are very expensive.

#### tautech

Joined Oct 8, 2019
217
Moderators
Please explain why my earlier factual post has been deleted ?

#### Wendy

Joined Mar 24, 2008
22,647
Becausr the TS specifically asked you not to refer to Siglent and you did it anyhow. Next step is a thread ban, which leaves you unable to interact with this specific thread.

#### tautech

Joined Oct 8, 2019
217
Becausr the TS specifically asked you not to refer to Siglent and you did it anyhow. Next step is a thread ban, which leaves you unable to interact with this specific thread.
Hmm, maybe you did not fully read my reply before deleting it in haste ?
I informed the OP many LeCroy models are in fact Siglent rebrands and suggested a model that was best bang for buck in this class of DSO.
What the OP chooses in the end is their business as we can only inform them of what's in the marketplace for them to consider.

As you own a Siglent yourself you could well have stated the OP's view they are full of bugs is misguided but instead you delete an informative post.

#### tindel

Joined Sep 16, 2012
810

#### tindel

Joined Sep 16, 2012
810

#### tindel

Joined Sep 16, 2012
810
In power supply design you may not need deep memory, thus a Keysight DSOX3104T or DSOX4104A could work (I tend to prefer the DSOX4000 series just because of the form factor of the display) - the used option mentioned by @nsaspook is quite interesting. You can also take a look at Keysight's official eBay store.

Back in 2019 I had a chance to play with the new Tektronix models MDO3 and MSO4 but I found them terribly slow. Some other folks reported the situation did not improve much better even after a few firmware updates.

A few years ago I had the opportunity to play with a R&S (RTA4000) and both its functionality and interface were quite good, but they are very expensive.

As you and nsaspook suggest, I have been watching the used market off and on for several years (dreaming mostly). I've been eyeing the MSO3104A for a long time. 4000 series hasn't gotten me too excited since the screen resolution isn't increased at all, but I could see how the larger form factor is beneficial. I've considered the 6000 series, but it's a bit out of my price range I think - but there's a used one that I could probably swing.

Do you have any pros/cons of the R&S4000? I did see that they had a special that had a fully loaded 4000 series for $10k. R&S Oscilloscopes Promotion | Full Bench. High Value. | Rohde & Schwarz (rohde-schwarz.com) Hard to beat a new scope and 3 year warranty with 1GHz BW for that price. Banner specs are a bit better than the Keysight too. #### rsjsouza Joined Apr 21, 2014 335 4000 series hasn't gotten me too excited since the screen resolution isn't increased at all, but I could see how the larger form factor is beneficial. This is just my personal opinion, but I like when the graticule is comprised of squares, not elongated rectangles. Both the 4000 and the 3000 share the same screen resolution, but the 3000 has a 16:9 aspect ratio, which turns the graticules rectangular. The 4000 has a 4:3 aspect ratio just like the older TVs. Do you have any pros/cons of the R&S4000? I did see that they had a special that had a fully loaded 4000 series for$10k. R&S Oscilloscopes Promotion | Full Bench. High Value. | Rohde & Schwarz (rohde-schwarz.com) Hard to beat a new scope and 3 year warranty with 1GHz BW for that price. Banner specs are a bit better than the Keysight too.
Unfortunately I was not able to do actual work with it, thus any comments from the are pure impressions and quick attempts to do things while I had time in front of it. I can tell it has a very nice screen, is very responsive, you can split the waveforms in small windows around the screen (although you can't necessarily resize them) and the low speed serial decoder that I looked seemed to work well (SPI). It also looks quite well built. Unfortunately that is all I can tell from what I remember.

#### tindel

Joined Sep 16, 2012
810
Well, I did end up making a purchase, and thought I'd let people know what I ended up doing in case they find themselves in a similar situation. YMMV, obviously.

I ended up purchasing the following:
MSOX3104T - Used from Keysight Ebay Store - fully loaded, all options, really a kickass scope - the best I've used.
DP0001A - Qty 2 - New - 400MHz high voltage diff probe
1147B - Qty 2 - New - 50MHz/15A Current Probe

The real difficulty ended up being in selecting and purchasing probes. A company in Germany clearly designed the HV probes and Keysight has licensed the tech. The OEM told me that I could buy them, but they had a 8-10 week lead time and they were very slow to communicate in general so I was not convinced they could deliver within that timeframe.

Rhode & Schwarz was a serious competitor. On paper they have better equipment than Keysight, at about 2/3 the price. But I couldn't get get my hands on the third-party probes to complete the transaction.

Lecroy had some functionality missing that the other competitors had available, which made their product offering clearly inadequate for my needs. Additionally, their website was clunky, and it was difficult to figure out what I really needed. I know they make good stuff, but they need to work on their website and customer service. I will say I also bought two T3PS23203P power supplies from Teledyne, and they have worked well so far.

Frankly, I'm not convinced I won't be limiting out the bandwidth of the HV probes, and will likely be forced to 'upgrade' to the Tektronix solution if I win follow-on funding, but this is a solid scope for 98% of the work I do, and at the stage I'm at. Please note that 'upgrading' to Tek is actually a downgrade in my mind, despite the higher price point. Their scopes have slower sample acquisition rate, slower firmware, buggy firmware, glitchy encoders, I could go on.... My understanding is that these probes are the only thing keeping them in business, and I hope their is a serious competing product on the market in the near future.