1GHz scope

Thread Starter

tindel

Joined Sep 16, 2012
900
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.
 

rsjsouza

Joined Apr 21, 2014
367
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.

Good luck in your quest.
 

Wendy

Joined Mar 24, 2008
23,057
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
294
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.
 

Thread Starter

tindel

Joined Sep 16, 2012
900

Thread Starter

tindel

Joined Sep 16, 2012
900
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.

Good luck in your quest.
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
367
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.
 

Thread Starter

tindel

Joined Sep 16, 2012
900
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.
 

Thread Starter

tindel

Joined Sep 16, 2012
900
I'm very disappointed to post this update - but at this point I have to.

I purchased the products in post #13. The sales rep recommended the products I bought, so I expected them to work together upon receipt. Turns out that two DP0001A cannot be connected to a 3000 series scope at the same time. I've let my keysight sales rep and engineer know. They refuse to remedy the situation in any way. They no longer return my calls and emails. I literally have a $8k USD scope probe sitting on a shelf collecting dust.

After years of buying Keysight equipment with big corp ($100k's), and assuming that if I continued that trend with a 'reputable' company while paying the price premium for support that they would support me and my company as I have attempted to go off on my own. I was clearly wrong.

I'll let the reader make their own final conclusions - but wanted to point out that my experience has been that Keysight no longer values customer service. For all of their marketing directed at hackers and tinkerers - my experience has been that they don't support the hackers and tinkerers that are trying to up their game.

ETA: Here's my oscilloscope serial number so that they know exactly who is posting this: MY59242335
 
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crutschow

Joined Mar 14, 2008
30,835
Since Agilent split off from Hewlett-Packard and then Keysight split off from Agilent, I suspect their quality and customer service have slipped.
 

JohnInTX

Joined Jun 26, 2012
4,696
That's a shame. If you bought it from Keysight or their authorized distributor, they could have taken the probe back and re-sold it at a slight discount to the next customer. Then they'd have TWO happy customers singing their praises instead of one very unhappy one and another who may pass on the full price probe and look elsewhere. I got my Fluke 97 scopemeter that way from a distributor. The original customer didn't like it for some reason - after they stenciled the company's name on it - but Norvell took it back from them and sold it to me at a reasonable discount. The original customer bought something they liked better from them. Two happy customers.

Maybe keeping the visible sale on the books for the quarter was more important than the not-so-visible prospect decades of future business.
 
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Thread Starter

tindel

Joined Sep 16, 2012
900
This really kills me -

I've been a 15-year user and advocate for Keysight - I've used their gear as far back as HP branded gear and live in CO and know personally some of the engineers that designed the gear and have many 2nd and 3rd level connections to HP/Agilent/Keysight - particularly as I get my business going. I've previously advised my students to look around during their interviews and see what brands of equipment the companies use. I have previously told them that high tier companies use Keysight/Tek, and that I've personally turned down jobs that use Siglent and/or Rigol gear (not just because of that, but that was certainly one of the red-flags). But this experience has removed my rose-colored glasses.

I'm just sad that another company has bowed down to the almighty dollar to show larger quarterly gains while also alienating their customers for the future and I will certainly take my experience into account as my company rockets ahead.

I'm mostly posting this to let others know my experience. Yin vs Yang. This has been my experience - YMMV.

@JohnInTX You're right - simply making this right somehow would have solidified me a life-long customer. Instead, they are trying to 'fix' it by selling me more gear - further lining their pocket book - and further frustrating me - despite being told that the original solution would work.
 
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rsjsouza

Joined Apr 21, 2014
367
I am very sorry to hear this. There are a few long threads on the EEV forum about how Keysight is changing its customer service terms with the general public and leaving many hanging with unsupported products (this was after this thread was created, thus we that propped up Keysight did not know this).
 

Thread Starter

tindel

Joined Sep 16, 2012
900
I met with Keysight today.

After digging into @rsjsouza 's post, it dawned on me that this is a systemic problem at Keysight. I implored my sales reps that the company, as a whole, needs to reevaluate how they do business. I fully recognized that I was talking to the sales team, but I suggested that the CEO needs to read these threads both here and at eev, issue a public apology, and make things right if they really want to show that 'Keysight Cares'. I'm going to send an email with all of the relevant threads that I've seen to my sales channels and ask them to forward this information to their leadership (CEO, COO, CFO, and Global Sales). Therefore, If you know of any hobbyist or company has been burned by Keysight recently, please post your experience below. I am hopeful that the leadership team will read these and recognize that they are alienating the very people that have built their company, including their very own Founders.

It's clear that my sales reps are doing what they can to make my company whole within the guidelines of their policies, but it's crystal clear that the company is motivated by quarterly gains and not long-term growth.

Ultimately Keysight agreed to return the probe DP0001A for the full cost of purchase. I'm not sure I would have been so lucky if I hadn't had a company with rocket-ship growth potential and had showed them proof of that potential (and their potential future lost sales) and posted the issue publicly. I really feel for those hobbyists that are really getting screwed over right now because they are the ones that will have the next idea that will morph into a rocket-ship growth company in their garage, just like Dave and Bill did.
 
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