Rohde & Schwarz Oscilloscopes - Questions/Comments? Let me know!

[nctnico]

I have some practical question - what software (better to be free) can be used to analyse RTB stored waveforms? I see RSCommander software from R&S, but it has some very limited analysing abilities for traces (no abilities at all, except for Y-setup).

That depends on what you want to analyse exactly. I've read CSV files produced by an RTM3004 into GNU Octave directly for analysis. In general you should forget about free software provided by the manufacturers. This usually is written by an intern and it can't do anything serious.

[LaurentR]

The RTB2K datasheet says that the input impedance of the scope is 9 pF ± 2 pF.

This is seems outside of the common compensation range of most passive probes on the market (typically 10-20 pF). Am I confused about the specs or this means only very select probes will be able to compensate properly?

[David Hess]

The RTB2K datasheet says that the input impedance of the scope is 9 pF ± 2 pF.

This is seems outside of the common compensation range of most passive probes on the market (typically 10-20 pF). Am I confused about the specs or this means only very select probes will be able to compensate properly?

Input capacitance at the oscilloscope limits probe bandwidth so a model which supports up to 300MHz will have a lower input capacitance than a model which only supports up to 100MHz.  Higher bandwidth passives probes have a lower capacitance compensation range.

This *is* annoying though if you are expecting to be able to use inexpensive 100MHz passive probes.

[mtdoc]

Hi,

I have some practical question - what software (better to be free) can be used to analyse RTB stored waveforms? I see RSCommander software from R&S, but it has some very limited analysing abilities for traces (no abilities at all, except for Y-setup).

I guess it would depend on what you want do with the data. There are numerous software packages that can display and analyze CSV files. As far a “free”goes, there’s the spreadsheet programs included in Libre Office, Open Office, and others. For more science/ engineering /computational focus there’s Octave and SciLab. I’ve used Scilab and it works well as a free alternative to Matlab. I’m sure Octave is good too. For just displaying the waveforms, there are dozens of free programs that will do that for CSV files. Just google “free cvs file graphing software”.

[LaurentR]

The RTB2K datasheet says that the input impedance of the scope is 9 pF ± 2 pF.

This is seems outside of the common compensation range of most passive probes on the market (typically 10-20 pF). Am I confused about the specs or this means only very select probes will be able to compensate properly?

Input capacitance at the oscilloscope limits probe bandwidth so a model which supports up to 300MHz will have a lower input capacitance than a model which only supports up to 100MHz.  Higher bandwidth passives probes have a lower capacitance compensation range.

This *is* annoying though if you are expecting to be able to use inexpensive 100MHz passive probes.

Thanks. Actually, it is the opposite. I was looking at the small 500MHz probes. The 3.5mm Tek P6139A / Caltest CT3290 (10-20pF) and the 2.5mm Keysight/Testec (also 10-20pF).

[2N3055]

Hi,

I have some practical question - what software (better to be free) can be used to analyse RTB stored waveforms? I see RSCommander software from R&S, but it has some very limited analysing abilities for traces (no abilities at all, except for Y-setup).

Octave and Scilab...

[mtdoc]

Thanks. Actually, it is the opposite. I was looking at the small 500MHz probes. The 3.5mm Tek P6139A / Caltest CT3290 (10-20pF) and the 2.5mm Keysight/Testec (also 10-20pF).

The input capacitance of the Tek P6139A and Caltest CT3290RA is 8pF not 10-20. Both have compensation ranges of 8-18pF.

I don't now what Keysight/Testec probe you are looking at but for the reasons David Hess explains, I'd be surprised if any 500MHz probe has an input capacitance of 10-20 pF.

[nctnico]

Thanks. Actually, it is the opposite. I was looking at the small 500MHz probes. The 3.5mm Tek P6139A / Caltest CT3290 (10-20pF) and the 2.5mm Keysight/Testec (also 10-20pF).

The input capacitance of the Tek P6139A and Caltest CT3290RA is 8pF not 10-20. Both have compensation ranges of 8-18pF.

I don't now what Keysight/Testec probe you are looking at but for the reasons David Hess explains, I'd be surprised if any 500MHz probe has an input capacitance of 10-20 pF.

Interestingly the RTM3004 (500 MHz 1Mh Ohm inputs) has a capacitance of 14pf so it caters for most probes. When dealing with high-Z probes the input capacitance doesn't matter much because it becomes part of the capacitive divider anway. It also shows that the probe itself will have a very high loading of the signal. I never use high-Z probes on signals over 100MHz because the signal will be loaded way too much to make a sensible measurement.

[MikeP]

Hardware wise, they have to be very careful in choosing OEMs who can provide the level of quality.  1 of 4 probes of my RTB2004 has loose connection on the x1x10 switch.  These small quirks could really affect the overall reputation of R&S.

 +1. Moreover, one of the probes is shorter by almost one centimeter. Once I was very puzzled. 

[LaurentR]

Thanks. Actually, it is the opposite. I was looking at the small 500MHz probes. The 3.5mm Tek P6139A / Caltest CT3290 (10-20pF) and the 2.5mm Keysight/Testec (also 10-20pF).

The input capacitance of the Tek P6139A and Caltest CT3290RA is 8pF not 10-20. Both have compensation ranges of 8-18pF.

I don't now what Keysight/Testec probe you are looking at but for the reasons David Hess explains, I'd be surprised if any 500MHz probe has an input capacitance of 10-20 pF.

Strangely, Tek quotes 8-18pF while Cal Test quotes 10-20 (that's where I got my original number from).

Also, for the Keysght/Testec probe, I am thinking of the N2873A. It claims 10-25 pF on the Keysight datasheet https://literature.cdn.keysight.com/litweb/pdf/5990-3930EN.pdf?id=1711400
What I believe is the same probe (Testec 12070RA/TT-HF 612 or RS Pro RS-HF 612RA) is quoted by Testec and RS-Pro as 10-20pF http://cdn-reichelt.de/documents/datenblatt/D100/TT_HF_612.pdf
It also looks the same (in black) as the Lecroy PP023, also quoted as 10-20pF
Not 100% sure if it's also the R&S ZP10.

[mtdoc]

Thanks. Actually, it is the opposite. I was looking at the small 500MHz probes. The 3.5mm Tek P6139A / Caltest CT3290 (10-20pF) and the 2.5mm Keysight/Testec (also 10-20pF).

The input capacitance of the Tek P6139A and Caltest CT3290RA is 8pF not 10-20. Both have compensation ranges of 8-18pF.

I don't now what Keysight/Testec probe you are looking at but for the reasons David Hess explains, I'd be surprised if any 500MHz probe has an input capacitance of 10-20 pF.

Strangely, Tek quotes 8-18pF while Cal Test quotes 10-20 (that's where I got my original number from).

Look at the P6139 manual and CT3290RA datsheet. Both are easily found online and both say 8pF

[David Hess]

Probe compensation specifications are not rigorous.  I was able to go through my cheap 100MHz probes which have a specified compensation range of  10 to 35 picofarads and find a pair which would work with 47 picofarad inputs.  None of my 250MHz probes could do this though.

[2N3055]

There is discrepancy about specs in documentation.

In datasheet it says: "Input impedance R&S®RTB2002, R&S®RTB2004 1 MΩ ± 2 % with 9 pF ± 2 pF (meas.)" ,
but in brochure it says "Input impedance 1 MΩ ± 2% with 19 pF ± 2 pF (meas.)"

Maybe a clarification by R&S ??

[nctnico]

19pf seems more likely so I guess the 9pf number is a typo.

[nctnico]

But at this pace, it'll take years... I waited for a 3000 series since last year... Not impressed so far..

I really hope new Rigol DS/MSO7000 shows to be decent performer...  They show an app bundle to be 1500€, R&S is 2500€ ... Basic scopes are not very inexpensive but give them time..

I'd be very amazed if the Rigol 7000 series is anywhere near the level of the R&S RTM3000 series at the introduction. However up to 200MHz there are more economic choices and the advantage of buying Lecroy, Keysight, R&S or Tektronix is minimal at best.

[2N3055]

19pf seems more likely so I guess the 9pf number is a typo.

I agree , but it's not a guessing contest. Datasheet has to be fixed..  For German prices I want German quality. No "Pluses" allowed..
If they want to justify high prices and their noble reputation  then they are held up to a higher standards..   
If not, then what is the difference to the Chinese ? Except Chinese charging much less?

[2N3055]

But at this pace, it'll take years... I waited for a 3000 series since last year... Not impressed so far..

I really hope new Rigol DS/MSO7000 shows to be decent performer...  They show an app bundle to be 1500€, R&S is 2500€ ... Basic scopes are not very inexpensive but give them time..

I'd be very amazed if the Rigol 7000 series is anywhere near the level of the R&S RTM3000 series at the introduction. However up to 200MHz there are more economic choices and the advantage of buying Lecroy, Keysight, R&S or Tektronix is minimal at best.

I actually think Rigol will give it's best to make it as good as possible. And R&S is not so good, firmware is still in flux.. Even with features..
As for what is good deal , full bundle in RIGOL is 1500€, a 1000€ less than others you mentioned. Their base prices are not so small, but they are free to adjust those..

[nctnico]

But at this pace, it'll take years... I waited for a 3000 series since last year... Not impressed so far..

I really hope new Rigol DS/MSO7000 shows to be decent performer...  They show an app bundle to be 1500€, R&S is 2500€ ... Basic scopes are not very inexpensive but give them time..

I'd be very amazed if the Rigol 7000 series is anywhere near the level of the R&S RTM3000 series at the introduction. However up to 200MHz there are more economic choices and the advantage of buying Lecroy, Keysight, R&S or Tektronix is minimal at best.

I actually think Rigol will give it's best to make it as good as possible. And R&S is not so good, firmware is still in flux.. Even with features..
As for what is good deal , full bundle in RIGOL is 1500€, a 1000€ less than others you mentioned. Their base prices are not so small, but they are free to adjust those..

1000€ on 10000€ is 10%. Is 10% cheaper worth the risk you get stuck with a lemon? At least the A-brands make an effort to fix the bugs in a timely manner. Still if a piece of equipment doesn't work the way you need it to work out-of-the-box the best course of action is to return it.

[2N3055]

1000€ on 10000€ is 10%. Is 10% cheaper worth the risk you get stuck with a lemon? At least the A-brands make an effort to fix the bugs in a timely manner. Still if a piece of equipment doesn't work the way you need it to work out-of-the-box the best course of action is to return it.

For 200 MHz 4ch difference is 4500€ to 6700€ (DS7024+bnd  vs R&S RTM3004 +BND) That is 50%.
If you want to buy older model LeCroyWS3024 (not Z, new one) there is a limited time bundle where you get 4ch/200MHz +budle for 4200€.
That one is a good deal. But if Rigol proves to be decent quality, it is a much more powerful scope than old WS3024.

Cheaper 200MHz scopes are not in that class. Only one that comes close is GW Instek. That is a viable option.

New R&S 2000/3000/4000 are new platform, with GUI that is so much more modern than Keysight one.  I like them in general. I like R&S in general.
Their pricing is not attractive though, even compared to Keysight, that shows signs of adjusting prices lately...  Keysight are sorely in need of a new generation of scopes, and if they don't have one ready to release, they will have to decrease prices to buy time...

Market is changing. They will HAVE to start giving basic bundles included in base price. They will have to adjust options prices. It's just nobody wants to be the first one to blink while playing chicken. But, if Chinese make a first move, they might start grabbing market share.

We'll see. Interesting times.
Regards,

[mtdoc]

The RTB2K datasheet says that the input impedance of the scope is 9 pF ± 2 pF.

This is seems outside of the common compensation range of most passive probes on the market (typically 10-20 pF). Am I confused about the specs or this means only very select probes will be able to compensate properly?

The discussion here had me curios, so I did some testing:

I meausured the input capacitance of my RTB2004 with my DE-5000 LCR meter and got 10pF.

I was easily able to properly compensate multiple oscilloscope probes I have laying around including:

Tek p6106, p6136 and p6137 probes and several different cheap chinese probes I had laying around including the ubiquitous p6100.

All had no problem being adjusted to proper compensation.

Interestingly, the 300 MHz RT-ZP03 probes supplied with the scope have a specified input capacitance of 12pF but there is no compensation range specified on the datasheet.

So as David Hess says, probe compensation specs are not rigorous.

Any of the probes you're looking at will work fine the the RTB2004.

[2N3055]

The RTB2K datasheet says that the input impedance of the scope is 9 pF ± 2 pF.

This is seems outside of the common compensation range of most passive probes on the market (typically 10-20 pF). Am I confused about the specs or this means only very select probes will be able to compensate properly?

The discussion here had me curios, so I did some testing:

I meausured the input capacitance of my RTB2004 with my DE-5000 LCR meter and got 10pF.

I was easily able to properly compensate multiple oscilloscope probes I have laying around including:

Tek p6106, p6136 and p6137 probes and several different cheap chinese probes I had laying around including the ubiquitous p6100.

All had no problem being adjusted to proper compensation.

Interestingly, the 300 MHz RT-ZP03 probes supplied with the scope have a specified input capacitance of 12pF but there is no compensation range specified on the datasheet.

So as David Hess says, probe compensation specs are not rigorous.

Any of the probes you're looking at will work fine the the RTB2004.

That's a good work! Thanks for that, now we know. So it is 9pF...

[David Hess]

Lower oscilloscope input capacitance has obvious advantages but it also comes at a price.  The smaller gate geometry FETs needed have higher noise and the lower capacitance also makes input protection circuits more difficult.  Some active probes leave out input protection entirely in the quest for the lowest possible input capacitance but they are very easily damaged by ESD.

10 picofarads for a 300 MHz input strikes me as a little extreme but maybe Rohde & Schwarz is reusing the input circuits from their 500 MHz instruments or wants to share probes with them. 

Such a low input capacitance does make probe design easier though.

One thing I miss on newer oscilloscopes is being able to adjust the input capacitance so I can swap probes around without adjusting compensation.

[glowman]

Just checked the firmware page for RTB2000 minutes ago and found out the new 2.121 is now there.  However, the release notes, etc. has 2.101 as the label although upon checking the release note, it is the new 2.121.   There is really something wrong with these people... If they are that careless, what can you expect with regards to the quality of their products in general.  No wonder you could easily find bugs.  Seems like they never do debugging and hassle their users to find them.  I was tempted to ask... is this R&S Germany?

Whether its the fault of their web administrator or the firmware engineers, it affects R&S as a whole.  Kindly please get your act together.

PS. If you refresh the page several times, firmware 2.000 may appear but, if you're lucky to see the 2.101, it's the 2.121... funny.

[hwj-d]

@glowman,
be patient, give them a chance to make it a good work and product; they work on it.
(There are other products from other big companies, they annoys me more, in the moment.)

 

[nctnico]

Just checked the firmware page for RTB2000 minutes ago and found out the new 2.121 is now there.  However, the release notes, etc. has 2.101 as the label although upon checking the release note, it is the new 2.121.   There is really something wrong with these people... If they are that careless, what can you expect with regards to the quality of their products in general.  No wonder you could easily find bugs.  Seems like they never do debugging and hassle their users to find them.  I was tempted to ask... is this R&S Germany?

Whether its the fault of their web administrator or the firmware engineers, it affects R&S as a whole.  Kindly please get your act together.

PS. If you refresh the page several times, firmware 2.000 may appear but, if you're lucky to see the 2.101, it's the 2.121... funny.

I suspect this is Cloudflare messing things up in combination with the wrong caching settings on the web server. Removing something from internet can be hard especially with caching web proxies in between.