R&S RTM3004 The Swiss-Knife-Oscilloscope

[Rich@RohdeScopesUSA]

Thanks for the tear down Mike - the scope looks to be very nicely built. The front end amplifiers needing such a heatsink surprised me though. The equivalent part on the Keysight 2000/3000 scopes has nothing.
Could this be a product of them trying to go for lower noise because of the 10 bit ADC?

Also seems like the noise performance is better than the competition (it has to be to get the most out of that 10 bit ADC on the low ranges).

In general, comparing apples to apples, they will have noise 1/2 to 1/5th the competitions' noise at the most sensitive volt/div settings (AC RMS, same bandwidth, % of screen to account for different numbers of divisions between different scopes).   This was an area we really focused on for these products as you've typically had to buy a much more expensive scope to get this type of noise performance at this bandwidth.  In addition, with the 10-bit ADC, it just makes sense.

-Rich

[nctnico]

Being able to drag menu items onto the screen seems a useful feature me. It basically allows to create short cut buttons on the fly. One question though: do these remain after a power cycle?

[Rich@RohdeScopesUSA]

Being able to drag menu items onto the screen seems a useful feature me. It basically allows to create short cut buttons on the fly. One question though: do these remain after a power cycle?

They do.  They also remain after a preset (default setup).  You can delete one (or all) by clicking the little "settings" icon on one. 

-Rich

[mikeselectricstuff]

Being able to drag menu items onto the screen seems a useful feature me. It basically allows to create short cut buttons on the fly. One question though: do these remain after a power cycle?

Yes.
And also over a preset and Autoset, but not saved & reloaded when saving/loading setup. AFAICS there is no way to save pulled-out menus

[nctnico]

Being able to drag menu items onto the screen seems a useful feature me. It basically allows to create short cut buttons on the fly. One question though: do these remain after a power cycle?

They do.  They also remain after a preset (default setup).  You can delete one (or all) by clicking the little "settings" icon on one. 

That is pretty neat especially since a preset doesn't whipe them out

[mikeselectricstuff]

One minor issue - some menu items are context sensitive - e.g. trigger. you can pull these out, and they stay there even when something is chnaged that would make them no longer appear in the menu - maybe the pulled menus should be greyed out in this situation ?

e.g. trigger->risetime", pull out "rise time" thene select a different trigger type
 
I was going to try something really silly but it seems you can only have up to 10 pulled-out menus onscreen at once!

[JoHr]

One minor issue - some menu items are context sensitive - e.g. trigger. you can pull these out, and they stay there even when something is chnaged that would make them no longer appear in the menu - maybe the pulled menus should be greyed out in this situation ?

e.g. trigger->risetime", pull out "rise time" thene select a different trigger type
 
I was going to try something really silly but it seems you can only have up to 10 pulled-out menus onscreen at once!

LOL ... what kind of weird things are you doing to need more than 10 extra menu keys?

[mikeselectricstuff]

One minor issue - some menu items are context sensitive - e.g. trigger. you can pull these out, and they stay there even when something is chnaged that would make them no longer appear in the menu - maybe the pulled menus should be greyed out in this situation ?

e.g. trigger->risetime", pull out "rise time" thene select a different trigger type
 
I was going to try something really silly but it seems you can only have up to 10 pulled-out menus onscreen at once!

LOL ... what kind of weird things are you doing to need more than 10 extra menu keys?

Who said anything about "need"?
Just wanted to fill the whole screen with pulled-out menus for fun...

[nctnico]

I'm sure I would want 11 at some point 

[RobBarter]

I'm desperately trying to find a reason for 'not' buying this scope....'need' is not a reason in my book especially when it's for me     However, 'only' having 10 extra menus on screen...well....

[JoHr]

I'm sure I would want 11 at some point 

Everything except   "unlucky numbers" ... language sensitive of course

[nctnico]

I'm desperately trying to find a reason for 'not' buying this scope....'need' is not a reason in my book especially when it's for me     However, 'only' having 10 extra menus on screen...well....

It looks tempting but the firmware still needs some TLC and no thourough review yet.

[mikeselectricstuff]

Minor bug - if decodes are on when you slow down timebase to the point roll mode kicks in, it freaks out, and decode doesn't self-recover after setting timebase back to normal mode.
It should just suspend  decodes while roll mode is active.
https://youtu.be/yaicDDGWvtE

[mikeselectricstuff]

I'm desperately trying to find a reason for 'not' buying this scope....'need' is not a reason in my book especially when it's for me     However, 'only' having 10 extra menus on screen...well....

It looks tempting but the firmware still needs some TLC and no thourough review yet.

All the RTB2004 reviews apply to this unit as it's a superset of functionality. I have plans to look at a few of the new features - let me know if there's anything specific you're interested in

[GeorgeOfTheJungle]

Mike here's something you could check: with the raster set to slow speeds (say 100 or 200 ms/div) see if it can decode properly a few chars arriving at ~high speeds (4Mbaud?) in the same or in another channel. The siglents I've tried can't do that properly, the rigols yes, and of course the agilents too.

[mikeselectricstuff]

Mike here's something you could check: with the raster set to slow speeds (say 100 or 200 ms/div) see if it can decode properly a few chars arriving at ~high speeds (4Mbaud?) in the same or in another channel. The siglents I've tried can't do that properly, the rigols yes, and of course the agilents too.

That will probably just be an acquisition memory depth issue - at 200ms/div it's probably not going to have enough sample rate to resolve the data. RTM3004 seems to be OK with 250kbaud at 1 sec/div

[GeorgeOfTheJungle]

But in theory it's a hardware decoder, doesn't that mean it's not reading/decoding sampled data but feeding it into an uart?

[mikeselectricstuff]

But in theory it's a hardware decoder, doesn't that mean it's not reading/decoding sampled data but feeding it into an uart?

I think it would be working out of the acquisition memory - it would get very complicated to keep seperate data for the decodes.

[nctnico]

But in theory it's a hardware decoder, doesn't that mean it's not reading/decoding sampled data but feeding it into an uart?

I think it would be working out of the acquisition memory - it would get very complicated to keep seperate data for the decodes.

And yet I think Keysight and MicSig do that. If you keep timestamps on the decoded data they can be lined up when displaying.

[mikeselectricstuff]

But in theory it's a hardware decoder, doesn't that mean it's not reading/decoding sampled data but feeding it into an uart?

I think it would be working out of the acquisition memory - it would get very complicated to keep seperate data for the decodes.

And yet I think Keysight and MicSig do that. If you keep timestamps on the decoded data they can be lined up when displaying.

If not the actual memory it certainly seems to be constrained by the sample rate, in that decode fails when the waveform becomes too visibly distorted by undersampling.
For a 250kbaud UART, which is what I happen to have set up now, the MSOX3104T decodes down to 50ms/div, the RTM3004 to 1 sec/div

[JoHr]

Minor bug - if decodes are on when you slow down timebase to the point roll mode kicks in, it freaks out, and decode doesn't self-recover after setting timebase back to normal mode.
It should just suspend  decodes while roll mode is active.

Looks like the protocol decode is n/a in roll mode ... ( and not well locked )
I´ll check my RTB theese days for deoce vs. roll mode

[mikeselectricstuff]

I'd never expect decode to work in roll mode, just to stop til rill mode exited,and not break anything

[Rich@RohdeScopesUSA]

We just released an update to the firmware (V1.200) to fix a couple issues:

-For active high-voltage differential probes RT-ZHD as well as power rail probe RT-ZPR the zero offset of the probes was not corrected automatically by the instrument.
-Probe attenuation was lost after preset with active probes.
-In XY mode channel unit A was not considered for grid annotation in diagrams directly.

Firmware is available here:
https://www.rohde-schwarz.com/us/firmware/rtm3000/

Release notes here:
https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_firmware/pdf_3/RTM3000_Release_Notes_v01.200.pdf

-Rich

[Neganur]

That power rail probe (RT-ZPR) looks very similar to the one Keysight is selling, even the SMA-to-1:1 probe browser looks exactly like the ones PMK make for Keysight.

I wonder if PMK makes those power rail probes?

Very nice to see there's a 4 GHz version in addition to the 2 GHz version offered by R&S.

[Rich@RohdeScopesUSA]

That power rail probe (RT-ZPR) looks very similar to the one Keysight is selling, even the SMA-to-1:1 probe browser looks exactly like the ones PMK make for Keysight.

I wonder if PMK makes those power rail probes?

Very nice to see there's a 4 GHz version in addition to the 2 GHz version offered by R&S.

Hi Neganur - the probe itself is designed by us, in-house.  Some of the accessories might be sourced from a 3rd party (PMK would be likely).  The ZPR has four big benefits:

1.  Very low noise.  Combine this with a RTM/RTA/RTE or RTO (which are all very low in noise too) and it's great, low noise solution for measuring power rails so the scope/probe doesn't eat in to your tolerance.  Add to this full bandwidth at 1mV/div and up (most other scopes either BW limit or software zoom) and you can get a super accurate measurement of your DC power rail.
2.  +/-60V of offset.  It also has a built-in AC coupling mode (not available with Keysight).  In general, I recommend you still use the integrated offset so you can see drift over time or droop.
3.  High bandwidth with slow roll-off.  The ZPR20 (2GHz) can see coupling of a 2.4GHz signal - the amplitude won't be accurate, but just knowing you have coupling is helpful.  Same for the ZPR40 (4GHz) - it can see a 5GHz signal coupling in due to the Gaussian roll-off.
4.  Integrated Probemeter - it's a high(er) precision voltmeter built-in to the probe (uses its own ADC).  Very nice to quickly see the exact rail level so you can easily remove that offset.

It's not a probe for every measurement, but if you have to accurately measure your DC power rail, it is tough to beat.

-Rich