Anyone with R&S CRTU-RU experience? (WTF is this thing anyways...)

[mzzj]

I just bought 2 of these cheaply without exactly knowing are they any good for anything ?
Is it usefull as a general purpose spectrum analyzer and rf generator or something else usefull? Or did I just buy 2 subjects for teardown videos 

[TimFox]

When asking about an obscure device, it would be better to spell out the abbreviations.
I know "Rohde & Schwarz", but what does CRTU-RU spell out?  Is it on the panel?

[mzzj]

When asking about an obscure device, it would be better to spell out the abbreviations.
I know "Rohde & Schwarz", but what does CRTU-RU spell out?  Is it on the panel?

I know exactly as little  as you what does CRTU spell for 
"Universal Protocol Tester"
http://www.equipnet.com/auctions/rohde-and-schwarz-crtu-ru-universal-protocol-tester_listid_445615/

[TimFox]

I found the data sheet at this link:
http://www.mcs-testequipment.com/resources/Datasheets_Downloads/Rohde-Schwarz/CRTU%20Datasheet.PDF

[McBryce]

Here's a spec sheet: http://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/CRTU_specs_en.pdf

If you're into analysing 2G/3G networks then it's useful...

McBryce.

Edit: Oops, Tim was faster

[Wuerstchenhund]

I just bought 2 of these cheaply without exactly knowing are they any good for anything ?

Well, the CRTU is a cell phone production tester, predominantly meant for automated testing. So that's what it is good for.

Is it usefull as a general purpose spectrum analyzer and rf generator or something else usefull? Or did I just buy 2 subjects for teardown videos 

The CRTU uses the same modules as the R&S CMU200 (general purpose comms tester), and if I remember right it also supports the same basic functionality so you'd get a 100MHz to 2.7GHs Spectrum Analyzer, and depending on the options and activated licenses one or two RF generators, an audio generator and analyzer, and a Power Meter. However, (unlike the CMU200) the CRTU was made as an automated tester, so a lot depends on the activated software licenses on the particular unit.

BTW, should you consider selling one of these things then let me know (send me a PM). A CRTU would be a nice complement for my CMU200.

[mzzj]

Here's a spec sheet: http://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/CRTU_specs_en.pdf

If you're into analysing 2G/3G networks then it's useful...

McBryce.

Edit: Oops, Tim was faster

I was also able to find the basic datasheet but its kind of vague about how usefull this is for anything else than cellular 2G/3G stuff. A proper manual would be great.
Based on this http://www.helmut-singer.de/stock/-1871243771.html I am hopefully getting a RF signal generator and somehow usable spectrum analyzer.

Wuerstchenhund: Thats what I questimated based on the info that CRMU is somewhat newer version of the  CMU200. Feel free to make a reasonable offer after I fiqure out what options(if any) I have got in my units.

[Wuerstchenhund]

I was also able to find the basic datasheet but its kind of vague about how usefull this is for anything else than cellular 2G/3G stuff. A proper manual would be great.

For a lot of R&S kit getting manuals and software require an service account (GLORIS) with R&S unfortunately.

Based on this http://www.helmut-singer.de/stock/-1871243771.html I am hopefully getting a RF signal generator and somehow usable spectrum analyzer.

Typical HS, they're asking 10 EUR grand for it. I do wonder who actually pays their insane prices. Madness.

But hey, you could ask them if they buy yours for EUR8k. Must be a bargain for them 

Wuerstchenhund: Thats what I questimated based on the info that CRMU is somewhat newer version of the  CMU200.

Well, it isn't, really. Both CMU200 and CRTU were made for different purposes. The CMU200 was designed as an universal comms tester for various cell phone standards (GSM, CDMA, W-CDMA, UMTS/HSDPA, EV-DO) as well as Bluetooth, for both lab and production use, and also with general (non cell phone testing) applications in mind.

The CRTU on the other hand was designed as an automated test platform for cell phone production. While the CMU200 could be used for the same task, automated testing with the CMU200 requires an external computer as test controller. The CRTU doesn't as it comes with a built-in Windows2000 PC. On the other side, the CRTU is very limited in its capabilities, and doesn't support everything the CMU200 does.

There are various variants of the CRTU. In general, the -PU are the Protocol Analyzers (focussing on the logical level) and the -RU are the Radio Controllers (dealing with the RF part). The chassis is essentially the same as the CMU200 chassis, with the exception of the righthand front where the CMU200 has some Sub-D connectors and a speaker while the CRTU has three N connectors for the built-in power divider. There also are some differences on the rear connector panel.

The fact that the CRTU was primarily designed for automated cell phone testing shows in several areas (i.e. the CRTU can only act as a Base Station while the CMU can act as Base Station and as terminal/receiver). Also, for the CMU200, most optional functionality is enabled when the required hardware module is installed, while the CRTU requires additional software licenses. I'm not sure if this also affects the Basic Functionality (Spec An, RF generator etc), or if this functionality is even available in the CRTU. But I do know that the CRTU only supports a subset of functionality of the CMU200.

The original CMU200 (with FMR5 controller with AMD K5 processor and with PS/2 keyboard interface) was introduced in 1999 and the CRTU in 2002. Both were supported until around 2010 when they were replaced by the current CMW500.

Feel free to make a reasonable offer after I fiqure out what options(if any) I have got in my units.

Sure. Send me a PM over the forum when you get the units.

[mzzj]

https://groups.yahoo.com/neo/groups/Rohde_Schwarz/conversations/messages/407
"if you are limited in space consider the CRTU-RU, those units are part of a protocol analyzer System for GSM/WCDMA but contain a full featured spectrumanalyzer, a signal generator and powermeter from 10-2700MHz , the unit can "eat " up to 50W , the signal generator can output from
 -10 to -130dBm and offers AM and SSB modulation as well as frequency hopping !
 those units are recently hitting the surplus auctions for about $1000 or less and you can expect to see those on ebay soon !"

Oh boy, now I am exited   

[McBryce]

You know you're stuff about these Wuerstchenhund, I assume you work in this field or are you just a very enthusiastic collector?

McBryce.

[PA0PBZ]

SSB modulation on a cellphone tester? That just seems... weird 

[idpromnut]

We had a CMU-200 that had a dead screen; fixed it by replacing an inductor on the back-light power supply that had blown open.

[Neganur]

the crtu is supposedly a cmu with the added sig gen and spectrum analyser. I imagine it's the 'front end' of a signalling/physical layer testing system that can perform typical 2G/3G specification tests fully automatic (i.e. the signalling unit connected to the crtu is calling test sequences incorporated in the crtu). You can probably not use any of the test functions but it should be a very usable signal generator and basic spectrum analyser with specs good enough to demodulate the modern digital mobile communication standards, and with a little luck it will have an I/Q interface that can connect to other signal analysers.

I don't dare to guess about the spectrum analyser capability, usually they're quite tailored to the relevant frequency bands but wcdma etc use quite wide bandwidth, plus it's R&S so probably good quality.

EDIT: the few specs found in datasheets are nice, it has a good ocxo (as expected from base station quality instruments). Sig gen is 100 kHz-2.7GHz in 0.1 Hz steps and 400µs settling time for jumps of 1 kHz, nice output repeatability and level settling time.

[TimFox]

SSB modulation on a cellphone tester? That just seems... weird 

The original analog cellular telephones used SSB, which is generally the most bandwidth-efficient analog modulation.
The later protocols are digital.

[PA0PBZ]

SSB modulation on a cellphone tester? That just seems... weird 

The original analog cellular telephones used SSB, which is generally the most bandwidth-efficient analog modulation.
The later protocols are digital.

Really? Maybe in the US but I would be surprised. Here in EU I have never seen that, before we switched to GSM it was NBFM modulated.
Do you have any links to that?

[Mr Simpleton]

Had a quick look at the stuff from Nokia... and I guess those who are into RF in Finland had a blast...
Wish I have had a chance to bid, and pick up the stuff... I am sure with that volume of sales things were going really cheap!

[TimFox]

I stand corrected:  the original analog systems were FM.  However, SSB communication is used in other systems such as marine radio which might use this test equipment.

[mzzj]

I am sure with that volume of sales things were going really cheap!

Not really. See https://www.eevblog.com/forum/buysellwanted/auction-%28finland%29-rf-test-gear-end-of-march/ for comments.
Many items went skyrocket high prices like piece of crap old tektronics TDS220 scopes for 600 euros! Total madness. I wouldn't pay more than 60 euros for those 
Some RF stuff went for pocket change but anything known to be usefull was  expensive unless you were lucky with the buggy timeoutting POS auction website and others were not able to bid on your items when the server was overloaded 

CRTU-RU "mystery boxes" went for 50 to 200 euros per piece, time will tell if its expensive thursday teardown  or really cheap 2.7Ghz spectrum analyzer+rf generator

[mjs]

I got a few of the CRTUs from the lot. One will be experiencing a full teardown and the results will be posted here as soon as I get the victim in the lab!

[tmbinc]

He, seems eevblog bidfest was on the CRTU-RUs. I bought 8 of them (and accidentally a single -PU). (Stupid auctions all ended at the same time; paid between 42 and 104 EUR, but shipping will be another ~500 EUR total)

My hope is that I can get the I/Q output (CRTU-B7), but mine are apparently missing the option for it. I wonder what else the output to the PU is, if not I/Q. Does someone know? Is it a non-zero IF instead? Also, what's the bandwidth for the RX and TX path?

If the hardware does what it promises, I'm good. If the default software doesn't do it - I'm sure we can get enough critical mass here to maybe develop a custom software for it ("how hard can it be" - famous last words) that is more hacker-friendly.

[Wuerstchenhund]

If the hardware does what it promises, I'm good. If the default software doesn't do it - I'm sure we can get enough critical mass here to maybe develop a custom software for it ("how hard can it be" - famous last words) that is more hacker-friendly.

Good luck with that. If I remember right the basic software runs on MsDOS 6.22 (yes, really!), the Windows part is only for automated testing. And even the DOS software doesn't do much as all functionality sits in proprietary custom DSPs with R&S IP in their cores.

I also wouldn't count on R&S just sitting there and observing any hacking attemps like Rigol and Siglent.

If you want a cheap hack-able Spectrum Analyzer/Signal Generator/Network Analyzer then have a look at the Agilent E7495A/B which runs Linux. Does less in terms of cell phone testing but the Spectrum Analyzer is better than the one in the R&S CRTU, and the Network Analyzer part isn't bad, too.

[KJDS]

There's a chart of differing cellphone standards here

http://www.rfcafe.com/references/electrical/wireless-comm-specs.htm

Unfortunately the only main thing missing is the modulation scheme, however I'm fairly certain that AMPS, the American Mobile Phone Standard used FM.

[McBryce]

I also wouldn't count on R&S just sitting there and observing any hacking attemps like Rigol and Siglent.

It's a 2G/3G test device, more or less passed it's sell-by-date, I doubt R&S really care that much unless of course their current products use the same modules and would be also instantly hackable with the same method.

McBryce.

[dom0]

R&S support is generally very friendly and helpful and even helps buyers of second hand gear, hams and so on (R&S is most certainly NOT part of the Servicewüste Deutschland [service wasteland Germany]). So there might be a chance that they unlock certain software features for you...

[Wuerstchenhund]

I also wouldn't count on R&S just sitting there and observing any hacking attemps like Rigol and Siglent.

It's a 2G/3G test device, more or less passed it's sell-by-date, I doubt R&S really care that much unless of course their current products use the same modules and would be also instantly hackable with the same method.

As both CRTU and CMU200 are still supported and updates/licenses are still sold I'm pretty sure R&S will care. The CRTU isn't that attractive but the CMU200s are still widely used and in demand, especially with the W-CDMA/HSDPA/HSUPA and Bluetooth options and the High Stability Reference OXCO (option -B12).

You'll find that the CMU200 (along with Agilent's E5515C/E) is still the to-go tester in lots of labs world-wide for everything cell phone related which isn't 4G. It's only now that they start to appear on the second hand market in larger numbers, but most of these units are the older (1st gen with FMR5 controller and PS/2 keyboard port) ones which usually only come with basic GSM or CDMA. Getting a second gen CMU200 (with FMR6 controller with Celeron and USB ports) with W-CDMA/HSDPA/HSUPA, Bluetooth and -B12 OCXO can still set you back >$10k.

R&S support is generally very friendly and helpful and even helps buyers of second hand gear, hams and so on (R&S is most certainly NOT part of the Servicewüste Deutschland [service wasteland Germany]). So there might be a chance that they unlock certain software features for you...

Yes, for gear that is no longer supported. I wouldn't bet on that they are so forthcoming for kit that is still supported and for which upgrades and software are still sold. Attitudes change quickly when it affects the bottom line.

BTW, I checked R&S GLORIS, and unlike for the CMU200 (for which software updates and manuals are available) there doesn't seem to be anything for the CRTU. WHich, considering that the CRTU was sold as a complete test solution and not as individual instrument, isn't surprising.