Rohde & Schwarz SML Series Signal Generators - SML01 SML02 SML03 SMV03 - Page 1
Forum section: electronics / testgear

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 04, 2025, 10:57:35 pm
content: This weekend I got an R&S SML03 to play with. So far, I like it:I cleaned it up a bit, and it looks a lot nicer now. I opened it up and dusted it with some compressed air, and attacked the fan also. That helped reduce the fan noise a little, but it's still a loud ass fan.Signal quality looks good, and it's pretty darn close considering it hasn't been calibrated since March of 2007. A 500MHz signal shows 499.9995MHz on my SDS2504X HD. 100MHz shows as 99.99990MHz. 10MHz shows as 9.999989MHz, which is about what the internal reference showed over an extended period of time. I may try to do a small adjustment.Here's some useful info for the series:Stock Fan: 622N EBM-PAPST12V DC, 160mA (SML service manual specifies 12V, 170mA max)Passwords (use at your own risk):LEVEL 1 Password: 123456LEVEL 2 Password: 261339LEVEL 3 Password: 710845LEVEL 4 Password: 593748From the manual:QuoteETA: I've attached the final firmware version 2.51.15 (with permission) for the SML series. USE AT YOUR OWN RISK!!! It requires a 32bit Windows version to be installed. It took 24 minutes to install for me.ETA2: Power supply modelLPQ154datasheet added.ETA3: Maintenance manual section including error codes added.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 04, 2025, 11:00:35 pm
content: The only defect thus far appears to be a couple horizontal lines that aren't supposed to be there. This appears to be common with these.Anybody know any tricks to fix those lines without replacing the screen?I don't know what causes them, but there's a 3rd line that only appears occasionally, and I haven't seen it yet since dusting this thing.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 04, 2025, 11:24:30 pm
content: I'm not a fan of the stock fan, and I'm considering replacing it. It's a simple two wire connection.Here's the specs:Stock Fan:622N EBM-PAPST12V DC, 160mA (SML service manual specifies 12V, 170mA max)Operating voltage: 8-15V DCFan dimensions: 60x60x25mmFan efficiency: 40m³/h (~23.5CFM)Noise level: 35dBARotational rate/speed: 6100rpmhttps://www.ebmpapst.com/us/en/products/compact-fans/axial-compact-fans/p/622N.htmlWhat do you think about their air performance curve chart? I wish it specified the voltages on the chart too. Is 40m³/h happening at 12V or 15V?I was thinking about using this as a replacement:Noctua NF-A6x25 FLX12V DC, 80mAOperating voltage: 12V DCFan dimensions: 60x60x25mmSpeed: 3000 RPMAirflow: 29.2 m³/h (~17.7CFM)Noise level: 19.3 dBAThe CFM difference is less than 6. Is 6CFM enough to worry about? The significant noise drop would be nice.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 04, 2025, 11:39:05 pm
content: I think it's cool that the SML can dotwothree modulations at once.Here's a 500MHz sine:Here it is with FM modulation:Here it is with AM modulation:Here it is with both:Thanks,Josh

author: tautech
author_rank: Super Contributor
timestamp: May 05, 2025, 01:24:56 am
content: Amplitudemodulationsweep too ?SSG3021X can do and you can set up some eye catching effects for exhibitions.You have to do a video to really show that effect.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 01:45:23 am
content: Quote from: tautech on May 05, 2025, 01:24:56 amI'd love an SSG3021X. Send me one! 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 01:47:13 am
content: Holy Shit, Batman! I love how easy it was to adjust the calibration with this. 🤯You activate the Adjustment State by setting it on, and then modify the Frequency Adjust setting. That's it. It was set to zero. I connected it to the counter on my SDG2122X and adjusted it there:Now the waveform counters are all spot on:Adjusted reference output from SML03:10MHz RF Output:500MHz RF Output:Thanks,Josh

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 05, 2025, 04:14:27 am
content: HI,try to install an original fan or at least a fan with the same values.The R&S devices get very warm internally, the Noctua fans are nowhere near the static pressure.The components usually die slowly due to the heat (in my experience)You can also look at Sanyo Denki, they also make good fans.I like to use them and if possible with more thickness, they can build up more pressure with the same noise.the SSG3021x have a bad phase noise and only go down to -110dbm level, the SML goes down to -140dbm, the phase noise is ok so far, not high end, but normal for the class. (this was/is the “beginner low budget” class)If you can find the calibration software (service kit) somewhere, I would be grateful if you could pass it on.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 05:33:10 am
content: There's a 25% difference in airflow between the two fans at their stated specs. I'm curious what the stock fan actually runs at though, since it states operating voltage up to 15VDC, and the SML runs it at 12V. I might try a photo tachometer or stroboscope or something to see what the real RPMs of the stock fan are.Regarding static pressure, I don't really understand that part too well, and the actual airflow/RPMs are still in question with the stock fan. So here's my question: what's the real difference? Stock fan air performance chart says at 30 m³/h, static pressure is under 0.1in H₂O. The internet supplied conversion chart says that's a little bit over 2mm H₂O. The Noctua fan is rated 2.18 mm H₂O at 12V. Seems close to me?Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: May 05, 2025, 04:21:11 pm
content: Hi,I am responding to this post here because it fits better here.https://www.eevblog.com/forum/testgear/siglent-sds2000x-hd-12bit-(published-for-chinese-domestic-market-only)/msg5904862/#msg5904862QuotePhew...Is there another filter active, do you have another filter in between?There should be a self-test, what does it say?Which output are you connected to?

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 05:19:21 pm
content: Quote from: Martin72 on May 05, 2025, 04:21:11 pmI'm not using any filters, or terminators. 50Ω termination is set in the scope as usual. The SML03 has auto level correction (called ALC in the menu system).It's my understanding that ALC is supposed to apply the calibration settings for different ranges. It makes little to no difference whether this setting is on or not. Turning off ALC gives the option of either applying a correction Table, or Sample&Hold. Neither improved the level in any interesting kind of way.ETA: There is an Attenuator listed in the settings. That is either set to auto or fixed range, and the fixed range is preset and can't be edited. Neither option does anything when tested at a fixed frequency.There is a Ucor (User Correction) setting I want to try out, but I need to be able to accurately measure and correct this at least up to 1GHz for it to be meaningful for the bw test. I obviously can't do that with my 500MHz scope. So how can I test this accurately? My DAQ6510 seems to be the best option, but I'm not sure if that's sufficient either. Do I need a power meter?Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: May 05, 2025, 05:40:23 pm
content: Hi,QuoteIts bandwidth will not be sufficient for this."Unfortunately", my SML had been functioning properly in this regard, so I am unable to offer any additional assistance beyond general tips such as using the correct output (RF not LF, then switch on RF in the menu as well) and performing a factory reset.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 05:53:19 pm
content: Quote from: Martin72 on May 05, 2025, 05:40:23 pmThat's what I figured regarding the DAQ. I'm not sure what power meter would be sufficient, but maybe I'll attack eBay...or see how much cal/adjustment would cost.The LF output is DDS that only goes up to 1MHz. I've also done a factory reset.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 05, 2025, 11:45:20 pm
content: With the output level set to +5 dBm, this is what it looks like on my scope. A level adjustment should take care of things nicely. Last calibration was in 2007, so there's that.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 12:13:11 am
content: Interesting! I found the level calibration list that was in use. That's exactly what the problem is. The Level cal table is 18 years old, and the values are stupid. 🤣

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 06:39:35 am
content: I got the last firmware installed (was 3 versions behind), but it's a 16bit app with a 32bit installer. So WineVDM was useless (it can theoretically run the 16bit app, but can't touch the 32bit installer). I had to find an app to install 32bit Windows on an external drive so I could run it from my wife's old laptop that I'm not allowed to format.It took 24 minutes to update the firmware, which was hilarious because the SML says FASTLOAD on the screen the whole time. I don't want to know how long SLOWLOAD would have taken! It's a good thing I'm patient sometimes in my old age. 😉Thanks,Josh

author: pdenisowski
author_rank: Super Contributor
timestamp: May 06, 2025, 10:33:13 am
content: Quote from: KungFuJosh on May 06, 2025, 06:39:35 am

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 03:50:23 pm
content: After running the firmware install, the internal calibrations were cleared (as expected). What's interesting is that in clearing those level lists, it's already a lot closer to 0dBm, and more linear...except for a few frequencies that put out nothing. 🤔I haven't run the auto calibrations yet; I'll do that soon.Right now, I've unlocked Level 2 so I can do the 10MHz ref calibration (without using the user override option). The SML warmed up for over an hour, and it seems stable enough.Final firmware added to OP.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 04:11:46 pm
content: Well, that worked!After installing the new firmware, calibrations cleared, ref adjusted, then running calibrate all- it's MUCH better.It's pretty stable at 220mV (within -1mV) from 9kHz all the way to 100MHz. Then it drops as follows:200MHz 213mV300MHz 201mV400MHz 191mV500MHz 176mV600MHz 136mVI don't have a proper RF power meter to determine whether that's the scope's limitations or the sig gen, but I assume the former or a combo of both. I might need to get me an RF power meter now lol.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: May 06, 2025, 04:19:01 pm
content: Hi,Congrats...Now do a sweep....By the way:QuoteThat could be right; the -3dB point of the scope is somewhere between the two frequencies.Taking 220mV as a basis, that would be 220mV* 0.707, or approximately 155.5 mV.

author: Grandchuck
author_rank: Super Contributor
timestamp: May 06, 2025, 04:21:46 pm
content: Have you tried other coax cables ... I find they vary some at the higher frequencies.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 04:35:28 pm
content: Quote from: Martin72 on May 06, 2025, 04:19:01 pmThanks! It's running now. 😉QuoteThat's what I assumed...and why I put an offer on an RF power meter. 😉😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 04:38:41 pm
content: Quote from: Grandchuck on May 06, 2025, 04:21:46 pmRight now I'm using an RG316 BNC cable with a type N to BNC adapter. I'll also try a cable that's coming this week that's RG142 type N to BNC (no need for adapter), and I'll try an RG58 BNC cable with the N to BNC adapter.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 06, 2025, 04:58:05 pm
content: Quote from: KungFuJosh on May 05, 2025, 05:33:10 amDoes anybody else have any thoughts on this? I have an RPM tester coming today. I'll see how fast the stock fan is actually running.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 07, 2025, 10:44:11 pm
content: Stability of the internal ref seems okay.ETA: Updated photo.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 08, 2025, 04:39:30 am
content: I think this is the first time I've ever used the TinySA for something besides it's signal generator. 🤔

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 08, 2025, 06:16:14 pm
content: Well, I answered my own question about fan speeds. See attached.At 12V, the stock fan is indeed twice as fast.At 15V Noctua goes up to ~3558, which the stock fan beats at 8V.So which one cools more efficiently?According to my thermal camera, the peak temperature was 100F with the stock fan after hours of running. Currently, the Noctua is holding around 97F after a little over an hour. I'll update in a few hours to see how it looks with the thermal images.The Noctua fan does not sound half as loud. I might use a dB meter app on my phone to compare, but we'll see. It sounds smoother for sure, but the overall volume change isn't amazing.Thanks,JoshETA: I tried two different apps on my phone, and both say the fans are about the same dB level. The stock fan has a higher pitch noise, that is more annoying than the Noctua fan, but they're definitely close in volume level either way. The Noctua fan has the softer/consistent Noctua sound, but is louder than I expected it to be.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 08, 2025, 11:22:26 pm
content: Final verdict: Not worth the hassle, general waste of time...but still entertaining.The pitch of the stock fan is slightly higher, but overall seems quieter, despite the piece of crap sound meter app I downloaded thinking they're the same level. I measured both fans in and out of the SML.Difference in temperature performance is also nothing special in either direction. Max temp with the stock fan was 100.4F, and it was within half a degree over a 5 hour period with the Noctua fan.I wonder if the voltage of the fan is regulated based on internal temp? That could explain why the Noctua was louder than expected if it was running higher voltage to make up for the temp difference. 🤷

author: pdenisowski
author_rank: Super Contributor
timestamp: May 12, 2025, 12:22:02 pm
content: Quote from: KungFuJosh on May 08, 2025, 06:16:14 pmIf you wait long enough, higher pitch noises won't annoy you nearly as much as they do nowThanks for all the great write-ups!

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 03:51:21 pm
content: Quote from: pdenisowski on May 12, 2025, 12:22:02 pmI got another SML03, and the stock fan is much better; quieter and no high-pitch noise. So it looks like replacing with a new stock model fan is the best option (besides getting older faster). 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 03:55:55 pm
content: Here's a couple photos of another SML03 I got this weekend. This one has the B1 OCXO and B3 Pulse Modulator options.It also has a defective output unit. I put the output unit from my other SML03 in it, and it worked (then I put the original back in). I'm suspicious there might be something wrong with the B3 module also, but I will figure that out later.If you're looking for an SML, pay attention to the photos. I've seen some advertised as having options that were clearly not installed.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 04:00:59 pm
content: Here are some photos of the allegedly defective output unit. Nothing jumped out at me for obvious issues.

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2025, 04:17:28 pm
content: Is the red circle the output?Then it should be some kind of relay.The yellow mark looks like a suspicious solder joint.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 04:36:06 pm
content: Quote from: Martin72 on May 12, 2025, 04:17:28 pmGood eye. Yes, that's the output, and it does look like a broken solder joint in the photo. I hope it is! I just reviewed the microscope video I made looking over the board, and that's the one spot I missed. 🤦The reason I say I hope it is, besides being an easy fix, is that the coating they put on isn't smooth and creates misleading shadows.Time to disassemble again. 😉Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2025, 04:45:03 pm
content: I don't know if you can access it while it's running, but you could measure at the input of the “relais” to see if the set signal is still arriving correctly.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 05:27:22 pm
content: Quote from: Martin72 on May 12, 2025, 04:45:03 pmIt was the ugliest solder joint for sure, but it didn't look broken from other angles. I cleaned it up and resoldered it anyway.The writing on the part didn't bring anything up for replacement. 5000-0266 C0T0-0815 M? Anybody know what this is?ETA: My uneducated guess is that this is the only mechanical part on the output unit, and the most likely thing to die without any signs of stress. Despite looking much nicer/newer than the other unit, this one has currently 4410 hours of use.

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2025, 08:11:02 pm
content: That's still brand new; my SML01 had over 100,000 hours on it.(No joke)

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 08:33:46 pm
content: Quote from: Martin72 on May 12, 2025, 08:11:02 pmGood to know! 😉I've decided to sacrifice parts from the 1st unit for the 2nd one. I can worry about fixing the 1st one or sell it for parts later.

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2025, 08:55:41 pm
content: Either way, you would then have an SML03 with OCXO reference that looks almost new and has very few operating hours, which is pretty cool....

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 09:06:15 pm
content: Exactly. I already swapped it, and it's warming up now so I can calibrate it again (I pulled the battery to force recalibration and wipe the old data).Before calibration, it outputs 100MHz as ~102.4MHz. After cal, it will show 100.0000MHz on the scope.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2025, 08:54:03 pm
content: I've got the mix of parts in unit 2 now, and it's working great. However, I needed to remove the SML-B3 option (pulse modulation).I haven't popped the B3 open yet, but something is wrong with it. After running the self calibration with B3 present, the output is too high. After correction, the output is still nearly 50mV too high. Removing the B3 and changing nothing else (not even recalibrating) puts the output damn close to 0dBm at ~222mV. The signal is also cleaner (mostly seems to affect lower range).Any ideas what would cause this issue with the SML-B3 module?Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 14, 2025, 02:45:24 am
content: Here's what the SML-B3 option unit looks like.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 14, 2025, 02:57:15 am
content: Just for fun, here are some photos of the PSU.

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 15, 2025, 03:49:47 am
content: Hi, sorry I haven't spoken for a long time.As far as the pressure static of fans is concerned, there are usually diagrams that show the capacity of the fans and are not linear.I have noticed that the Noctua fans react badly to high restriction, they get loud and the pressure drops sharply.Regarding your SML03 and B3, the installation and conversion to B3 requires a factory calibration, as the module is installed in the RF signal path. (Service KIT software + NRVD + Z51)This is why your levels are not correct.Better repair the 3Ghz module, I think what you have marked is the RF coupler for the ALC.The used switches 4227T have errors, replacement is very expensive, an exchange to HMC types is conceivable, work on it again entails a service kit calibration.Unfortunately, even R&S no longer seem to have this software, at least here in Germany...Servicemanual:https://manuals.repeater-builder.com/te-files/R&S/R&S%20SML_SHB_BD2_03%20Service%20part%202.pdf

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 15, 2025, 04:05:53 am
content: Quote from: KeBeNe on May 15, 2025, 03:49:47 amYou were right anyway. I posted my results above- the Noctua lost. My second SML03's stock fan is much quieter, and not an issue.QuoteThat's odd. The B3 came with the SML03 as a preinstalled option along with B1. I swapped mainboards, and I think the B3 was tamer with the one that was not calibrated for it.Do you know if there's something in the mainboard that needs to be unlocked for the B3 to be used? I haven't tried the original mainboard yet, but with the replacement board, it said something about it not being available despite it being connected. I was hoping it would sense it like it does with the B1.QuoteI don't know which part or photo you're referring to? Do you mean the part I have marked as Main Output Unit (which I think is actually an attenuator)?Quote4227T sop8 appears to be available at aliexpress, but blocked to the US right now. It's okay; I swapped the attenuator out from the other unit, and it's fine. I'm going to sell the other unit (for parts or repair), and somebody else can fix that if they want it to work.Your input and help is much appreciated!Thanks,Josh

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 16, 2025, 02:29:37 pm
content: Hi,If I understand you correctly, you have exchanged the mainboards, as the factory calibration is stored on the mainboard, in the flash, in the protected area, a factory calibration is required.What I mean by this is that the mainboard with all the assemblies connected in RF path is a calibrated chain, if you dissolve it, it is good luck that it has the correct levels afterwards.How are the levels measured?Do you have a spectrum analyzer which is still accurate?Measuring the values with an oscilloscope is one of those things, as the input of the oscilloscope can also have a mismatch.The measurements are not optimal and you need more accurate measuring devices than an oscilloscope to test these measuring devices.Regarding the options, I have never had an SML, but it may be a similar procedure to the SMT/SME/SMIQ, i.e. the modulation type is activated with a key.You can look in the menu to see if they have the item "installation", this is for installing options, these can be entered by deactivating Protect Level 2, at least with the big brothers.It would be interesting for me to know whether an SML02 can be turned into an SML03 using a factory key.With the SMIQ02B and SMIQ04B you "only" need a factory key for the 3Ghz or 6Ghz version to turn an 02B into an 03B and an 04B into an 06B.I have edited your picture to explain the modules, the OPU1 is on the mainboard, the OPU2 is the doppler/trippler module.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 12:33:05 am
content: Quote from: KeBeNe on May 16, 2025, 02:29:37 pmThe SML series does a self calibration to determine levels. It generally works quite well, but not when the B3 module is installed. The mainboard sets the correct levels, but the B3 boosts what is actually outputted.QuoteMeasured on:SDS2504X HD oscilloscopeTinySA UltraKeysight V3500A RF Power MeterAll devices are agreeable (TinySA required minor level adjustment at 1st frequency, then matches levels across the range within reason given its limitations).QuoteThere's nothing in the service manual about installing anything except hardware. Hardware is detected when its installed, and the options for it appear on screen. I'm going to swap mainboards back again to experiment with the B3 module.For example- either mainboard ignores the OCXO if not installed. Either motherboard also gives an oven cold warning on startup when the OCXO is installed.Either mainboard doesn't have any pulse options on screen when the B3 module isn't installed. The Pulse menu appears when B3 hardware is installed.QuoteI have no idea on this one. The module says 2/3GHz. It would be funny if there's something like a jumper hiding in there to limit the module.QuoteThanks. I labeled "main output unit" that way because that's how it's labeled in the service manual. The attenuator is just a part of it. Though you're right, it probably is the hard to find switches that need to be replaced in the defective unit.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 03:23:59 am
content: Here's some examples. The only changes are the hardware attached.1st Unit (didn't come with B1 or B3 options) with B1 OCXO connected:B3 hardware not installed:B3 hardware installed:Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 04:23:42 am
content: I just put unit 2 back together with unit 2 parts except for the main output module, and 2/3GHz module from unit 1. B3 is installed. It's not warmed up yet, but output is now showing slightly under 0dB rather than being high.All I did was clean it a little more, and wiggle connections. I bet that wiggling helped. 🤔I'll let it warm up, and test the levels again. If it's still low, I'll run the self calibration and see how it looks. Hopefully, running calibration doesn't mess it up.Update:Warmed up, and ran 'Calibrate all' again.-0.49dB at 10MHz through 500MHz, -0.75dB at 1GHz, -1.5dB at 3GHz using the V3500A power meter.That's dead on with the scope showing 211mVrms at 10MHz:That must have been some special wire wiggling. 🤷Thanks,Josh

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 17, 2025, 05:20:53 am
content: Please look under utilities, there you will find the item Install for SME and SMIQ.Yes, if you install the B1, you do not need a key, this is the case for all devices, but it is for PM, even if the HW is installed, for the other RF generators this is the option B11(HW). this also includes software keys.Calibration, the self-calibration has nothing to do with the factory calibration.The factory calibration is carried out over the entire RF chain and sets a reference point; this reference point is used as the target for the user calibration.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 05:36:08 am
content: Quote from: KeBeNe on May 17, 2025, 05:20:53 amThis is the SML. There is no item Install anywhere on any of the menus. At least not that I could find. See attached. Maybe a hidden menu? That is possible, but doesn't seem likely. Maybe it's related to passwords 3 and 4 that they don't give us any details about. Still seems unlikely though since B3 showed up on the other mainboard.QuoteB3 PM module shows up on either mainboard. It gave an error once on the mainboard that didn't come with it, but that was more likely me doing weird settings (or an issue with the hardware?). It shouldn't have shown up, or allowed me to do anything if an install key was needed. I could be wrong, I dunno. I'm not plugging back in the other mainboard to find out at this point. 🤷 I will eventually screw around with the B3 module and see if I get that same error again.QuoteYes, I understand that. The self-calibration does what it's supposed to do, and corrects the levels, among all the other cal stuff it does. It's a great feature so that you don't have to ship it out to a cal lab every 3 months. 😉Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 03:12:06 pm
content: I was able to recreate the error with the motherboard that came with the B3 option. It's odd. The Pulse mod comes up in the menu, but it doesn't seem to do anything.Pulse Period, Width, and Delay all say Option Absent.Selecting one of them shows "parameter not available."But then it shows the current frequency there for some reason. Maybe a 20 year old bug?Then when I turned on the Double Pulse State option, it gave the error (same as other mainboard).So I restarted the SML holding down the 1 key (which seems to clear errors), now the options for Pulse show up, and can be edited without issue.I set the values randomly and pretty high, so now when I turn on Double Pulse State I get an error.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 04:00:00 pm
content: I RTFM and it didn't help.Thankfully, Paul has an awesome video (as usual):This one too:video(embedding is disabled in that one).Now I understand it a little better, and got rid of the error.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 04:22:05 pm
content: Aaaaaaaaaaaand the Pulse generator works fine...now that I know how to use it. 🤣Thanks for the awesome videos, Paul!

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 10:40:04 pm
content: Well, I got a 3rd one. 🤷🤣This one had a dead screen, so I took the screen from unit 1, and poof, it's awesome. I think this one was more recently calibrated than the other 2 units.I'm going to sell this one, and unit 1 for parts and keep unit 2 with the B1/B3 options. Or maybe keep this, and just sell the parts unit. 🤔 TEAS is real.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2025, 11:12:02 pm
content: I dunno if this is helpful / useful to anybody, but, here's a few images of what the firmware update process looks like. This other unit was faster by a whopping 19 seconds!I also grabbed the temp folder from the firmware updater app. Might be easier to update on a modern computer that way. 🤷

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 18, 2025, 04:07:31 am
content: Hi,As I said, I don't have an SML.But you have re-initialized the device, which must have re-read the assemblies, good advice, maybe I will come across an SML03 at a reasonable price.I look forward to hearing more about your experiences.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 18, 2025, 04:46:45 am
content: Quote from: KeBeNe on May 18, 2025, 04:07:31 amRegardless, your input is appreciated! I think you'll like the SML if you find a good deal. It seems good at what it does.Despite its large footprint, I also like the design choices R&S made. The footprint was obviously to make it fit in a rack. The modular design and layout of everything is brilliant. It still stands up pretty well 20 years later.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 19, 2025, 03:27:15 am
content: Yesterday I was playing with the pulse generator "video out" which directly outputs the set pulse. Today, I played with the pulse modulation.It gets weirder when you combine Pulse + AM + FM modulation.Messing with these settings also helped improve my triggering skills, which was a nice bonus. 😉Thanks,Josh

author: tautech
author_rank: Super Contributor
timestamp: May 19, 2025, 03:44:38 am
content: Quote from: KungFuJosh on May 19, 2025, 03:27:15 am1st grade simple stuff !When you need a Zone triggeror2 things are really getting interesting.....

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 19, 2025, 12:21:01 pm
content: Quote from: tautech on May 19, 2025, 03:44:38 amIf you knew what I was actually referring to, you'd call it kindergarten. 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 19, 2025, 10:08:08 pm
content: Is it correct that those RF switches marked 4227T are actually SSW-124?

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 20, 2025, 03:37:32 am
content: More modulation fun.SML03 settings:100kHz -10dBmAM Modulation: 80%Phase Modulation: 1.800 radLFGen Freq: 100Hz

author: KeBeNe
author_rank: Regular Contributor
timestamp: May 21, 2025, 02:46:09 am
content: Hi,Yes, that is correct.You can check if the switching voltage is +/-6V, R&S has sometimes operated them with up to +/-8V to improve the isolation, which is outside the specifications.An exchange for HMC270 would be conceivable, but you would then need the calibration software

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 21, 2025, 03:10:55 am
content: Quote from: KeBeNe on May 21, 2025, 02:46:09 amI found a source for the 124s, but they're $6 a piece...which isn't terribly terrible.I might experiment with the parts unit with the dead output module (attenuator).That calibration software doesn't seem to exist anymore. I really hope somebody finds it and shares it with us...but I won't hold my breath. 😉Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 02:21:46 am
content: Should I be concerned about this intensity fluctuation at all? Do I need to improve filtering or something in the SML? I see similar movement from the SDG, but the intensity color grading is generally consistent.

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 03:02:04 am
content: you can check SML output with some spectrum analyser to see if there isnt something faint coming out or some tiny instability of main frequency

author: pdenisowski
author_rank: Super Contributor
timestamp: May 23, 2025, 10:25:06 am
content: Quote from: kmoonwalker on May 23, 2025, 03:02:04 amAgreed. Does the scope have an FFT?

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 12:08:02 pm
content: Of course! Siglent has a good FFT, far better than my skills of utilizing it.Great ideas, thanks. Now to figure out the test setup, and avoid temptation to buy better SA... 🤔

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 01:58:18 pm
content: How's this look? Did I set it up correctly?SML03:SDG2122 for comparison:Thanks,Josh

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 02:02:02 pm
content: hmm you written some time ago about it being able to modulate the waveform etc - did you disabled all tricks from settings after playing with fancy signals?other than that something maybe broken (or cable or something on signal path is not good enough and scope reacts to that)also thing that I noticed (but it maybe due to not some huuge signal amplitude and scope approximation) - the amplitude is fluctuating a bit - from my university time old Rohde generator was so steady we tested all new ones against it and they usually failed ^^

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 04:15:06 pm
content: Quote from: kmoonwalker on May 23, 2025, 02:02:02 pm😉QuoteI think you hit the answer right there. I connected both gens with 50MHz 0dBm signals to my scope. Look at the Vrms stats, that looks pretty clear. A small difference, but a noticeable one, and not in the direction your experience would suggest.It's probably obvious from this conversation that C1 is the SML03, and C3 is the SDG2122X.Now, the question is, how can I stabilize that voltage further?Thanks,Josh

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 04:21:47 pm
content: now this is more like Rohde I remember - glad you have it pinpointedI did asked about setting due to fact that often with layered menu we do not see everything like on old equipment with knobs etc on front panel so check was a quick look - nowadays it is a good practice to twice/triple check everything in case of crucial measurements with expected result

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 04:30:02 pm
content: I would need to dig into complete specs of that generator but keep in mind that there are several factors:- not so big amplitude of signal so lot of things can impact it and will impact it- results are calculated so oscilloscope noise may play bigger impact than one could think for result- scope has limitations on approximation and thus calculations- your cabling may receive something even from your body, some EM, etc- something maybe coming thru filtering of generator/scope both from mains...Generator is old so filtering in PSU maybe maybe not great nowadays (but it should).There is some crosstalk between scope channels - you have some 2000x HD model if I remember correctly so it has a nice dampening compared to most but this can also play a factor in some cases.There is a reason why we use one and "best" channel in scope in a room with stabilized mains power, controlled EM etc to make small values measurements (thou usually smaller than this)but with this we are getting into metrology area with all its oddities, fancies etc and sometimes the question is if you really wanna know or can achieve itYou may also develop an sickness/need for top notch equipment just to be satisfied but it may not play a role at all on daily tasks.For example I would not have paid any attention to such small variation on my old 1054Z that I use for usuall stuff and it is more than enough for it - but its resolution is to small to see things. If I would shown you side by side for example HD314MSO with 14bits we could estimate which scope does a better job or second unit like yours to see if this is an expected behaviour for this ADC and maths conversion. Thing is that you have a very nice scope but diggin too much you may stop liking it. This applies to every scope on planet if you find a proper angle

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 04:52:41 pm
content: Quote from: kmoonwalker on May 23, 2025, 04:30:02 pmM&P connectors and Hyperflex 5 cable used for the tests.The scope's voltages, etc. have all been accurate, and in agreement with the V3500A RF power meter.I tried two different PSUs, and that didn't affect the fluctuation at all. Both looked generally the same, though were also around the same age.QuoteAll tests prior to the Vrms comparison were done on C1 with nothing else plugged in. The Vrms comparison test is using C1 and C3 as they don't share the front end toys.QuoteLet's stay just shy of that rabbit hole. 😉Thanks,JoshPS. You can see in the attached image that it's very clear on this series when modulation is active. It shows that modulation is on, and which types are active (up to 3 at once).

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 06:15:17 pm
content: I think it was the cable after all. I think there might be an issue with the shielding on the cable I was using.I made a shorter hyperflex 5 cable, and the voltage fluctuation is gone, and the consistency of the color grading is much more stable.

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 06:18:20 pm
content: the higher the freq -> more problems with everything which was supposedly good - now you have a scope that you can see literally everything instantly is something is wrong/off - congrats

author: Martin72
author_rank: Super Contributor
timestamp: May 23, 2025, 08:40:23 pm
content: Quote from: KungFuJosh on May 23, 2025, 01:58:18 pmI recreated this earlier.Source SDG6052X, Scope SDS3104X HD, Magnova BMO350.Coefficients for siglent Hamming and Hann, for Magnova Hamming.

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 09:04:53 pm
content: Hi, do you have similar noise floor without averaging on SDS3000?Both look way better than on Josh setup so I wonder if his hoise floor is impacted externally or this is the difference between 2000 and 3000 series

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2025, 09:14:56 pm
content: Quote from: kmoonwalker on May 23, 2025, 09:04:53 pmMaybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 09:20:33 pm
content: Quote from: tautech on May 23, 2025, 09:14:56 pmas you can see on pictures posted by Martin - two first are from Josh and later ones from Martin settings looks same for Siglent just Martin used averaging - anyway they have at least 10 dBm noise floor difference which makes me wonder if there isnt really something that Josh could improve on his setupor 3000 series really has such better dynamic range for fft

author: Martin72
author_rank: Super Contributor
timestamp: May 23, 2025, 09:28:21 pm
content: Quote from: tautech on May 23, 2025, 09:14:56 pmExcept for the averaging, I followed Josh's settings, which he shared in the post I quoted(picture).

author: egonotto
author_rank: Super Contributor
timestamp: May 23, 2025, 09:30:08 pm
content: Hello,Martin uses 65536 samples while Josh only uses 16384 samples.Best regardsegonotto

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2025, 09:34:51 pm
content: Quote from: kmoonwalker on May 23, 2025, 09:20:33 pmA Peak Hold setting might account for that.Without a Menu showing how might anyone know ?

author: Martin72
author_rank: Super Contributor
timestamp: May 23, 2025, 09:37:02 pm
content: @egonotto:My scope has twice the sample rate with the same time base.I followed Josh's post, where he took the measurement at 2 µs/div, not the one I´ve quoted before, sorry.Then he has 32k points and I have 65k.https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5923934/#msg5923934

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 09:37:44 pm
content: yep but samples amount should not impact the noise floor level - just better representationI think we need to wait for Josh to share a pic with full scale alike Martin shared cause he cutted bottom part on pics after cable repair.Also there the fall towards noise floor looks closer to Martins current results so maybe that fixed it for him, tooI am curious also due to fact I am considering to purchase some scope and such comparison (expecially with Magnova added) is very nice to see

author: Martin72
author_rank: Super Contributor
timestamp: May 23, 2025, 09:39:57 pm
content: Quote from: tautech on May 23, 2025, 09:34:51 pmI mentioned earlier that Josh had also posted a screenshot of his FFT settings.

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 23, 2025, 09:40:22 pm
content: from what I saw on Martins pictures from both Magnova and 3000 series I gotta say both are tempting still I need to settle for one :/

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2025, 10:06:32 pm
content: I'll put up some examples of 50 MHz FFT with a few scopes in the next day or so, SDG6000X and SSG3000X will be the sources....gotta big mess in the engineering shop to clean up first from yesterday's Ag equipment modifications......And it's perfect weather to check zero of my new to me shooter......Never enough time....

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 11:46:52 pm
content: Martin's time base and span were different than mine. In this one I matched his settings (+4 avg), and it might look similar to you now. 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 23, 2025, 11:57:22 pm
content: And since sampling was brought up, here's a comparison with the same cable and setup, but connected to the SDS5054X. It has a higher sampling rate than both of the HD scopes, but a slightly higher noise floor also.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 24, 2025, 05:00:59 am
content: I just made another cable, this time I did a much better job on the shielding braid than I did on the other one. It improved stability even further.Thanks,Josh

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 24, 2025, 05:09:29 am
content: now this is a proper noise floor - congratsjust one question - is this taken with SDS2000x hd series or your 5000x scope?

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 24, 2025, 05:15:33 am
content: Quote from: kmoonwalker on May 24, 2025, 05:09:29 amThanks!This is with the 2000X HD. The easy giveaway is the GSa/s rate is maxed at 2 on the 2k and 5 on the 5k. That and the 5k is slightly noisier (see reply 90 above). 😉

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 24, 2025, 05:23:27 am
content: Quote from: KungFuJosh on May 24, 2025, 05:15:33 amI do not have Siglent specs so well in my head and on some scopes there are settings to tamper with so better to ask and be on safe sideMeans that noise floor is pretty good on 2000 and 3000 series and that is valueable info for me - Many thanks!

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 24, 2025, 05:58:21 am
content: Quote from: kmoonwalker on May 24, 2025, 05:23:27 amNoise floor is practically the same between those two. In theory, the 2000 might be slightly better because of the higher range of the 3000 series. I've not seen anything that convinced me one way or the other tho. Both are excellent.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2025, 10:04:29 am
content: Quote from: kmoonwalker on July 22, 1970, 07:44:02 amYou ain't seen my contribution yet !Started building a series of screenshots before a planned dinner with lifelong friends interrupted proceedings and now with 3 too many under the belt will need to wait until tomorrow to complete.....

author: egonotto
author_rank: Super Contributor
timestamp: May 25, 2025, 01:19:40 am
content: Hello,surprisingly, the noise of the SDS3034X HD in the 1 V/div range is slightly better than that of the SDS2104X HD.With the SDS3034X HD with a bandwidth of approximately 420 MHz, the noise is at 4 mVrms.With the SDS2104X HD with a bandwidth of approximately 180 MHz, the noise is slightly above 5 mVrms.Best regardsegonotto

author: tautech
author_rank: Super Contributor
timestamp: May 25, 2025, 08:00:28 am
content: Quote from: tautech on May 23, 2025, 10:06:32 pm50 MHz 0dBm FFT tests with 50 MHz span using SSG3021X only...too much dicking around with cabling otherwise.Siglent 6 GHz rated 600mm N type cable with N-BNC adapter used for all tests, except SDS800X HD when a Tek 50 Ohm feedthrough was also used to mimic the 50 Ohm input 800X HD models do not have.All screenshots used a Max Hold setting and max FFT pts (2-8 MPts) available in each model provided and last we played with some ERES and a narrower Span with SDS6204A.Take note of the Span used, RBW settings, reported frequencies and amplitudes in each screenshot.Attachment filenames represent the model in use.We start with a FFT from SVA1032X and work to SDS6204A.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 25, 2025, 02:19:53 pm
content: Our time bases were at 2us/div. Here's 1ms:Same setup, switched to 2us:There's no comparison if we don't keep our setups consistent.

author: kmoonwalker
author_rank: Frequent Contributor
timestamp: May 25, 2025, 03:39:56 pm
content: many thanks to everyone for all effort

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 27, 2025, 02:56:45 am
content: I thought this was an interesting comparison. SML03 sweeping with the same short hyperflex 5 cable. SDS5054X vs SDS2504X HD.Green is the 2000X HD for anybody that doesn't know the model differences.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 29, 2025, 08:16:28 pm
content: Man, I really need to get my hands on that calibration software.Does anybody have any idea where to find the R&S calibration software for the SML series?Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 03, 2025, 03:01:39 am
content: OTOH, some dumbass tried to do a bandwidth sweep with a 20M filter on the scope, and didn't realize it right away.* Then he went and connected a V3500A to the SML03, and stepped in 10MHz intervals from 10MHz to 1GHz, and the SML was actually in spec including linearity.From 10MHz to around 700MHz, the SML was within ~0.2dB of the value, and only when it got close to 1GHz did it almost reach the ~0.5dB datasheet spec.*thought there might be something wrong with the new attenuator. 🙄🤣