EEVblog® Electronics Community Forum
Products => Test Equipment => Topic started by: KungFuJosh on May 04, 2025, 10:57:35 pm
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This weekend I got an R&S SML03 to play with. So far, I like it:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560470;image)
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-PAPST
12V DC, 160mA (SML service manual specifies 12V, 170mA max)
Passwords (use at your own risk):
LEVEL 1 Password: 123456
LEVEL 2 Password: 261339
LEVEL 3 Password: 710845
LEVEL 4 Password: 593748
From the manual:
Password 1 deactivates the lock for the calibration of Main Loop, Level Preset, LFGen Level, Leve,
IF Filter, Harm Filter, Mult Filterl.
Password 2 deactivates the lock for the calibration of RefOsc.
Password 3 factory internal
Password 4 factory internal
ETA: 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 model LPQ154 datasheet added.
ETA3: Maintenance manual section including error codes added.
Thanks,
Josh
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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
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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-PAPST
12V DC, 160mA (SML service manual specifies 12V, 170mA max)
Operating voltage: 8-15V DC
Fan dimensions: 60x60x25mm
Fan efficiency: 40m³/h (~23.5CFM)
Noise level: 35dBA
Rotational rate/speed: 6100rpm
https://www.ebmpapst.com/us/en/products/compact-fans/axial-compact-fans/p/622N.html (https://www.ebmpapst.com/us/en/products/compact-fans/axial-compact-fans/p/622N.html)
What 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 FLX
12V DC, 80mA
Operating voltage: 12V DC
Fan dimensions: 60x60x25mm
Speed: 3000 RPM
Airflow: 29.2 m³/h (~17.7CFM)
Noise level: 19.3 dBA
The CFM difference is less than 6. Is 6CFM enough to worry about? The significant noise drop would be nice.
Thanks,
Josh
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I think it's cool that the SML can do
two three modulations at once.
Here's a 500MHz sine:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560502;image)
Here it is with FM modulation:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560506;image)
Here it is with AM modulation:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560510;image)
Here it is with both:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560498;image)
Thanks,
Josh
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Amplitude
modulation sweep 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.
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Amplitude modulation sweep 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.
I'd love an SSG3021X. Send me one! 😉
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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:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560560;image)
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560556;image)
Now the waveform counters are all spot on:
Adjusted reference output from SML03:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560564;image)
10MHz RF Output:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560568;image)
500MHz RF Output:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2560572;image)
Thanks,
Josh
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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.
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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
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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/#msg5904862 (https://www.eevblog.com/forum/testgear/siglent-sds2000x-hd-12bit-(published-for-chinese-domestic-market-only)/msg5904862/#msg5904862)
10kHz: 208.6mV = -0.603414 dBm
100kHz: 179.4mV = -1.913251 dBm
500kHz: 131.8mV = -4.591392 dBm
1MHz: 122.1mV = -5.255387 dBm
10MHz: 143.36mV = -3.86114 dBm
100MHz: 122.9mV = -5.198662 dBm
500MHz: 98.5mV = -7.120975 dBm
Phew... :phew:
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?
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10kHz: 208.6mV = -0.603414 dBm
100kHz: 179.4mV = -1.913251 dBm
500kHz: 131.8mV = -4.591392 dBm
1MHz: 122.1mV = -5.255387 dBm
10MHz: 143.36mV = -3.86114 dBm
100MHz: 122.9mV = -5.198662 dBm
500MHz: 98.5mV = -7.120975 dBm
Phew... :phew:
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?
I'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
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Hi,
My DAQ6510 seems to be the best option
Its 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. :-//
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Hi,
My DAQ6510 seems to be the best option
Its 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. :-//
That'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
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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.
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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. 🤣
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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
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It took 24 minutes to update the firmware, which was hilarious because the SML says FASTLOAD on the screen the whole time.
:-DD
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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.
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(https://media.tenor.com/rcZMAz3r-fQAAAAM/borat-very.gif)
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 213mV
300MHz 201mV
400MHz 191mV
500MHz 176mV
600MHz 136mV
I 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
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Hi,
Congrats... ;)
Now do a sweep....
By the way:
500MHz 176mV
600MHz 136mV
That 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.
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Have you tried other coax cables ... I find they vary some at the higher frequencies.
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Hi,
Congrats... ;)
Now do a sweep....
Thanks! It's running now. 😉
That 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.
That's what I assumed...and why I put an offer on an RF power meter. 😉😉
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Have you tried other coax cables ... I find they vary some at the higher frequencies.
Right 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.
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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?
Does 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.
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Stability of the internal ref seems okay.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2562406;image)
ETA: Updated photo.
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I think this is the first time I've ever used the TinySA for something besides it's signal generator. 🤔
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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,
Josh
ETA: 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.
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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. 🤷
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The stock fan has a higher pitch noise, that is more annoying than the Noctua fan ....
If you wait long enough, higher pitch noises won't annoy you nearly as much as they do now :-DD
Thanks for all the great write-ups!
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The stock fan has a higher pitch noise, that is more annoying than the Noctua fan ....
If you wait long enough, higher pitch noises won't annoy you nearly as much as they do now :-DD
Thanks for all the great write-ups!
I 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). 😉
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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
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Here are some photos of the allegedly defective output unit. Nothing jumped out at me for obvious issues.
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Is the red circle the output?
Then it should be some kind of relay.
The yellow mark looks like a suspicious solder joint.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2565088;image)
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Is the red circle the output?
Then it should be some kind of relay.
The yellow mark looks like a suspicious solder joint.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2565088;image)
Good 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
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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.
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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.
It 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.
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That's still brand new; my SML01 had over 100,000 hours on it. ;)
(No joke)
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That's still brand new; my SML01 had over 100,000 hours on it. ;)
(No joke)
Good 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.
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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....
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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.
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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
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Here's what the SML-B3 option unit looks like.
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Just for fun, here are some photos of the PSU.
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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
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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.
You were right anyway. I posted my results above- the Noctua lost. My second SML03's stock fan is much quieter, and not an issue.
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.
That'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.
Better repair the 3Ghz module, I think what you have marked is the RF coupler for the ALC.
I 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)?
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...
4227T 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
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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.
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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.
The 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.
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.
Measured on:
SDS2504X HD oscilloscope
TinySA Ultra
Keysight V3500A RF Power Meter
All devices are agreeable (TinySA required minor level adjustment at 1st frequency, then matches levels across the range within reason given its limitations).
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.
There'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.
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 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.
I have edited your picture to explain the modules, the OPU1 is on the mainboard, the OPU2 is the doppler/trippler module.
Thanks. 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
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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:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2568828;image)
B3 hardware not installed:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2568820;image)
B3 hardware installed:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2568824;image)
Thanks,
Josh
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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:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2568888;image)
That must have been some special wire wiggling. 🤷
Thanks,
Josh
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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.
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Please look under utilities, there you will find the item Install for SME and SMIQ.
This 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.
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.
B3 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.
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.
Yes, 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
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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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569128;image)
Pulse Period, Width, and Delay all say Option Absent.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569132;image)
Selecting one of them shows "parameter not available."
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569124;image)
But then it shows the current frequency there for some reason. Maybe a 20 year old bug?
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569140;image)
Then when I turned on the Double Pulse State option, it gave the error (same as other mainboard).
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569136;image)
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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569144;image)
I set the values randomly and pretty high, so now when I turn on Double Pulse State I get an error.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569148;image)
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I RTFM and it didn't help. :-DD
Thankfully, Paul has an awesome video (as usual):
https://www.youtube.com/watch?v=EXx8mMqJN70 (https://www.youtube.com/watch?v=EXx8mMqJN70)
This one too: video (https://youtu.be/0GPp6ncHaJw?feature=shared) (embedding is disabled in that one).
Now I understand it a little better, and got rid of the error.
Thanks,
Josh
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Aaaaaaaaaaaand the Pulse generator works fine...now that I know how to use it. 🤣
Thanks for the awesome videos, Paul!
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569202;image)
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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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2569506;image)
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
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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. 🤷
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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.
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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.
Regardless, 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
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Yesterday I was playing with the pulse generator "video out" which directly outputs the set pulse. Today, I played with the pulse modulation.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2570304;image)
It gets weirder when you combine Pulse + AM + FM modulation.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2570308;image)
Messing with these settings also helped improve my triggering skills, which was a nice bonus. 😉
Thanks,
Josh
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Yesterday I was playing with the pulse generator "video out" which directly outputs the set pulse. Today, I played with the pulse modulation.
Messing with these settings also helped improve my triggering skills, which was a nice bonus. 😉
1st grade simple stuff ! :P
When you need a Zone trigger or 2 things are really getting interesting..... :scared:
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Messing with these settings also helped improve my triggering skills, which was a nice bonus. 😉
1st grade simple stuff ! :P
When you need a Zone trigger or 2 things are really getting interesting..... :scared:
If you knew what I was actually referring to, you'd call it kindergarten. 😉
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Is it correct that those RF switches marked 4227T are actually SSW-124?
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More modulation fun.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2570776;image)
SML03 settings:
100kHz -10dBm
AM Modulation: 80%
Phase Modulation: 1.800 rad
LFGen Freq: 100Hz
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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
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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
I 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
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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.
(https://www.jmpguitars.com/images/scope1.gif)
(https://www.jmpguitars.com/images/scope2.gif)
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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
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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
Agreed. Does the scope have an FFT?
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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... 🤔
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How's this look? Did I set it up correctly?
SML03:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572470;image)
SDG2122 for comparison:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572466;image)
Thanks,
Josh
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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 ^^
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hmm you written some time ago about it being able to modulate the waveform etc - did you disabled all
😉
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 ^^
I 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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572608;image)
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
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now this is more like Rohde I remember - glad you have it pinpointed :)
I 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
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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 it ;)
You 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 ;)
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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
- 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).
M&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.
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)
All 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.
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 it ;)
Let's stay just shy of that rabbit hole. 😉
Thanks,
Josh
PS. 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).
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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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572752;image)
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:-+
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 :)
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How's this look? Did I set it up correctly?
SML03:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572470;image)
SDG2122 for comparison:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572466;image)
Thanks,
Josh
I recreated this earlier.
Source SDG6052X, Scope SDS3104X HD, Magnova BMO350.
Coefficients for siglent Hamming and Hann, for Magnova Hamming.
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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
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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
Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
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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
Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
as 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 setup
or 3000 series really has such better dynamic range for fft
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Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
Except for the averaging, I followed Josh's settings, which he shared in the post I quoted(picture).
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Hello,
Martin uses 65536 samples while Josh only uses 16384 samples.
Best regards
egonotto
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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
Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
as 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 setup
or 3000 series really has such better dynamic range for fft
A Peak Hold setting might account for that.
Without a Menu showing how might anyone know ? :-//
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@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 (https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5923934/#msg5923934)
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yep but samples amount should not impact the noise floor level - just better representation
I 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, too
I 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 :)
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A Peak Hold setting might account for that.
Without a Menu showing how might anyone know ? :-//
I mentioned earlier that Josh had also posted a screenshot of his FFT settings.
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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 :/
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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....
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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. 😉
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572920;image)
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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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2572930;image)
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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.
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2573116;image)
Thanks,
Josh
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:-+
now this is a proper noise floor - congrats
just one question - is this taken with SDS2000x hd series or your 5000x scope?
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:-+
now this is a proper noise floor - congrats
just one question - is this taken with SDS2000x hd series or your 5000x scope?
Thanks!
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). 😉
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:-+
now this is a proper noise floor - congrats
just one question - is this taken with SDS2000x hd series or your 5000x scope?
Thanks!
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. 😉
I 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 side :)
Means that noise floor is pretty good on 2000 and 3000 series and that is valueable info for me - Many thanks!
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Means that noise floor is pretty good on 2000 and 3000 series and that is valueable info for me - Many thanks!
Noise 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.
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Means that noise floor is pretty good on 2000 and 3000 series and that is valuable info for me - Many thanks!
You ain't seen my contribution yet ! :P
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..... :=\
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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 regards
egonotto
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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 source.
50 MHz 0dBm FFT tests with 50 MHz span using SSG3021X only...too much dicking around with cabling otherwise. :horse:
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.
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Our time bases were at 2us/div. Here's 1ms:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2574438;image)
Same setup, switched to 2us:
(https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/?action=dlattach;attach=2574444;image)
There's no comparison if we don't keep our setups consistent.
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many thanks to everyone for all effort :)
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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
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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
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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. 🙄🤣
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Hello. Does anyone know if the R&S SML B5 hardware option will also work if you transfer it from one SML unit to another that wasn't originally equipped with it?
Regards, Jörg
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Hello. Does anyone know if the R&S SML B5 hardware option will also work if you transfer it from one SML unit to another that wasn't originally equipped with it?
Regards, Jörg
My experience with this series was that things can be plugged in as swappable hardware modules without worrying about it needing activation. You will need to run self cal though.
For example, I had no issue with or without B5. I could also swap the 2G/3G board, or run without it. I swapped mainboards between units, etc.
Thanks,
Josh
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Has anyone been able to find a replacement display for this generator?
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Has anyone been able to find a replacement display for this generator?
Yeah...that's why I have a parts unit available with a dead display. ;)
But no, outside of buying parts units, there hasn't been a great option for it. You can buy a parts unit with a (at least mostly) working display IME for less than the replacement screen.
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I like you could not get the pulse generator to work. I will watch the video and try again.
Do you mind listing what options are showing on your unit? I have the SML01.
Can you just change the coin cell battery or do you have to apply voltage and then change the coin cell battery to save the memory contents? I will also upgrade to the latest firmware.
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And asking Rohde for any service help is a waste of time. They told me they "dispose of all documentation and firmware and everything else" when they discontinue a unit. Their main market seems to be government and their attitude to smaller businesses is not that great.
I have a few pieces of their equipment and every time I ask for a firmware updates I get the same answer. The make the most expensive disposable equipment in the world with the shortest possible support life. And for this reason when I was in a position of buying equipment for my company I would not buy their new equipment. To me it was simple when a company does not want to release user, service, firmware or service bulletins they not really interested in customer support or building a loyal customer especially if the equipment is still working and calibrated. Agilent/Keysight were good in this regard so I purchased their equipment since they were very accessible and their support and calibration centre was very easy to get in contact with and to deal with. They even calibrated their older discontinued models.
Has anyone been able to find a replacement display for this generator?
Yeah...that's why I have a parts unit available with a dead display. ;)
But no, outside of buying parts units, there hasn't been a great option for it. You can buy a parts unit with a (at least mostly) working display IME for less than the replacement screen.
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I like you could not get the pulse generator to work. I will watch the video and try again.
Do you mind listing what options are showing on your unit? I have the SML01.
Can you just change the coin cell battery or do you have to apply voltage and then change the coin cell battery to save the memory contents? I will also upgrade to the latest firmware.
My pulse generator works great. I didn't know how to use it initially. ;)
IME with the SML series, any hardware option you install correctly will become available without much effort.
I didn't bother applying voltage. The only thing you'll lose is the user calibration, which you'll want to run again anyway.
Regarding support, Keysight is not better than R&S at all. The difference is that Keysight will happily overcharge you for calibration. Better to go to an independent cal lab instead either way.
Both companies prefer large businesses, and neither care about small biz or hobby users. I have products from both companies, and between the two, I've found R&S easier to deal with. That being said, both of them are ridiculous. :-DD
For the R&S stuff that had publicly available firmware, it's mostly available on their site if you have a company login.
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And asking Rohde for any service help is a waste of time. They told me they "dispose of all documentation and firmware and everything else" when they discontinue a unit.
Who told you that??? If you have an email from us or the name of the person you spoke to, please PM them to me.
We (R&S) normally provide full support for products for at least 5 years after we officially discontinue it, and often provide best effort service and calibration after that. I have personally seen repairs and calibration performed many, many more years that than after instruments were discontinued.
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Hi
Does anybody have experience if SML02 boots and runs without the display module and cable, not just the LDC but the whole unit? I have a parts donor SML02 which has lost its display unit and I wonder if I still could use the generator via the GPIB or RS232 interface with a PC and some simple app.
Br, jackob
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Hi,
Currently i dont know what to say but, as far as i can see SML03 devices can output 10 to 500kHz from its LF output using its internal LFGenerator.
Is that correct? If so, what a nice device to have.
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Hi,
Currently i dont know what to say but, as far as i can see SML03 devices can output 10 to 500kHz from its LF output using its internal LFGenerator.
Is that correct? If so, what a nice device to have.
The LF gen can go up to 1MHz, but in general, it's not great. It does well for its intended use for modulation on the main RF output, but the LF output isn't pretty. I dunno if it can modified or optimized to be better, but I've had a few of these, and I've never seen an LF output on them that didn't make me think I should use something else for that instead. ;) ...though I guess that depends really on what you need it for.
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I finally found some rack ears for my SML03. I got a used set from ArtisanTG for $80+$26 to ship. Bastards are expensive, but it was still better than buying them new for $188 which is mildly insane for a pair of 2U rack ears.
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I am going to jump on this thread with some issues. Who knows, might even be able to fix them.
I got my dirt-cheap SML03 with B19 rear IO and B3 pulse mod a couple days ago and... Issues. The output power is almost consistently 25dB down from the 0dBm I tested it at across its entire range.
I do a sweep on my SA here to show (Picture is dark to enhance screen details). First step will be tracking the signal through the RF paths. I am suspecting one of the GaAs switches has gone bad in the 1GHz module + RF attenuator as they usually do, but will have to test them to be sure nonetheless.
- Tyler
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I am going to jump on this thread with some issues. Who knows, might even be able to fix them.
I got my dirt-cheap SML03 with B19 rear IO and B3 pulse mod a couple days ago and... Issues. The output power is almost consistently 25dB down from the 0dBm I tested it at across its entire range.
I do a sweep on my SA here to show (Picture is dark to enhance screen details). First step will be tracking the signal through the RF paths. I am suspecting one of the GaAs switches has gone bad in the 1GHz module + RF attenuator as they usually do, but will have to test them to be sure nonetheless.
I don't think that's likely since it's consistent across the board. I suspect 1 of 2 things:
1. Either your SA is measuring incorrectly, or
2. The B3 module might be dropping the output level
If you have a different power meter, then you can rule out #1.
To rule out #2, you can bypass the B3 module and test again.
You can also run through a full self calibration after a good warmup, and if you're lucky that might have an impact on the output level.
ETA: Just looked closer at your SA. It says input attenuator 30dB. Does that mean the input is dropped 30dB, and your output is actually close to 0 dBm? I dunno if it compensates to adjust the displayed level or not.
Thanks,
Josh
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I am going to jump on this thread with some issues. Who knows, might even be able to fix them.
I got my dirt-cheap SML03 with B19 rear IO and B3 pulse mod a couple days ago and... Issues. The output power is almost consistently 25dB down from the 0dBm I tested it at across its entire range.
I do a sweep on my SA here to show (Picture is dark to enhance screen details). First step will be tracking the signal through the RF paths. I am suspecting one of the GaAs switches has gone bad in the 1GHz module + RF attenuator as they usually do, but will have to test them to be sure nonetheless.
I don't think that's likely since it's consistent across the board. I suspect 1 of 2 things:
1. Either your SA is measuring incorrectly, or
2. The B3 module might be dropping the output level
If you have a different power meter, then you can rule out #1.
To rule out #2, you can bypass the B3 module and test again.
You can also run through a full self calibration after a good warmup, and if you're lucky that might have an impact on the output level.
ETA: Just looked closer at your SA. It says input attenuator 30dB. Does that mean the input is dropped 30dB, and your output is actually close to 0 dBm? I dunno if it compensates to adjust the displayed level or not.
Thanks,
Josh
Number 1 can be ruled out. My U2000H reports the exact same power level as the SA.
As for the attenuation 30dB on the SA, the system compensates already for that, which was indicated by my 8594E, and the U2000H measurements.
I will have to try and bypass B3, see if it makes a difference. Given I see no ALC error, and I assume this is in the 2/3G board, it could potentially be.
I will have a quick look, see if that fixes it.
- Tyler
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Well, looks like that fixed it. B3 is the problem, now time to investigate why.
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Well, looks like that fixed it. B3 is the problem, now time to investigate why.
That's what I figured. It also has an attenuation level thingamabob inside. B3 also lowered my output, but only a couple dB.
Do the full self calibration though before you do anything else (with B3 installed). I think I posted how to do it earlier in the thread.
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Oh, I was wrong. It has three of those bastard switches in it.
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Well, looks like that fixed it. B3 is the problem, now time to investigate why.
That's what I figured. It also has an attenuation level thingamabob inside. B3 also lowered my output, but only a couple dB.
Do the full self calibration though before you do anything else (with B3 installed). I think I posted how to do it earlier in the thread.
No joy with the selfcal, seems about the same now. Also noticed that this issue is dumping a bunch of harmonics into the signal output... First harmonic of 100MHz for example, is only about 15dB down. This wasn't present when I had the module bypassed. Something fishy going on here.
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As a follow up, I can see something is wrong here. Referring to the service manual under sec. 6 for the Pulse modulator, they have all the test points written out with the expected values. Everything was fine when testing with the built-in utility (Even the GaAs pin voltages...), but the post-N8 rf level (TP902) seems to be troublesome.
Should be: 150 - 250mV
Was Tested: 4.196mV
- Tyler
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I wonder where that tp actually is. Anyway, review this thread a little. It seems I corrected my output level issue at B3 by cleaning and wiggling things. :-DD
https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5917594/#msg5917594 (https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5917594/#msg5917594)
And here's the firmware update info if you need it: https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5918402/#msg5918402 (https://www.eevblog.com/forum/testgear/rohde-schwarz-sml-series-signal-generators-sml01-sml02-sml03-smv03/msg5918402/#msg5918402)
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This reset the cal after updating, did it not?
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I don't think fw update affected factory cal, but I've done the self cal a bunch of times after that anyway. No issues with mine other than 0dB might be slightly lower than 0 last I checked, but I don't need it to be perfect.
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I don't think fw update affected factory cal, but I've done the self cal a bunch of times after that anyway. No issues with mine other than 0dB might be slightly lower than 0 last I checked, but I don't need it to be perfect.
I just read through the service docs again, and looks like N8 is the output amplifier stage at the end of the module. It is probably not an overly complex part (hopefully), but if not misbehaving, would explain the extra harmonics I see with it introduced into the RF path.
I did try the "tap the parts and see if it fixes itself" method to no avail.
- Tyler
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Did you clean anything with IPA? I'd clean anything suspect and all the signal path connectors.
You might need to replace the SSW-124 (marked 4227T) in there. Those are not easy to find parts though. It's easier to find an R&S donor unit to scavenge parts from. You could also try reflowing and cleaning the one you suspect. It might be a good idea to clean the whole module anyway.
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Did you clean anything with IPA? I'd clean anything suspect and all the signal path connectors.
You might need to replace the SSW-124 (marked 4227T) in there. Those are not easy to find parts though. It's easier to find an R&S donor unit to scavenge parts from. You could also try reflowing and cleaning the one you suspect. It might be a good idea to clean the whole module anyway.
On that thought, I actually used my near field probes to trace the input signal through the 4227Ts. I have actually seen no significant signal attenuation until the signal trace arrives at the B3 amp section (closest box to output connector, and the hottest part on a thermal camera).
Apart from that, all the connectors were cleaned, and re-torqued to 0.90N•m. The board was scrubbed, and I reflowed almost all the joints on the board top and bottom side.
A donor unit is likely going to cost multiple fold compared to what I spent already, so I will keep looking at either component-level repair or just bypassing the module.
- Tyler
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Can you share some thermal images of it?
What do the 4227Ts voltages look like inside of B3?
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Tested all 3 switches:
SW1:
- CTRL1: 1.522V
- CTRL2: -6.066V
SW2:
- CTRL1: 1.512V
- CTRL2: -6.052V
SW3:
- CTRL1: 0.7891V
- CTRL2: -6.003V
I am guessing SW3 might have some sort of problem. But, when I select the pulse gen modulation options in the menus, CTRL1 goes to 1.5 or so volts... UTSource has some of these switches, but they're USD$ 102.76 each plus USD$ 30.00 ship... No thanks!
Attached a thermal shot of the module.
- Tyler
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If you're comfortable soldering/desoldering those, you can swap SW2 and SW3 and see if the voltage difference follows the chip or not...or if it magically fixes the problem. ;)
It's been a while since I checked UTSource for those, but they were $6 at the time. :palm:
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If you're comfortable soldering/desoldering those, you can swap SW2 and SW3 and see if the voltage difference follows the chip or not...or if it magically fixes the problem. ;)
It's been a while since I checked UTSource for those, but they were $6 at the time. :palm:
Interestingly, my module seems to differ from your B3 in two small ways...
The inductor near the output connector is seemingly bodged on in mine, with a wire connecting one side of it to the cap near it.
Other one, is that I have two white switches, and one SOP-8 looking one.
Not sure if it's just a component shortage that would have mixed these, but the inductor thing was interesting. I will get a picture of it when I have it open again.
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I definitely want to see some photos. I wonder if somebody previously attempted repair.
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Here ya go... Photos are quite hi-res, but it doesn't seem to show well on the forum.
You can also see the main output module was RMA'd in '04
- Tyler
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You can right-click and open the image in a new tab to view it full size.
Anyway, since your worst case scenario is to bypass B3 and not have any issues anymore...
How do you feel about swapping SW2 and SW3? I'm curious about that voltage.
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Tried removing SW3, it's bolted down pretty good with these tabs on the side, my hot air has a difficult time getting it pulled up.
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It might be easier with some flux and an iron, but you'll need to do a good job cleaning again.
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I requested a quote for these: https://www.utsource.net/itm/p/12607896.html (https://www.utsource.net/itm/p/12607896.html)
They quoted $10 each for a quantity of 10 (used :palm:). I don't know if quantity effects it or not. If you requested what they show as 4227T, then it's probably the wrong part anyway.
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These are the ones I was looking at: https://www.utsource.net/itm/p/9271510.html?srsltid=AfmBOopPQx8MNEpC7gQIxkpv9SFEWlaXGT0B78kVxJB8Olxne8BJL4qE (https://www.utsource.net/itm/p/9271510.html?srsltid=AfmBOopPQx8MNEpC7gQIxkpv9SFEWlaXGT0B78kVxJB8Olxne8BJL4qE)
Probably were the wrong part then.
- Tyler
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MASWSS0157 from MACOM and AW002R2-12 from Skyworks both come in SO8 packages and seem to have the same pinout as the P35-4227-3T. The control voltage is similar since they are also GaAS devices (i.e., depletion mode MESFETs), and both are rated to 2.5 GHz. Unfortunalety they are also obsolete.
Then there is the HMC234C8 in a SO-8 package but with different pinout. Obsolete as well. Maybe you can find a suitable GaAS SPDT switch in a SOT23-6 package and bodge that in if all else fails. This will likely distort amplitude flatness, but you should be able to calibrate that out if you can get your hands on the required cal software.
These old GaAs devices are prone to failure as the processes apparently weren't yet well under control back then.
Edit: I just realize that the P35-4227-3T is a terminated switch, i.e., the switch terminal that is not in the active path is terminated into 50 ohms. You should look out for that when searching for a replacement.
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Be careful with part identification. It's a switch (DC - 6GHz High Isolation SPDT GaAs MMIC Switch); not an oscillator or a JFET or a 2 pin socket. All of which can easily be confused by the part numbers.
This is the correct replacement (the only source I know of, unfortunately questionable being sold as used): https://www.utsource.net/itm/p/12607896.html (https://www.utsource.net/itm/p/12607896.html)
Datasheet attached.
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Be careful with part identification. It's a switch (DC - 6GHz High Isolation SPDT GaAs MMIC Switch); not an oscillator or a JFET or a 2 pin socket. All of which can easily be confused by the part numbers.
This is the correct replacement (the only source I know of, unfortunately questionable being sold as used): https://www.utsource.net/itm/p/12607896.html (https://www.utsource.net/itm/p/12607896.html)
Datasheet attached.
Might need many of your replacements there, in the event that they are already broken. Can't say I am fond of the idea of "used" chips, but might not have any options anyways.
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If you can manage to swap SW2 and SW3, then you'll get a better idea after testing the voltages. If the voltage difference follows the chip from SW3, then you know it's the chip.
If you can't swap the chips you have, then ordering more of them won't help until you can swap them anyway.
Something like this might help:
https://www.youtube.com/watch?v=7kyaz4Zrd78 (https://www.youtube.com/watch?v=7kyaz4Zrd78)
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Datasheet attached.
If that's the correct datasheet, the HMC347ALP3E from Analog Devices/Hittite and the MSWA2-50+ from Minicircuits are both available and perfect matches (nonreflective SPDT GaAs switch with negative control voltage and comparable isolation and loss) -- except for the package. Since both are 3x3mm QFNs you could make a small adapter board with castellated holes on the sides that fits on the SO8 footprint.
That's the pulse modulator assembly, right? I think the attenuator in the SML has similar switches and a software temperature compensation, therefore it is important to stick with GaAs MESFET devices, although I don't think there is temperature compensation in the pulse modulator.
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Datasheet attached.
If that's the correct datasheet, the HMC347ALP3E from Analog Devices/Hittite and the MSWA2-50+ from Minicircuits are both available and perfect matches (nonreflective SPDT GaAs switch with negative control voltage and comparable isolation and loss) -- except for the package. Since both are 3x3mm QFNs you could make a small adapter board with castellated holes on the sides that fits on the SO8 footprint.
That's the pulse modulator assembly, right? I think the attenuator in the SML has similar switches and a software temperature compensation, therefore it is important to stick with GaAs MESFET devices, although I don't think there is temperature compensation in the pulse modulator.
This could also work, but will probably be magnitudes more expensive on a gamble with the used parts. Once I get a preheater for my soldering bench, I might have a bit more luck removing this switch and then replacing all of them.
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Datasheet attached.
If that's the correct datasheet, the HMC347ALP3E from Analog Devices/Hittite and the MSWA2-50+ from Minicircuits are both available and perfect matches (nonreflective SPDT GaAs switch with negative control voltage and comparable isolation and loss) -- except for the package. Since both are 3x3mm QFNs you could make a small adapter board with castellated holes on the sides that fits on the SO8 footprint.
That's the pulse modulator assembly, right? I think the attenuator in the SML has similar switches and a software temperature compensation, therefore it is important to stick with GaAs MESFET devices, although I don't think there is temperature compensation in the pulse modulator.
The MSWA2-50+ certainly looks interesting at $19 a pop. The other one for $104 is less appealing.
I was already considering an adapter board, but my SML is working fine so there was no urgency for me. ;)
There was another chip people were bodging in to replace these, but I don't remember what it was. It might also be worth considering an adapter for if the part number is found again and still available at a reasonable price.
Yes, the output module/attenuator has a bunch of these same switches.
Thanks,
Josh
ETA:
I'm still reviewing the datasheets, but it looks like HMC347ALP3E is not as a good of a choice compared to the MSWA2-50+.
Comparisons up to 3GHz:
SSW-124 (original):
Max insertion loss: 1.0dB
Typical isolation: 40dB
Minimum isolation: 30dB
Operating temp: -45C to +85C
Switching speed: 3nsec
Max control voltage: -10V
VSWR: 1.25
Current Price: OBSOLETE
MSWA2-50+:
Max insertion loss: 1.0dB
Typical isolation: 47dB
Minimum isolation: 29dB
Operating temp: -40C to +85C
Switching speed: 7nsec
Max control voltage: -8.5V
VSWR: 1.33
Current Price: $19
KSW-2-46+ (has been used previously for this purpose):
Max insertion loss: 1.8dB
Typical isolation: 40dB
Minimum isolation: 28dB
Operating temp: -55C to +100C
Switching speed: 4nsec
Max control voltage: -8V
VSWR: 1.3
Current Price: OBSOLETE
HMC347ALP3E:
Max insertion loss: 1.9dB
Typical isolation: 54dB
Minimum isolation: 50dB
Operating temp: -55C to +85C
Switching speed: 10nsec
Max control voltage: -7.5V
VSWR: 1.33
Current Price: $104
R&S has been known to push the voltages on these switches (which likely contributes to their failure rate), so HMC347ALP3E is not a good choice beyond the price.
Anyway, somebody smarter than me should compare further to make sure we didn't miss anything. ;)
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R&S has been known to push the voltages on these switches (which likely contributes to their failure rate), so HMC347ALP3E is not a good choice beyond the price.
Anyway, somebody smarter than me should compare further to make sure we didn't miss anything. ;)
No idea. The HMC347ALP3E is spec'd to higher frequencies, so you can speculate that its FETs have shorter gates and hence a smaller Schottky breakdown voltage. Depending on which philosophy the company follows with their abs. maximum ratings and which margins they apply, this may be the reason for the -7.5V max control voltage. On the other hand, these devices might be manufactured in a more modern process than the original ones, which makes them much less prone to deterioration processes like gate sinking (i.e., the gate diffusing into the semiconductor material), which is dependent on gate-source voltage and temperature.
But that is all just reading tea leaves. For me, the deciding factor would be the price. ;)
That said, the old GaAs devices are notorious for failure, even if they are new old stock. I've had a SML where the signal level fluctuated wildly as soon as it warmed up. Presumably the switches in the attenuator. Since I bought it from a dealer, I simply sent it back (and received a better one as compensation). But I’ve replaced a few of the damn things in various devices. Most recently in an R&S EB200 wideband receiver.
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R&S has been known to push the voltages on these switches (which likely contributes to their failure rate), so HMC347ALP3E is not a good choice beyond the price.
Anyway, somebody smarter than me should compare further to make sure we didn't miss anything. ;)
No idea. The HMC347ALP3E is spec'd to higher frequencies, so you can speculate that its FETs have shorter gates and hence a smaller Schottky breakdown voltage. Depending on which philosophy the company follows with their abs. maximum ratings and which margins they apply, this may be the reason for the -7.5V max control voltage. On the other hand, these devices might be manufactured in a more modern process than the original ones, which makes them much less prone to deterioration processes like gate sinking (i.e., the gate diffusing into the semiconductor material), which is dependent on gate-source voltage and temperature.
But that is all just reading tea leaves. For me, the deciding factor would be the price. ;)
That said, the old GaAs devices are notorious for failure, even if they are new old stock. I've had a SML where the signal level fluctuated wildly as soon as it warmed up. Presumably the switches in the attenuator. Since I bought it from a dealer, I simply sent it back (and received a better one as compensation). But I’ve replaced a few of the damn things in various devices. Most recently in an R&S EB200 wideband receiver.
There are a few other options that would have probably been better avenues. For the price I simply couldn't give this guy up though. Siglent's SSG5040X would probably have been a much better decision.
eBay seller refuses to help me at all it seems, so I am kind of out in the weeds on this one hence why I started my own debug. He's been MIA for the past while. I guess I should have expected this though.
- Tyler
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I designed the conversion PCB for the MSWA2-50+ to SSW-224. PCBWAY can probably make them, JLCPCB can't (too small for castellated holes - they require minimum 10mmx10mm).
Somebody else please verify.
If you order these, I recommend ENIG plating, and make sure to use at least 25u for hole copper thickness (https://www.pcbway.com/helpcenter/ordering_parameter_instruction/What_is_PCB_Hole_Copper_Thickness_.html).
And of course:
USE AT YOUR OWN RISK.
Thanks,
Josh
ETA: lol, it just occurred to me how tiny this is. Should be interesting to work with. :-DD
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eBay seller refuses to help me at all it seems, so I am kind of out in the weeds on this one hence why I started my own debug. He's been MIA for the past while. I guess I should have expected this though.
I know it's annoying, but given the price you paid for an SML03 that works fine except for the B3 option, I wouldn't worry about it. The PCB I made above should work to replace your bad switches.
Thanks,
Josh
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eBay seller refuses to help me at all it seems, so I am kind of out in the weeds on this one hence why I started my own debug. He's been MIA for the past while. I guess I should have expected this though.
I know it's annoying, but given the price you paid for an SML03 that works fine except for the B3 option, I wouldn't worry about it. The PCB I made above should work to replace your bad switches.
Thanks,
Josh
Nice boards, thanks! I was working on some adapters in Altium yesterday as well, it was just taking a while in between gaps of work. While I shouldn't really be concerned, and can bypass the problem, I still need to get some rigid coax and solder-cup SMA connectors to put the fix together.
I am still working on figuring out the switch removal. I am having the issue where the thermal pad on the board is sinking too much heat into my table when desoldering. The white switches are more problematic than the black ones as the difference is the ground pour under the chips.
- Tyler
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Nice boards, thanks! I was working on some adapters in Altium yesterday as well, it was just taking a while in between gaps of work. While I shouldn't really be concerned, and can bypass the problem, I still need to get some rigid coax and solder-cup SMA connectors to put the fix together.
I am still working on figuring out the switch removal. I am having the issue where the thermal pad on the board is sinking too much heat into my table when desoldering. The white switches are more problematic than the black ones as the difference is the ground pour under the chips.
You're welcome. Hopefully it helps somebody.
Removing those switches is probably easier on a hot plate, but you gotta be careful not to remove anything else. If I were to try it, I would use a hot plate with the chip quik kit I linked before. But, I'd probably fuck it up, so take that with a grain of salt. ;)
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Somebody else please verify.
I might be getting this wrong in my haste, but according to the schematic you posted you may need to swap the Control1 and Control2 lines (or RF_Out1 and RF_Out2). If I read the datasheets correctly, we have:
- Control1 = 0V, Control2 = -5V: RF_Out1 active on SSW-124, RF_Out2 active on MSWA2-50+
- Control1 = -5V, Control2 = 0V: RF_Out2 active on SSW-124, RF_Out1 active on MSWA2-50+
Since you wired RF_Out 1 on the SO8 to RF_Out1 on the QFN, and similarly for RF_Out2 as well as the Control lines, you need reversing them, don't you?
Again, I might mistaken, but please check. :)
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Somebody else please verify.
I might be getting this wrong in my haste, but according to the schematic you posted you may need to swap the Control1 and Control2 lines (or RF_Out1 and RF_Out2). If I read the datasheets correctly, we have:
- Control1 = 0V, Control2 = -5V: RF_Out1 active on SSW-124, RF_Out2 active on MSWA2-50+
- Control1 = -5V, Control2 = 0V: RF_Out2 active on SSW-124, RF_Out1 active on MSWA2-50+
Since you wired RF_Out 1 on the SO8 to RF_Out1 on the QFN, and similarly for RF_Out2 as well as the Control lines, you need reversing them, don't you?
Again, I might mistaken, but please check. :)
Good idea to check that. That's much more reading than I did. ;) Seems I need to study those a docs a little more.
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I'm not sure. This needs translation. ;)
It sounds like you're probably correct, but it's slightly ambiguous.
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I'm not sure. This needs translation. ;)
It sounds like you're probably correct, but it's slightly ambiguous.
Datasheet exegesis can be a source of true joy. This is one of the things you'd normally fix in software in your own designs. Anyway, as I read it, the two devices behave in opposite ways with respect to Control1 and Control2, so the lines should be reversed, but that doesn't necessarily mean anything. Maybe we can get another opinion. :)
Anyway, it's good to have a way to replace that switch. This won't be the last time one of those turds will fail in an SML, so thank you for designing it.
Perhaps you can panelize that small board somehow as a breakout board. That would make handling and soldering much easier. A FR4 thickness of 0.5mm would probably be ideal.
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I'm not sure. This needs translation. ;)
It sounds like you're probably correct, but it's slightly ambiguous.
Just having a quick look at your schematic versus the datasheets:
For MSWA2-50+:
1.) When VC1 = 0V, VC2 = -5/-8V => RFO1 = OFF, RFO2 = ON
2.) When VC1 = -5/-8V, VC2 = 0V => RFO1 = ON, RFO2 = OFF
For SSW-124:
1.) When VC1 = 0V, VC = -5V => J1-J2 path ON, J1-J3 OFF
2.) When VC2 = -5V, VC2 = 0V => J1-J2 path OFF, J1-J3 path ON
On your board:
RFI1 is connected to SOP8 pin 2. RFO1 is connected to SOP8 pin 5, RFO2 is on SOP8 pin 8.
- Looking at MSWA2-50+, the first case turns on RFO2, which means that SOP8 pin 2 is connected to SOP8 pin 8. In the second case, RFO1 is on, which connects SOP8 pin 2 to SOP8 pin 5.
- Looking at the SSW-128 Datasheet, the first case turns on J1-J2 path, connecting SOP8 pin 2 to pin 5. In the second scenario, J1-J3 path is connected, and thus SOP8 pin 2 is connected to SOP8 pin 8.
Assuming your PCB footprint for SOP8 is the same pin numbering as the SSW-124 part, I *think* the control lines probably need to be reversed.
Here's my interpretation:
╔════════╦════════╦════════════════╦════════════════╗
║ ║ ║ SSW-124 ║ MSWA2-50+ ║
╠════════╬════════╬════════════════╬════════════════╣
║ VC1 ║ VC2 ║ Connected Path ║ Connected Path ║
╠════════╬════════╬════════════════╬════════════════╣
║ OFF ║ -5/-8V ║ SOP8 (P2 - P5) ║ SOP8 (P2 - P8) ║
╠════════╬════════╬════════════════╬════════════════╣
║ -5/-8V ║ OFF ║ SOP8 (P2 - P8) ║ SOP8 (P2 - P5) ║
╚════════╩════════╩════════════════╩════════════════╝
- Tyler
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Ok, here it is with the control pins reversed. Board thickness reduced to 0.8mm.
I don't love that I needed to use vias with uneven tracks, but it's a switch, so I don't think it should matter so much. Anyway...
USE AT YOUR OWN RISK.
Thanks,
Josh
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Ok, here it is with the control pins reversed. Board thickness reduced to 0.8mm.
I don't love that I needed to use vias with uneven tracks, but it's a switch, so I don't think it should matter so much. Anyway...
USE AT YOUR OWN RISK.
Thanks,
Josh
Looks fantastic! I was wondering for mfg, if a flex PCB would be better thickness wise. It would probably be more susceptible to vibrations, but could be an option.
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I wouldn't go nuts with the PCB type. Flex PCB adds extra risks like copper tear out.
0.8mm FR4 should be fine. I would use ENIG and maybe a heavier weight, with a minimum of 25um for hole copper thickness.
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JLCPCB can't (too small for castellated holes - they require minimum 10mmx10mm).
At JLC, you don't necessarily need to enable the "Castellated Hole" option.
https://www.eevblog.com/forum/manufacture/manufacturing-less-than-half-castelated-holes-in-jlcpcb/msg6221843/#msg6221843 (https://www.eevblog.com/forum/manufacture/manufacturing-less-than-half-castelated-holes-in-jlcpcb/msg6221843/#msg6221843)
I've made a few PCBs in the past that violated the design rules for castellated holes, but there weren't any major issues, and JLC didn't say anything about it.
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At JLC, you don't necessarily need to enable the "Castellated Hole" option.
I've made a few PCBs in the past that violated the design rules for castellated holes, but there weren't any major issues, and JLC didn't say anything about it.
That's good to know, but I avoid gambling with JLC these days. PCBWay seems to have better pricing in this case anyway.
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PCBWay said:
Your design includes half-holes, but the portion of the half-hole inside the board edge is less than 0.25mm. To meet our manufacturing requirements, we recommend increasing the hole diameter or adjusting the hole position to ensure there is at least 0.25mm of the hole remaining inside the board.
I will fix that and upload a new gerber set.
Thanks,
Josh
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Here's the updated gerber set.
USE AT YOUR OWN RISK.
Thanks,
Josh
ETA: This version passed review at PCBWay.