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
Amplitudemodulationsweep too ?
SSG3021X can do and you can set up some eye catching effects for exhibitions.
You have to do a video to really show that effect.
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
Quote10kHz: 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?
My DAQ6510 seems to be the best option
Hi,QuoteMy 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. :-//
It took 24 minutes to update the firmware, which was hilarious because the SML says FASTLOAD on the screen the whole time.
500MHz 176mV
600MHz 136mV
Hi,Thanks! It's running now. 😉
Congrats... ;)
Now do a sweep....
That could be right; the -3dB point of the scope is somewhere between the two frequencies.That's what I assumed...and why I put an offer on an RF power meter. 😉😉
Taking 220mV as a basis, that would be 220mV* 0.707, or approximately 155.5 mV.
Have you tried other coax cables ... I find they vary some at the higher frequencies.
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?
The stock fan has a higher pitch noise, that is more annoying than the Noctua fan ....
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!
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)
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.
That's still brand new; my SML01 had over 100,000 hours on it. ;)
(No joke)
Hi, sorry I haven't spoken for a long time.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.
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)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.
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.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.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.
Unfortunately, even R&S no longer seem to have this software, at least here in Germany...
Hi,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.
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?Measured on:
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.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.
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.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.
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.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.
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.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. 😉
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.
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.
Yesterday I was playing with the pulse generator "video out" which directly outputs the set pulse. Today, I played with the pulse modulation.1st grade simple stuff ! :P
Messing with these settings also helped improve my triggering skills, which was a nice bonus. 😉
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:
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
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
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 would need to dig into complete specs of that generator but keep in mind that there are several factors:M&P connectors and Hyperflex 5 cable used for the tests.
- 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).
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.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.
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 ;)Let's stay just shy of that rabbit hole. 😉
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
Hi, do you have similar noise floor without averaging on SDS3000?Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
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
Hi, do you have similar noise floor without averaging on SDS3000?Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
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.....
A Peak Hold setting might account for that.Hi, do you have similar noise floor without averaging on SDS3000?Maybe they might chose to display the Siglent FFT menus for you to examine the many ways FFT can be configured.....
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
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 ? :-//
:-+
now this is a proper noise floor - congrats
just one question - is this taken with SDS2000x hd series or your 5000x scope?
:-+
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. 😉
Means that noise floor is pretty good on 2000 and 3000 series and that is valueable info for me - Many thanks!
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
I'll put up some examples of 50 MHz FFT with a few scopes in the next day or so,50 MHz 0dBm FFT tests with 50 MHz span using SSG3021X only...too much dicking around with cabling otherwise. :horse:SDG6000X andSSG3000X will be the source.
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
Has anyone been able to find a replacement display for this generator?
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.
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.
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.
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.
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 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
Well, looks like that fixed it. B3 is the problem, now time to investigate why.
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.
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.
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.
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:
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.
Datasheet attached.
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.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.
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. ;)
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.
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.
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.
Somebody else please verify.
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: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?
- 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+
Again, I might mistaken, but please check. :)
I'm not sure. This needs translation. ;)
It sounds like you're probably correct, but it's slightly ambiguous.
I'm not sure. This needs translation. ;)
It sounds like you're probably correct, but it's slightly ambiguous.
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
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.That's good to know, but I avoid gambling with JLC these days. PCBWay seems to have better pricing in this case anyway.
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.
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.
I got myself an SML02 with some issues. So far:
1. Radom screw loose in the enclosure on arrival, falls out at the back.
2. Output level not even close, 30dB or more difference from set level and output. At least the output goes to 2.2GHz. So I'm guessing blown output amplifier. Probably also issues with some of the switch MMICs.
3. Lines on the LCD. Probably a zebra strip issue, I have to se if this can be repaired or not.
4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
I knew about 2 and 3 when buying, let's see if I can repair this.
Probably worth trying self-calibration also.
I did read through this thread. I didn't see any options listed at the back, not sure if RS does that. And I didn't have time to take it apart. That have to wait till this weekend. I hope there is an option, seemingly it uses the same switch MMICs so I would rather have a working output level than pulse generation.I got myself an SML02 with some issues. So far:
1. Radom screw loose in the enclosure on arrival, falls out at the back.
2. Output level not even close, 30dB or more difference from set level and output. At least the output goes to 2.2GHz. So I'm guessing blown output amplifier. Probably also issues with some of the switch MMICs.
3. Lines on the LCD. Probably a zebra strip issue, I have to se if this can be repaired or not.
4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
I knew about 2 and 3 when buying, let's see if I can repair this.
You might want to read about the tests I did on mine and how the output unlevel issue was interestingly just a module. You didn't mention if it has any other installed options though, so my experiences might not be worth much.
On the other hand, can you set up a slow sweep from 9kHz - 2.2GHz and leave trace persistence ON on the SA for the test? I am curious to see if the gain error is flat.
The other thing, is you might want to do a self-test. If it passes, the output amp is probably fine, and something else in the path is broken. Mine did this, and all self-tests passed but the B3 pulse mod option was busted. When bypassed, it had no issue on the output.
4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
I did read through this thread. I didn't see any options listed at the back, not sure if RS does that. And I didn't have time to take it apart. That have to wait till this weekend. I hope there is an option, seemingly it uses the same switch MMICs so I would rather have a working output level than pulse generation.I got myself an SML02 with some issues. So far:
1. Radom screw loose in the enclosure on arrival, falls out at the back.
2. Output level not even close, 30dB or more difference from set level and output. At least the output goes to 2.2GHz. So I'm guessing blown output amplifier. Probably also issues with some of the switch MMICs.
3. Lines on the LCD. Probably a zebra strip issue, I have to se if this can be repaired or not.
4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
I knew about 2 and 3 when buying, let's see if I can repair this.
You might want to read about the tests I did on mine and how the output unlevel issue was interestingly just a module. You didn't mention if it has any other installed options though, so my experiences might not be worth much.
On the other hand, can you set up a slow sweep from 9kHz - 2.2GHz and leave trace persistence ON on the SA for the test? I am curious to see if the gain error is flat.
The other thing, is you might want to do a self-test. If it passes, the output amp is probably fine, and something else in the path is broken. Mine did this, and all self-tests passed but the B3 pulse mod option was busted. When bypassed, it had no issue on the output.
I also made a quick scan, measuring the output level at different frequencies and it seemed mostly consistent. I've also saw sometimes 2nd order harmonics (as I recall) 20-30 down, which would mean I think that filter is getting bypassed, maybe a stuck MMIC.
Shahriar from TSP had a few repairs where it was the output cabling, I don't think I'm that lucky, but we will see. The test you suggests make sense.
Also, when looking at this thread before buying the SML02, I noticed that the manual's block diagram and the teardown photo KungFuJosh posted, they don't seem to align 100%. I'm not sure how exactly, but the switches seem to do something different than what's in the manual.
You can buy 'stickers' from Buttonworx which have a conductive pattern printed on them. They go between the original rubber key mat and the contact area. They work like a charm.4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
This is a known problem with older SML. From what I hear it is the contact pill in the elastomeric keypad that degrades. I know that some people have experimented with conductive silver, but that is apparently difficult to fix. Luckily, mine doesn't do that.
Interesting. I've google searched for this quickly and it also gave me an alibaba link as well.You can buy 'stickers' from Buttonworx which have a conductive pattern printed on them. They go between the original rubber key mat and the contact area. They work like a charm.4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
This is a known problem with older SML. From what I hear it is the contact pill in the elastomeric keypad that degrades. I know that some people have experimented with conductive silver, but that is apparently difficult to fix. Luckily, mine doesn't do that.
This is interesting, when you mention the harmonics. They should not appear that high relative to the carrier. This is almost the exact same issue from my B3 pulse modulation option, where the switch MMIC died and one of the output amplifiers was also broken according to test points.I also though so. I have low frequency output and modulation input, which might be an option (not shown on the picture). Anyway, I'll crack it open and see what's inside. And I really apricate the help.
Not entirely sure what components were all broken on the B3, as I bypassed it and called it a day. I am hoping to swap the switches out at some point, though.
Table 7-1 Frequency schedule of Output Unit 2 GHz / 3 GHzThis seems to be the biggest difference between the SML02 and SML03, maybe the 02 doesn't have the 2nd and 3rd filter.
n Input frequency Output frequency
2 605.25 to 909 MHz 1210.5 to 1818 MHz
3 606 to 885 MHz 1818 to 2655 MHz
4 663.75 to 825 MHz 2655 to 3300 MHz
The selection of the desired spectral line is made by means of a tunable, three-stage bandpass filter
which can be set to the desired frequency via a D/A converter using calibration data stored in the
instrument. This filter suppresses unwanted spurious, i.e. adjacent spectral lines from the step-recovery
diode, down to -60 dBc. The filter frequency ranges are specified as follows:
Table 7-2 Filter frequency ranges
Filter Frequency range
1 1210.5 to 2200 MHz
2 2200 to 2800 MHz
3 2800 to 3300 MHz
:DIAGnostic[:MEASure]:POINt?Service manual tells me to run the software. >:(
The command triggers a measurement at a measuring point and returns the voltage measured.
The measuring point is specified by a numeric suffix (cf. service manual).
Example: :DIAG:MEAS:POIN? 2 Response: 11.56
Interesting. I've google searched for this quickly and it also gave me an alibaba link as well.You can buy 'stickers' from Buttonworx which have a conductive pattern printed on them. They go between the original rubber key mat and the contact area. They work like a charm.4. This on is strange, very slow response to button presses. Often times I have to press a button for 2 seconds for it to register. The encoder is fast though, so not sure what's going on.
This is a known problem with older SML. From what I hear it is the contact pill in the elastomeric keypad that degrades. I know that some people have experimented with conductive silver, but that is apparently difficult to fix. Luckily, mine doesn't do that.
Searching on AliExpress, " Diameter 3/4/5/6 MM 4 Sizes Black Conductive Rubber Pads Keypad Repair Kit" is an item for ~3 EUR.This is interesting, when you mention the harmonics. They should not appear that high relative to the carrier. This is almost the exact same issue from my B3 pulse modulation option, where the switch MMIC died and one of the output amplifiers was also broken according to test points.I also though so. I have low frequency output and modulation input, which might be an option (not shown on the picture). Anyway, I'll crack it open and see what's inside. And I really apricate the help.
Not entirely sure what components were all broken on the B3, as I bypassed it and called it a day. I am hoping to swap the switches out at some point, though.
Here is some brain dump from me:
From what I can see in the manual, the difference between the SML02 and SML03 is the number of filters after the step recovery diode.QuoteTable 7-1 Frequency schedule of Output Unit 2 GHz / 3 GHzThis seems to be the biggest difference between the SML02 and SML03, maybe the 02 doesn't have the 2nd and 3rd filter.
n Input frequency Output frequency
2 605.25 to 909 MHz 1210.5 to 1818 MHz
3 606 to 885 MHz 1818 to 2655 MHz
4 663.75 to 825 MHz 2655 to 3300 MHz
The selection of the desired spectral line is made by means of a tunable, three-stage bandpass filter
which can be set to the desired frequency via a D/A converter using calibration data stored in the
instrument. This filter suppresses unwanted spurious, i.e. adjacent spectral lines from the step-recovery
diode, down to -60 dBc. The filter frequency ranges are specified as follows:
Table 7-2 Filter frequency ranges
Filter Frequency range
1 1210.5 to 2200 MHz
2 2200 to 2800 MHz
3 2800 to 3300 MHz
Anyway, first fixing.
I found on the KO4BB website an SME03 service kit, someone suggested on the groups.io to use that. It's written for windows 3.1 , there is no way to run that today unfortunately.
From what I see, there is some limited documentation on the diagnostics commands in the operation manual (SCPI commands), telling me this:Quote:DIAGnostic[:MEASure]:POINt?Service manual tells me to run the software. >:(
The command triggers a measurement at a measuring point and returns the voltage measured.
The measuring point is specified by a numeric suffix (cf. service manual).
Example: :DIAG:MEAS:POIN? 2 Response: 11.56
OK, I made some time to open it up. The output coax assembly looked strange.
I agree with that 100%. The output cable should not look like that. It needs to be replaced.OK, I made some time to open it up. The output coax assembly looked strange.
The cable shouldn't look like that. It appears somebody tried to repair it. It should be a single semi-rigid cable with the cores on it directly.
Thanks Josh, I also think so. But it looks very intentional on first sight.OK, I made some time to open it up. The output coax assembly looked strange.
The cable shouldn't look like that. It appears somebody tried to repair it. It should be a solid/single semi-rigid cable with the cores on it directly.
The B19 output cable illustrates this more easily. The front panel cable is the same idea, but shorter.
Thanks,
Josh
Thanks Josh, I also think so. But it looks very intentional on first sight.With the wrong tools, and a solid lack of skills, anything is possible. ;)
But now I've put it under the microscope, and the split looks like it broke somehow? I've never seen a broken hardline coax where it was broken on the outside.
Actually, this could be shipping damage. I ordered it to a DHL service point. The guy handed over the package by slapping it on the counter on the shorter edge of the package. It took the better half of me not to shout with him. Fragile written on the package and all...Thanks Josh, I also think so. But it looks very intentional on first sight.With the wrong tools, and a solid lack of skills, anything is possible. ;)
But now I've put it under the microscope, and the split looks like it broke somehow? I've never seen a broken hardline coax where it was broken on the outside.
Yep. Every now and then I lend a hand with test equipment repairs and you don't want to know what I've encountered so far.Thanks Josh, I also think so. But it looks very intentional on first sight.With the wrong tools, and a solid lack of skills, anything is possible. ;)
But now I've put it under the microscope, and the split looks like it broke somehow? I've never seen a broken hardline coax where it was broken on the outside.
Actually, this could be shipping damage. I ordered it to a DHL service point. The guy handed over the package by slapping it on the counter on the shorter edge of the package. It took the better half of me not to shout with him. Fragile written on the package and all...That is your problem. Equipment should be packed so it survives falling off a flight of stairs. Couriers really don't care about fragile signs etc. Just make sure equipment is packed properly. If you don't then you should accept shipping damage. I've seen a fair amount of that...
It doesn't look like it happened in shipping. The photo looks like part of the cable is semi-transparent instead of grey. Somebody botched it.You are right, this is someone's doing. Here it is compared to a high quality N to SMA connector. I hope to use this (and a semi-flex SMA-SMA cable) to fix the front connector. The center contact is a lot deeper on the SML's connector, I don't think it even makes contact at all.
If you can figure out how to reuse those cores, you'll be happy. If you can get a semi-rigid cable, and add a crimp connector, that would probably work.It doesn't look like it happened in shipping. The photo looks like part of the cable is semi-transparent instead of grey. Somebody botched it.You are right, this is someone's doing. Here it is compared to a high quality N to SMA connector. I hope to use this (and a semi-flex SMA-SMA cable) to fix the front connector. The center contact is a lot deeper on the SML's connector, I don't think it even makes contact at all.
On the good connector the center pin is 4.3mm deep, on the bad one it's 9.2mm. :scared:
On the other hand, can you set up a slow sweep from 9kHz - 2.2GHz and leave trace persistence ON on the SA for the test? I am curious to see if the gain error is flat.It is, that variation is more likely my bad quality coax.
I looked into the diagnostic menu. What jumped at me is the operation time is 900 hours, which is not a lot. And the "overload protection count" was 122 which sounds like a lot, and I'm not sure how that even happens so often to such an instrument. I'm not sure either if this is kept in the battery backed RAM and if this resets.That's nothing. 100,000 would even be considered low. That said, the number could be inaccurate.
Harmonics seem to appear only below 750MHz.That's (unfortunately) normal. The attenuator/output module is the most common failure point. You can use the switch conversion board I shared earlier in the thread if you need to replace them with something new.
I measured the output of the 2/3GHz output, which was 8.6dBm when the output was set to 0dBm. And it went all the way to 22dBm, when the output was set to maximum. So this module is working, the attenuator has the issue.
Thanks, I was also expecting this to be the issue. I've taken it apart, and found 3 switches that had the issue, and a 4th may be on it's way out. There was a lot of voltage drop on the resistor series with the IC control pin.I looked into the diagnostic menu. What jumped at me is the operation time is 900 hours, which is not a lot. And the "overload protection count" was 122 which sounds like a lot, and I'm not sure how that even happens so often to such an instrument. I'm not sure either if this is kept in the battery backed RAM and if this resets.That's nothing. 100,000 would even be considered low. That said, the number could be inaccurate.
The overload thing probably doesn't matter. I think that's automatically counted when you set the output past a specific dB level.QuoteHarmonics seem to appear only below 750MHz.That's (unfortunately) normal. The attenuator/output module is the most common failure point. You can use the switch conversion board I shared earlier in the thread if you need to replace them with something new.
I measured the output of the 2/3GHz output, which was 8.6dBm when the output was set to 0dBm. And it went all the way to 22dBm, when the output was set to maximum. So this module is working, the attenuator has the issue.
Thanks,
Josh
Some other things that I've noticed. I went through the built in testpoints (in the menu), and TP 404 and 407 was 0V. This is called MB 8VHF1, which makes me think this is supposed to be 8V, and not 0V. Can someone check it please? This is not covered in the manual.
| Diagnostic point | Description | min | max |
| 404 D_8VHF1 | Supply voltage for RF stages | 7.55 | 8.35 |
| 407 D_8VHF2 | Supply voltage for RF stages | 7.55 | 8.35 |
I found on the KO4BB website an SME03 service kit, someone suggested on the groups.io to use that. It's written for windows 3.1 , there is no way to run that today unfortunately.Out of curiosity, I tried that software on 32-bit Windows 7 and it seemed to start up fine. Maybe the software could be made to work along with a recent NI-VISA installation and a PCI-E (i.e. something recent enough that has a 32-bit Windows 7 driver) GPIB adapter.
Thanks. I just found out that the service manual comes in two volumes and I only found volume 2 so far. But Volume 1 was on Elektrotanya.Some other things that I've noticed. I went through the built in testpoints (in the menu), and TP 404 and 407 was 0V. This is called MB 8VHF1, which makes me think this is supposed to be 8V, and not 0V. Can someone check it please? This is not covered in the manual.
According to the service manual:
Diagnostic point Description min max 404 D_8VHF1 Supply voltage for RF stages 7.55 8.35 407 D_8VHF2 Supply voltage for RF stages 7.55 8.35
Both test points belong to the output module. The manual says "Check 8-V voltage regulator N21, V146" and "Check 8-V voltage regulator N21, V234" when these are out of tolerance.
The different attenuator pads of 5, 10, 15, 30, 40dB permit to set the attenuation inThe 5 groups makes no sense with the layout that we have.
the range from 0 to 125dB with 5-dB resolution. The attenuator pads are combined
in 5 groups and switched with GaAs switches.
The IC I swapped to the input of the attenuator was also toast, so I went in an other direction with the repair, hacking in another switch IC. So this apparently works.
That trace is in max hold, that' why there is something every 100MHz. I got 17dBm max out of the 19 nominal. The difficulty of hacking in this IC is quite high, but I wanted to test it before committing more effort of making an adapter PCB. Sorry for the upside down generator in the picture, but it's this way. The generator was set to 5dBm.
The IC is MASW-007935.
I had the adjustment programWhich one? SME03 or something else? Do you still have it?
Interesting. I have an SML02, not 03. So the frequency is limited.*The IC I swapped to the input of the attenuator was also toast, so I went in an other direction with the repair, hacking in another switch IC. So this apparently works.
That trace is in max hold, that' why there is something every 100MHz. I got 17dBm max out of the 19 nominal. The difficulty of hacking in this IC is quite high, but I wanted to test it before committing more effort of making an adapter PCB. Sorry for the upside down generator in the picture, but it's this way. The generator was set to 5dBm.
The IC is MASW-007935.
In the past as an experiment, i tried making an tiny carrier board to replace the existing switches marked W1 on the attenuator to something modern, it worked sort off, since I had the adjustment program, NRVD and NRV-Z51, even adjusted the unit. Problem was I could not get the frequency level response linear above 2GHz, main reason likely the carrier board was FR4, 1.6mm, with limited space, re-routing rf traces becomes a hasle and noisy, could have performed better with a better pcb material and thinner board. But it was a weekend experiment.
Problem was I could not get the frequency level response linear above 2GHz, main reason likely the carrier board was FR4, 1.6mm, with limited space, re-routing rf traces becomes a hasle and noisy, could have performed better with a better pcb material and thinner board. But it was a weekend experiment.
*Though from what I can see maybe there isn't any hardware difference between these two types.
It's a great guess, but it's only part of it.*Though from what I can see maybe there isn't any hardware difference between these two types.
There might be something as stupid as jumpers that set the top frequency in the 2G/3G module. I never tried them though, since all the units I had were 3GHz. They use the same module for both units, so I dunno if they bothered to change anything else or not.
Admittedly, it's a dumb guess, but what do those jumpers do? 🤔
*Though from what I can see maybe there isn't any hardware difference between these two types.
There might be something as stupid as jumpers that set the top frequency in the 2G/3G module. I never tried them though, since all the units I had were 3GHz. They use the same module for both units, so I dunno if they bothered to change anything else or not.
Admittedly, it's a dumb guess, but what do those jumpers do? 🤔
0000: 05 00 2C 00 CE 47 10 00 00 20 00 00 C7 61 A6 00 |..,..G... ...a..|
0010: 02 00 95 01 CA 7E F9 05 BC 2A 00 00 CA 00 4F 50 |....~...*....OP|
0020: 55 33 00 00 00 00 00 00 00 00 00 00 64 00 1C 00 |U3..........d...|
0030: 80 FF 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
0040: 00 00 00 00 00 00 00 00 FF FF 00 00 FF FF FF FF |................|The jumper X2 seems to set the middle pin either to the SDA, or GND. Considering that SDA would be pulled up most of the time, I guess this is just to select 3.3V or GND on something.
Have you tried running the self calibration after changing the jumpers?I'll fix the attenuator first, before doing any sort of calibration. I think half the steps aren't working properly. Then I'll do one without changing the jumpers to make sure my procedure is right.
Problem was I could not get the frequency level response linear above 2GHz, main reason likely the carrier board was FR4, 1.6mm, with limited space, re-routing rf traces becomes a hasle and noisy, could have performed better with a better pcb material and thinner board. But it was a weekend experiment.
Another reason could be that the adapter board compromises the impedance matching between switch and transmission line, leading to reflections which cause ripple. Also, the electrical length of the lines may have been slightly changed. If the circuit relies on phase matching, this might also lead to ripple.
Edit: The layout might also compensate for the SO-8 pin of the original switch by matching elements in the layout (e.g., trace thickness). This may be upset by the adapter board, even if you try to stick to 50 ohms impedance as close as you can.
I had the adjustment programWhich one? SME03 or something else? Do you still have it?
Thanks,
Josh
Do you mind sharing the gerbers? I shared gerbers previously for a different option as well.Sure, I wanted to test is a bit to make sure it works. I'll gather the files and make a github repo for it when I have time.
1) Figuring out if I can control my SA and the SML02 over SCPI
2) Figuring out to change calibration values over SCPI
3) Getting the right RBW/VBW values
4) Wishing that I had a power meter
5) calibrate the RF cable
6) Writing python script to calibrate it, or vibe code it
Sounds easy ;D