EEVBlog #823 - Rigol DSG815 RF Signal Generator Teardown

hi welcome to tear down Tuesday today we're gonna take a look at the rai gold ESG eight one five signal generator as opposed to a function generator and if you don't know the difference a signal generator is like a proper analog in this case RF signal generator from nine till it hurts to 1.5 gigahertz whereas a function generator these days is typically almost all of them direct digital synthesis they're a digital generator and actually generate the waveform with a digital to analog converter this thing doesn't do it it's a proper RF signal generator and has these specs to match so we'll take a look inside it's going to be lots of analog e RF type goodness beauty and thanks to the local Australian distributor John South Adam Ono you've seen on the blog before loaned me this little puppy for teardown and possibly will ever play around with it too but we're just doing a teardown today and this is the 1.5 gig model the eight one five there's also the 830 which is a three gig bandwidth model that I believe is the only difference this one is about two grand u.s. street price which is not too bad for an RF signal generator of these sort of specs and the three gig version is about 3600 US bucks our street price so looks all kind of funky with these big rubber surrounds on them and very nice if you have to work if well if you're gonna say if you have to drop it if you did accidentally drop it because it'll stop look none of the the RF connector and the knobs and everything don't actually protrude from the rubber but you know which is great if it falls on its face but otherwise like here you can see the way the shadowing of the light and stuff like that not a big deal but mate you know that's just a my studio lights here up on the roof behind me that are doing that but yeah they do protrude just a little bit too far but you can take them off you can unscrew them no big deal we've got ourselves a nice big ass in connector of course there's the low-frequency output as well for app modulation because you can do all sorts of modulation and stuff like that the keys on it are angled check those out so you know like you actually pushed them down you know push them in I can't actually push that in its like down like that which is rather interesting a little bit disconcerting at first but I guess I'll get used to it and the function keys I don't believe this is a touchscreen they also like push out I can't push those in if I I think if I I don't know I haven't powered this thing up yet but if I don't go in if I go try to go in there like that or push it straight on its it's a weird because you generally used to pushing buttons straight on your finger goes whoop off to one side why have they done that I know I don't know and this one up here's a normal button so I was that one but they're trying to be fancy pantsy and differentiate them hmm not sure I like it I'll tell you what they're not mucking around on the back look at what you get you get the ten megahertz reference out more importantly the 10 megahertz referencing I'm not sure what oscillator would they've got inside this thing I don't think it's like an oven eyes or anything like that it's probably just a TC EXO and more importantly 10 megahertz reference in because if you've got lab of frequency reference out standards you can plug that in we've got LXi ethernet we've got USB device USB host we've got our pulse in and out external modulation signal valid which is rather interesting and trigger in I don't know what these options here are and as you can see it's quite small and compact compared to and a kind of equivalent one which is my Marconi instruments slash our arrow flicks 2023 which you've seen a teardown of as well so basically very similar performance except this one the Marconi goes a bit lower in amplitude while fair bit lower in amplitude but the rygar can go higher in amplitude I think phase noises art which is one of the big specs azar quite quite equivalent so you know look big difference anyway enough talk you know what we say you're on the eevblog don't turn it on take it apart bloody rippa and this is always the best part so satisfying of course we could have taken off that nicely but yeah we're making a statement all right here we go we may not see much except a you know big ass processor board because all the RF goodness is probably going to be inside well it should damn well be inside some shielding cans and yep well that's boring as that poo isn't it I tell you what I don't mind it it's nice and neat and tidy isn't it what are all these are there's obviously some posts in here for some option boards or something else but look I heat shrink on the co axes here very very nice attention to detail that tied them down they're not flapping around in the breeze very nice here's our power supply it's nice and shielded once again their attention to detail they've tied down the cable up here so then slide on the case the wires don't get pinched us you know it really is quite nice fan airflow wise we've got vents on the side here the fan actually pushes out this way so it's sucking all the air in through the vents on this side air over the block because any of the RS stuff that gets hot as it's basically going to be radiated from the internal block and you can see the big ass block down there so that's the fun stuff that we want to take a look at and let's have a look on the bottom whoa now one of the first things I noticed we'll check out the rest of this in a minute and of course we'll take off the die cast metal can but check it out we have a little option module there it is Oh CX oh that's an oven controlled crystal oscillator so that's nice look they've got a like a card edge directly onto the board here going right into the RF shield that is fantastic I really like that and that's what that option is in the back just plug it in very nice design thumbs up we got ourselves some PCB mount coaxial connectors right on the board coming right out of the shield that is absolutely brilliant obviously designed to go through this cutout with folded metal there very nice attention to detail so that you don't cut your wires on the potentially sharp edge there what they're for I don't know some option board on the top point I should have actually researched this before I started tearing it down anyway you can see the center line of the PCB in there and they've got the gold plating on the edges of the board too so very nice attention to detail so nothing escapes from this metal can fantastic and all this stuff outside here obviously power supply these are all going to be I don't even have to look at and they're probably triple 1/7 low dropout regulators more regulators up here everything's going to be linear and on this switch mode rubbish so it looks like we have our power coming over here that would come from a switch mode power supply it's how they get the size down of course but you won't find any switch switch mode converters on the main analog board itself either outside the can or inside the can definitely okay looking at the spec sheet this seems to be a pulse modulation option so I'm going to assume that that will fit in here having the RF coax is coming up here so that would be the modulation pulse modulation output and digital control cable probably coming up here to the board and let's pop the front panel off here it took off the rubber baby buggy bumpers there and our four screws here Oh Oh another nice design look at this there you go PCI card edge connector oh thumbs up look at that beautifully modular and the RF coming straight out of the brick beauty and I'm not even going to bother tearing that down because that's not what we're here for today we're here for the RF kin magic and the power supply looks very nice they're doing everything right look at that it's beautifully laid out they've got protection they've got a decent amount of input filtering and stuff like that very nicely spaced airflow you know some silastic to hold stuff down everything looks hunky-dory until what wha wha wha caps on brand like this is not a bottom of the I know they're trying to make a cheap ish hire a cig gin like you know performance for the price but come on you don't have to use caps on bloody caps at least they're consistent all the way through I'll give them that and eagle-eyed viewers may have gone hey Dave what's going on here with this earth pin it's just flapping around in the breeze well no it's not it's actually a right angle PCB mount job like that and yes it does actually go through the traces right down so no problems and one thing I noticed these little red permanent marker marks here noting that for all the screws and things like that not only for the screws but have a look at the chassis somebody's marked it off there and I see this all the way around this thing you know the production operators Evo you know conscientious or there it's part of their art procedure when they assemble it to actually mark off with red every screw and every cable tie and everything that they're put in even even the connectors I mean look you get it on the connectors as well yep I've plugged that in I've made sure that's okay or is that somebody else as a separate step coming around and checking it either way I'm impressed now we could go and take out all these screws willy-nilly and we will eventually but to get the actual board and the module out some of them are marked with triangles like this and if my hunch is correct they will be ones that actually go right through and actually hold the board in so have a look at that one tada yep and what those marks show is part of the system engineering approach to this thing the the CAD designer who had to do the 3d model for this RF shielding diecast I can machined aluminium can then I don't know diecast nothing is machined aluminium and they had to put these marks in so that shows that at that stage they already knew okay exactly where they were exactly where they'd go through exactly how they'd go into the chassis and everything else so very nice I know yeah that's probably the way to do it those are your CAD tools they would have designed the whole blinkin lot with all their 3d models they would have even you know used something like the Altium Designer or somehow PCB package had all the 3d modeling they would have you know done all that and yeah and there's par for the course these days okay oh shut up and here we go you get all the correct screws out and hopefully it comes out tomorrow all the been seized at the back are a bit tricky but well I so look at that completely modular all the functionality of this thing all on one board all in one big brick ah beautiful that it be some decent cost saving on that you know no multiple boards to assemble less internal wiring every Atlas assembly cost everything else so that is beautiful now tell you what not too shabby for version 1.00 maybe they reset it for the production version it have to be you have to Reese pin this for R&D Shirley and my cordless screwdriver is down in the bunker isn't it in the middle of a much much infinitely bigger teardown than this in fact it's as big as one of my benches so yeah here we go oh dear alright we've got one more pop out on the bottom I think we got it oh here we go will it live there might be a gasket no it's gonna lift straight off we're in like Flynn oh yeah look at that spot six FPGA Wow and yes we do have gaskets on the bottom now I'll have to show you some sections up close but you can see it is completely modular as all of these things are and at the complexity of it you might think well that's kind of what the complexity of a spectrum analyzer for example this is just a basic signal generator well if you've seen my arm oconee signal generator teardown today here is the block diagram for that and you can see that there is a whole bunch of stuff reverse power protection step attenuators beat frequency oscillators modulation harmonic filters everything and that's what all of these it's going to be sort of like similar we don't exactly know how rygel have implemented it because unfortunately my goal don't include a nice block diagram like this in their documentation shame on Rygel come on at least give us some technical stuff but let's have a look at a few just and point out a few interesting things now here's our RF output here and you can see this would be as per the block diagram this would be our reverse power protection and you can see the signal just jump in between the shield in the die cast I can on top and this section here and I've probably the were like the output attenuator you know a multi-step attenuator cuz this thing goes from plus 20 DB right down to minus 110 or something like a hundred and five or something like that so I mean not as it doesn't go down nearly as low as the Marconi one does but it's still pretty decent though you might be wondering how the hell does the signal get in or out of this block well it gets out you can see the break in the shield here and there's AC coupled across there but how does anything get in look it's completely shielded right around here aha that's when you got to go in here and have a look at some finer detail see these little micro vias down here that go from there to there no coincidence that they're there they're not random there's actually a trace inside they're controlled in penis trace going from this chip which will have our clothes look out in a second because there's something naughty with it not yet it runs inside so it's completely shielded between the two white cans excellent and what if naughty Rygel gone and done look mongrels they've lasered off these the part numbers on the chips and they've done these to a whole bunch of chips inside these things so they don't want us innocent engineers tearing down our products and trying to figure out how it works come on if anyone wants to bloody well reverse engineer this thing they can I mean you know it might slow down people for a few hours or a few days but it's not gonna stop him give us a break and they've done that to this thing up here next to the spot and six FPGA and you might be wondering what is the Spartan six FPGA doing in here I thought this was like entirely analogue well this is the low frequency output connector here so this is doing all the low frequency modulation and stuff like that so they're you know doing that digitally so there's going to be a DAC in there and that's probably what that puppy there is it's probably a duck gotta have a good old-fashioned T low seven four in there bloody rippa so you can see that the here's the output and then we've got our output protection 1 output attenuator and then we've got these four sections here and these are rather interesting looks like you know it's some sort of filtering maybe they're switching in different band filters or rust something like that perhaps and then next to that check this out we've got something really important in here how do you know it's really important well look at all the cutouts around it why have they done that well they're trying to eliminate thermal expansion on whatever that puppy is there or they could be something on the other side I haven't actually looked having taken the dike our scan off the other side maybe we should do that but yes that little puppy there is obviously some sort of reference or something like that that they are really taking care of the tempo with so that's nice attention to detail you don't want any thermal expansion because well you know this whole thing's gonna heat up but then when the PCB heats up it's good even if it's a top quality one you're paying for low thermal expansion board still gonna have some thermal expansion so that can actually expand the pins as well on the chip and then that can actually affect the that can add stresses to the internal die and that can affect its our performance as well so I'm a little bit surprised to actually see that in here though but nice work and there's the other side and we can see something interesting down on our isolated cut out there got ourselves two big-ass hundred and fifty am resistors they might be in parallel for a for 75 ohms and of course it's not 75 ohms impedance what they're doing is they're my look at the size of them they've got to be our heaters which is heating up that particular board so that would be our control so there that's like a little mini oven in there very nice is that our main that's funny I'm a nice alator because they've labeled that you and that is not a oscillator package is somebody can decode the SMD markings on that then please do but you know probably some voltage reference but they've gone to a lot of trouble anyway back into the action down here I'm not gonna guess at all these components I'm sure somebody will go to the trouble to take the photo of this by the way I will have high-res photos of this teardown and the board and all the sections available on eevblog comment link down below someone usually goes long and then marks all the blocks up first so yeah I'll just crowdsource that our bloody laser marked off the numbers again mongrels and then our signal travels along sorry about the shaky image I need a dolly don't I and that troubles along does some more magic heads on up here up here up up up up up and once again you can see that the signal actually goes through a shielded inner layer there with a controlled impedance trace and back to our wired a shot again and that's our modulation input that that modulation board and then bingo we've got some what a lot of people call RF voodoo it's just a distributed element filter that's its official name you can go google that i'm sure and have a look now it might look like magic until you actually realize what's going on here it's basically just a filter it's probably just a multi-stage low-pass filter and what we've got these pads here these are actually capacitors okay so that's effectively a capacitor going down to ground and then these little squiggles in here they're actually inductors so you've got a capacitor going to ground then an inductor in series and a capacitor go into the ground so it's an LC filter like that and then you would have a little bit of resistance in here Judy error control impedance trace and it's basically just an LC filter that's pretty much all it is and they're doing a similar thing down here but there can actually be subtle differences between the geometry of these things you'll notice this one has a capacitor going down to ground but there's also an inductor in series okay and you'll see that they're different shapes that means they're different values and then just the tiny little bit even that little trace connect in there connecting to that you know that could be a resistor in series tiny little bit of inductance and there's actually you know there's many different types and I should actually have to link in some examples of these things and you can actually see there's little subtle differences between how you implement this it depends on the dielectric material the board the type of material the dielectric constant and the years width of the trace and the distance all sorts of things and there can be subtle differences you can implement all sorts of unusual filter bandpass and other type of our arrangements using these distributed element filters and what do they do it because hey it's cheap and easy in this software programs to spit these things out I mean the board's not cheap you want to have a nice you know controlled impedance controlled dielectric board and you know not just your regular Joe Bloggs you know fr4 from you know one hung low manufacturer they would have specifically chosen the board material exactly for their purposes and there's our advanced art programs you can get to actually calculate and design all these our filters for you so there's a whole bunch of stuff going on there and this looks like it's probably a some sort a mixer or something like that perhaps package it's not the oscillator I think I can get a part number on that hang on and there you have it that's a Zen calm math 364 zero the crow series cathode ray oscilloscope thank you very much it's a voltage controlled oscillator VCO and right up here next to the oven controlled oscillator cottage connector bingo there is our main oscillator 2 ppm general accuracy but of course you plug in the oven controlled oscillator and it's you know parts per billion and interestingly in addition to the spartan 6 fpga right near the low frequency output here we've got a aktel pro ASIC three of PGA so what the hell you know unusual mix there that's really bizarre anyway I'm here's some of the output type protection as well as chock-a-block in there check it out that's a laser removed the markings yet again the mongrels generally speaking on the other side of the board here pretty much just all passives nothing much doing there huge amounts I won't go into detail once again high-res photos of both sides of this board available on the website if you want to check it out but there you go that's what's inside an RF section this is what you're paying for it's all you know analog RF magic there's these parts are very expensive you can't skimp on you know a good lot of these art parts they have to come from specific manufacturers and they cost you know 50 bucks a pop or something like that and that's why you can't make one of these things for a couple of hundred dollars you know you just can't do it you've got to get the reputable parts you can't just get ripoff parts from somewhere it doesn't work you don't get the performance but overall I'm quite impressed by that because rygel are not known for their arm RF stuff but they're certainly getting into it and this is a pretty decent implementation a physical design implementation no in fact it's really very nice Shane we a block diagram for it that would have been not really nice but yeah if you sit down for a you know an hour or two you might be able to figure out what all the blocks and all the parts do and things like that but yet they've really gone to town a lot of design effort has gone into this thing and it's got reasonable specs as well they're not gonna you know they're not lead they're not industry-leading are specs by any stretch of the imagination but you know you get reasonable performance for the price that's for sure and the design quality build quality it looks like they've got someone there who knows what they're doing now if you're going to buy one of these by the way or you know any similar sort of RF product like this it's nice to do a teardown like this but if you're after especially if you buy a really ultra high-end spectra duct you don't want to be go general e taking off the RF cans because it could actually affect very minutely but could actually affect the low level of our performance of this thing so it might be likely that my goal might have to or might you know just as matter of course actually resend this back out for calibration once I'm done with this taking off because you know the torque of the screws on there and the gaskets can affect the you know the shield in between art sections and things like that so yeah you're probably especially like probably not on this one but you know some of the more ultra high-end ones definitely can have a real impact indoor right why not because well we didn't see the main processor I know there's lots of processor aficionados out there there it is Freescale IMX 283 one of these whiz-bang you know what is it six eight hundred megahertz for two megahertz or something application processors you know high end arm it's got all sorts of stuff built in it's got all the LCD drivers it's got everything else there's no LCD ribbon going out there and there's our front panel touch as well and not much else doing and of course we have our JTAG interface there and I don't see I usually get like a serial debug port on these things as well but I don't see that doesn't neither of those look like a serial debug port so you know usually you boot you can boot these things up hook up a you know regular pet to a PC serial port and have a look at all the boot you know console information as the thing our boots whatever OS its using but it doesn't seem to be one here and a sneak a little 805 one in there doing something with our PCI interface PCI connector interface mostly PCI you know standard or anything but yeah they're using the PCI connector something going over to that main board works haven't actually powered up the thing I don't even know if it worked out on the box I literally tore it down didn't turn it on I took it apart so let's plug it in it takes about 50 watts so it's reasonably power-hungry little beast let's plug her in universal voltage of course don't know what it takes on standby it should actually test it hey we know we're not chicken dinner here we go how long does it take to boot local booting yeah anyway hey we're in like Flynn there it is what citrate beauty all right let's plug it in and see if we can actually get something out of the puppy this won't be a review or a comprehensive test at all but look I got a nice RF cable with it this doesn't actually this doesn't usually come with it I don't believe but yeah comes with its own spec sheet and everything beauty and speaking of which for you i cal cert aficionados I know you're out there there we go yes it does come standard with a cow certificate Beauty tell you what I don't mind the interface at all you know you've got your frequency what you want your level what you want by default it's one gig and minus 20 yard DBM and the RF output we can just switch off our on here and then we can just switch our modulation offer on and our low frequency as well and then we can set it up we're gonna numeric keypad and we've got a real fear Deacon knob so if we got the frequency here oh there we go where's the marker where's the marker yeah there we go we've got a dot above it but it wasn't obvious at first glance it should have been you know but yeah it wasn't why is the dot not up there permantly huh and here it is and this will not be a performance test by any stretch of the imagination but I'm just showing you I've got the frequency at well the level actually I'm going to change to 0 DBM it was minus 2 but there you go it's off by about 2.9 to DBM point 9 DBM or there abouts I think the specs about half DBM on the C Jen don't quote me on that but then you've got that you know the scope as well whatever there's our carrier we've got a one gig carrier and here there is a our two key harmonica that thing and 2.5 as well that's one gig at minus 10 DBM and let's go down lower and that's down at minus 50 DBM carrier and there's a minus 10 DB 1 gig carry out with some basic sine wave amplitude modulation there at what are we got set up 10 kilohertz so easy peasy and if I change the depth down to 1% there on our modulation bingo it all works so I didn't break anything that's the main thing might I worked it out a cow a little bit half Abby's dick so yeah you've got a whole bunch of modulation there I am FM pulse modulation and there's options for that we can do sweeps as well that's very nice and well we've got our level in a frequency it's all very nice to use turn your modulation off a non-tenure F off and on Beauty Bob's your uncle what more do you want so there you go I hope you enjoy it a look inside this Rygaard ESG eight one five and a puff and the caps on caps it's a pretty decent art design and build quality it looks like so definitely a thumbs up to that puff from the caps which is a thumbs down that's par for the course these days but yeah when you're paying two grand for you know a cig gin like this you know you expect Nietzsche kana some of it you know Panasonic some quality caps in there at least come on don't skip I know you probably bought them caps on ones by the zillion I mean people are gonna say why harp on about the caps I don't know this is the only thing I really found wrong with the inside the thing um it really is quite nice so I haven't actually compared the specs on this thing compared to others on the market bang per buck I don't know yet I haven't investigated this is not a review this was just a teardown and I hope you enjoyed it if you did please give it a big thumbs up and discuss it in the comments and links and as I said before high res teardown photos on eevblog comm linked in down below unless you're already watching this video on eevblog comm in which case you already know the links are there catch you next time [Music] you

Channel: EEVblog

Views: 63,623

Keywords: Signal Generator, rigol, dsg815, dsg830, rf, function generator

Id: iI5DmU7g32A

Length: 32min 10sec (1930 seconds)

Published: Wed Nov 25 2015