Advantest R3463 trouble (solved) - Page 1
Forum section: electronics / repair

author: Maurizio1957
author_rank: Contributor
timestamp: October 14, 2022, 02:34:19 pm
content: Hi all, what do you think about a R3463 spectrum analyzer that does not start until 24 - 48 hours have passed since the last start? (excluding 'when it starts do not turn it off') It loads the files but the screen remains stuck on the Advantest logo...Cheers Maurizio

author: Maurizio1957
author_rank: Contributor
timestamp: October 15, 2022, 08:13:43 am
content: Preface: i'm not an electronic professional, i'm just a hobbyist .A year ago an electronic engineer friend of mine gave me a lot of non-working equipment,telling me "repairs too expensive, use them to make parts ..." including: HP 8753C (zero signal outputand keyboard not working: repaired with new YIG oscillator and keyboard rebuild) and Advantest R3463 (" don't start").I have checked the voltages of the power supply and they are ok; I have opened all the boards and there is no visible damage;before replacing all SMD electrolytic capacitors i took one apart and tested with ESR meter, and it looks good ...it starts every now and then only when it has been turned off for 1 - 2 days, and then it seems to work ...is there anyone who has had similar experiences?Tnx, Maurizio

author: rainbow
author_rank: Contributor
timestamp: October 19, 2022, 06:23:36 am
content: A very lucky guy to get an HP 8753C for free ;-)First step, get the documentation:- for the R3463 there is only the Operation Manualhttps://xdevs.com/doc/Advantest/R3265A/ADV%20R3463%2C%20R3465%20Series%20Operation.pdf- but many circuits/boards are the same of the R3265 which have the fully service manual. Get it athttps://xdevs.com/doc/Advantest/R3265A/Second step, fix the power-on intermittent issue:- disconnect the power supply from the board and check it with DC load or power resistors. You should load the power supply at half the power at least.- if the power supply is working fine you need to move to the dc/dc circuits on the boards.- check if there is some back signal to the power supply that disable it to start- check all DC/DC circuits with an external power supply (regulating voltage/current)When you have resolved the power issue you can move on. Many of the Advantest's spectrum analyzer of those years have issues with compact flash and battery.

author: Maurizio1957
author_rank: Contributor
timestamp: October 19, 2022, 08:18:18 am
content: Hi rainbow, thanks for the reply! I downloaded everything and now I have something to read ...I believe the power supply is working, the voltages are in order, I have measured the output currents with a DC clamp and they are 'reasonable', I have started to test the electrolytics on the outputs of the power supply and (for now) they are ok ...Thanks again, Maurizio

author: rainbow
author_rank: Contributor
timestamp: October 19, 2022, 09:21:21 am
content: Try to understand which power line (5V, 12V, ecc.) doesn't power up or if there is some low resistance on the line voltage when doesn't power up.Good luck73

author: Maurizio1957
author_rank: Contributor
timestamp: October 20, 2022, 05:12:31 pm
content: Hi Rainbow,unfortunately it is not that easy ... the analyzer loads the operating system files, but remains stuck on the initial screen with the Advantest logo. I think the system expects a lock from some pll which doesn't happen.I checked the output voltages from the power supply and on the 25V (the voltage that feeds the main coil of the IYG) there are> 200 mV of ripple, I will try to replace the electrolytics on that branch of the power supply (the manual states 5 years of life for electrolytics, these have at least 20 ...).Ciao Maurizio

author: edpalmer42
author_rank: Super Contributor
timestamp: October 20, 2022, 07:14:52 pm
content: On my R3465, as it's booting up it shows info on the boot process in the bottom left corner of the screen. Do you see anything like that? It would give you a clue what's failing. If you don't see anything, you might have corrupt firmware or bad digital rather than RF hardware.Ed

author: rainbow
author_rank: Contributor
timestamp: October 21, 2022, 05:45:01 am
content: Quote from: Maurizio1957 on October 20, 2022, 05:12:31 pmThis is why you need to check/test power lines before everything else (also DC/DC converter in the boards).As @edpalmer42 said, if the problem is the RF part you should see some error message in the left corner or at the end of the self-test procedure.If there is something wrong in the digital part it can be: corrupted firmware (CF?) or bad SRAM, eeprom components.You should find the troubleshooting procedure in the service manual.

author: Maurizio1957
author_rank: Contributor
timestamp: October 22, 2022, 07:22:11 am
content: "You should find the troubleshooting procedure in the service manual."Hi Rainbow, I don't know how to define the troubleshooting section of the manual: ridiculous or outrageous ...the whole section is 3 pages long, it practically says: if it doesn't go, call assistance ...ok, the hunt continues ...

author: rainbow
author_rank: Contributor
timestamp: October 22, 2022, 07:34:55 am
content: R3265A service manual I has quite good troubleshooting and which voltages you need to check. As always (and correctly), the operating manual said to call the assistance.

author: Maurizio1957
author_rank: Contributor
timestamp: October 22, 2022, 07:53:22 am
content: Hi Edpalmer, yes, I see the boot process, but, when the boot is finished nothing happens and the analyzer remains blocked, Advantest logo on the screen and no error message at the bottom left.Ciao maurizio

author: edpalmer42
author_rank: Super Contributor
timestamp: October 22, 2022, 09:01:45 am
content: Remember that this is for an R3465, but here's my info from the bottom left of my screen. Some of these entries go by so fast that you'll need to make a video at 60 fps to see them. My first attempt was at about 20 fps and I missed some of them!----------------------------------------- start of display ---------------------------Read system files ...LOADING ATOS.SYSLOADING INIT.SYSSYSPATH = SD:/LOADING MONS.XLOADING GPIB.XLOADING STATUS.XLOADING REMOTE65.XLOADING SIOCTL.XLOADING ROMTASK.XLOADING DH.XLOADING VOO.XLOADING MENU.XLOADING PCCLOCK.XLOADING SYSCONF.XLOADING SRM.XLOADING ISUPER.XLOADING MMM.XLOADING CMPNSTR.XLOADING DFM.X-------------------------------------- end of display -------------------------------Does this match up with your R3463 or does the process stop somewhere?The time from power on until 'LOADING DFM.X' disappears is about 16 sec. The main display appears about 12 sec. later.

author: Maurizio1957
author_rank: Contributor
timestamp: October 26, 2022, 02:56:37 pm
content: Hi Ed, these are the files that I was able to see at power up:Read sistem files ...LOADING ATOS.SYS'' INIT.SYSSYSPATH = SD: /LOADING GPIB.X'' REMOTE & £ .X'' ROMTASK.X'' VOO.X'' MENU.X. ? (too fast).'' SRM.X'' CMPNSTR.X'' DFM.Xpause...LOADING RXSRV.X'' BASIC.Xat this point sometimes it starts, sometimes it doesn't ...lately part, but I don't know why ...Ciao Maurizio

author: edpalmer42
author_rank: Super Contributor
timestamp: October 26, 2022, 06:11:18 pm
content: So it looks like your unit completes my list (more or less) and then continues on to load other things. My R3465 has no options. Maybe yours has other options that use the extra files.RXSRV.X - maybe some kind of server process?BASIC.X - some form of the programming language called BASIC?My unit doesn't include these files at all.There is a way to copy the internal files to a compact flash card. I did it many years ago, but I don't remember how. I do remember that the info came from the users manual. If you think it would be helpful, you need a PCMCIA to Compact Flash adapter and a *small* Compact Flash card. 32 MB cards work, 64 MB cards don't work. Yes, that's MB as in MegaBytes.The adapter and Compact Flash card are also useful for saving and copying screen captures. Pick up a USB Compact Flash reader and then you can move the captures to any Windows or probably, Apple computer.FYI, I've attached a PDF that details my investigations regarding the use of Compact Flash cards.But at this point, it seems like the digital side of your unit is probably working correctly. But it seems really odd to me that there's no error message and the system just hangs.When it does boot up properly, have you checked all the outputs (30 MHz, 10 MHz, IF outputs) to make sure they're good? Have you run through the internal calibration procedure? If there is a PLL that's marginal, maybe that will retune it.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: October 27, 2022, 08:26:21 am
content: Hi And, thanks for the info.I will do other tests, but first I have to reassemble the power supply, it gets too hot out of its seat.

author: edpalmer42
author_rank: Super Contributor
timestamp: October 27, 2022, 07:17:52 pm
content: By the way, if you're feeling daring (or desperate) you could try resetting the NVRAM in case something got corrupted. But this will also wipe out the calibration data so don't try it unless you're sure that the autocal function is working!!!To reset the NVRAM, hold the "." (dot, period, whatever) key as you power the unit up. I've never done it so I don't know how long you have to hold it for or if there's a message that tells you that it's done. I'm guessing that one of the things that gets wiped is the clock.Have you checked the battery on the CPU board? If it hasn't been changed, it's probably stone dead.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: October 28, 2022, 07:13:12 am
content: Hi Ed , I apologize for the typo in my last post.The battery is new, I changed it; now I am waiting for a new set of capacitors for the power supply .My 3463 has a label with " installed option n. 09, 61, 15" but i don't know the meaning...until now I aven't read the user manual carefully ...As I said lately the analyzer starts and works apparently well, in my search for a fault I removed all 4 internal boards and the various coaxial cables between them, opened the shields and checked the inside.maybe there was a bad contact on the boards and now it works?more news will follow ...Ciao Maurizio

author: edpalmer42
author_rank: Super Contributor
timestamp: October 28, 2022, 07:59:46 am
content: When you replaced the battery you probably lost all the calibration info. The intention is that the autocal will replace it all.Option 09 = CDMA Test Source ControlOption 15 = A version of the BASIC programming language. Also called Program Loader Option. So that explains the 'BASIC.X' program that loads on boot.Option 61 = CDMA MeasurementI have manuals for Options 15 and 61. Let me know if you need them. They total about 6 MB. I don't know what the size limit is for attachments. I probably got them from the Yahoo Advantest group. It's now moved to groups.io .A bad connection is a definite possibility. Reseating cards and connectors is always a good idea for troubleshooting, even though that can cause intermittent connections. That just means that the connector needs to be cleaned.Good luck, Maurizio! Keep us informed!Ed

author: Maurizio1957
author_rank: Contributor
timestamp: October 28, 2022, 02:58:11 pm
content: a strange fact: if I disconnect the 24V line coming from the power supply,the YIG oscillator does not work, but there are no anomaly warnings ...Maurizio

author: Fraser
author_rank: Super Contributor
timestamp: October 28, 2022, 03:55:43 pm
content: Thank you to those contributing to this thread. I have an SA from this series that died after I cleaned the processor PCB that had electrolyte leakage contaminating it. I used a professional swept frequency ultrasonic tank so may have damaged crystals as wellI had removed the battery before the clean so clearly destroyed the calibration data set. Thank you for detailing the auto cal processFraser

author: Gyorgy Albert
author_rank: Contributor
timestamp: October 28, 2022, 04:15:06 pm
content: Hi fellows,Don't worry about the "calibration data" backupped in the RAM. It is the "user calibration", which is the result of connecting the CAL output to the RF input, and running the self calibration routines. This has nothing to do with the calibration data of the instrument, which is in the eeproms of each module. So this calibration data is safe, even if your battery runs out. Indeed, pressing the dot key while booting (powering up) the analyzer, is clearing the RAM, together with the user calibration data. But this does not have any effect on the performance of the analyzer. And the user calibration is a procedure which can be made as often is needed.BR,G

author: edpalmer42
author_rank: Super Contributor
timestamp: October 28, 2022, 05:14:13 pm
content: After I replaced the dead battery in my R3465, I had a lot of trouble getting the autocal process to complete successfully. My guess is that due to age and component drift the eeprom data was so out of date that the autocal process gave up. Sort of like "I've had to move things too far. This can't possibly be right!". The problems were related to levels rather than frequency or filters. The process might fail and state that the reference signal level was too low. No, it wasn't. Or later, it might say that the attenuator was bad. No, it wasn't. I had to use an amplifier and attenuator combination to *slowly* move the results. This allowed the autocal process to keep up with the changes. Eventually, after adjusting the pads and running the individual calibration routines over and over, (the unit includes both 'calibrate all' and multiple seperate calibration processes) I was able to get the unit to complete the 'calibrate all' function successfully. It was very strange!By the way, the entire autocal procedure only works on the low frequency band (9 KHz to 1.7 GHz). How do you calibrate the higher frequencies? Some Advantest spectrum analyzers have a hidden maintenance menu, but AFAIK, the R3463 and R3465 don't have that.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: November 23, 2022, 03:49:57 pm
content: Hi all,I replaced all the electrolitics in the power supply, checked all voltages are fine, reassembled all and now there is the same old problem:analyzer stuck on the Advantest logo... it load files until DFM.X, and then stop loading other files ( RXSRV.X , BASIC.X ).Now I don't know what to do anymore...Greetings, Maurizio

author: edpalmer42
author_rank: Super Contributor
timestamp: November 23, 2022, 04:25:02 pm
content: Two other thoughts ......If it always hangs when loading BASIC.X, that won't have anything to do with the RF section. But since it always gets that far, it suggests that the digital section is somewhat working. During the boot process, it's copying those files into RAM so maybe you've got a flaky RAM chip. When the system tries to load BASIC.X, it happens to write to a bad address and hangs the system. It works after being off for 24 - 48 hours because it's nice and cool. Try freeze spray and a heat gun to see if you can find one bad memory chip.I had a problem on my R3465 where the trace was about 2 divisions wide. It turned out to be a bad surface-mount electrolytic capacitor on the RF deck. I started checking other similar capacitors and found that a bunch of them had high ESR. Maybe some of the electrolytics on your CPU board have gone bad.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: November 23, 2022, 06:05:54 pm
content: < Try freeze spray and a heat gun to see if you can find one bad memory chip.Thanks Ed, I'll do!!Maurizio

author: Maurizio1957
author_rank: Contributor
timestamp: November 24, 2022, 03:47:31 pm
content: Hi Ed, you hit the bullseye! Today I tried to turn on the SA, and it didn't start; i tried heating the top 2 tabs with a hair dryer and it worked.Noise floor was higher than normal, but in a few minutes it dropped down.Faulty capacitors all around? I think I have to change them all, not only in the power supply.Ciao, Maurizio

author: Fraser
author_rank: Super Contributor
timestamp: November 24, 2022, 05:05:37 pm
content: My similar model Advantest SA had failed (leaking) electrolytic capacitors in the power supply DC-DC converters, Processor PCB and RF PCB ! Basically all of the electrolytic capacitors had either failed or were starting to fail

author: edpalmer42
author_rank: Super Contributor
timestamp: November 24, 2022, 07:21:09 pm
content: Quote from: Maurizio1957 on November 24, 2022, 03:47:31 pmWhat is a 'tab'? I don't know what that refers to.Actually, what you're describing doesn't sound right. Heating it to make it work is the opposite of what you experienced earlier. But you still might be dealing with either a bad component that has become sensitive to temperature, or maybe it's just a solder joint that has gone bad over the years. Power transistors and connector pins are famous for unsoldering themselves over time, particularly when they experience heat from the current flowing through them. I'd recommend a long, boring session with a powerful magnifying glass to inspect the solder joints near where you applied the heat and all the connectors.Have you removed the processor board completely? If not, have you checked all the mounting screws to make sure they're tight? Normally, a loose screw would cause random problems rather than the repeatable one you're seeing, but these things can be sneaky.I also see a DIP switch and a few socketed chips on the processor board. It would be a good idea to switch all the switches a few times and to ease the chips out of and back into their sockets. Also, unplug and replug all the cables. Of course, do that with power off.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: November 25, 2022, 08:41:53 am
content: hello Ed, this time Google didn't do a good translation. Tab => board...>I also see a DIP switch and a few socketed chips on the processor board. It would be a good idea to switch all the switches a few >times and to ease the chips out of and back into their sockets. Also, unplug and replug all the cables.Done.I'll do more heat/cold tests.Maurizio

author: Maurizio1957
author_rank: Contributor
timestamp: November 28, 2022, 04:21:35 pm
content: Hello everyone.I would like to know if this characteristic of the R3463 is normal or not: if I connect the 30 MHz reference to the input, and I set the input attenuator to -20 dB, -30 dB etc. I always see the peak at -10 dB, and the noise floor rises. see pictures.On the screen, the reference is always 0 dB. ( Markers off ).I would have expected to see the peak drop in steps of 10 dB, or see the reference at the top of the screen change to -10, -20 ... depending on the attenuator setting.I couldn't find anything in the manual about this.Thank you all, Maurice

author: Gyorgy Albert
author_rank: Contributor
timestamp: November 28, 2022, 05:18:58 pm
content: Hi Maurizio,Yes, what you see is normal. By default the analyzer is switching the input attenuator (at RF level) automatically, together with its internal IF Step Attenuators and IF Step Amplifiers (both at IF level). All this is calculated according to the set Ref Level. You can change the control of the input attenuator to manual (as you did), but on the IF level the Step Attenuator and Step Amplifier is still controlled automatically by the analyzer (and you cannot change them to manual control). Since you kept constant the Ref Level, but changed the input attenuator to manual, and increased the RF attenuation, the analyzer compensates this attenuation with the increase of the Step Amplifier gain (to keep the dynamic range on the screen related to the Ref Level and the number of vertical divisions multiplied with the set dB/division). And of course this increase of gain will increase the level of the noise too. This is what you see.BR,Gyorgy

author: Maurizio1957
author_rank: Contributor
timestamp: November 29, 2022, 09:13:34 am
content: Hi Gyorgy, thanks for the reply, now this is clear.Now I have another issue: I see strange peaks at narrow span, both with the 30 MHz calibrator and with an external source.These peaks seems related to the time of the span rather than the amplitude of the spanand, when I start the autocal feature I see this message:" IF Step amp failure. Pls verify external reference and setting, then repeat "I have checked the 10 MHz output on the rear panel with a o'scope, and the signal is there, I don't know what " setting " check...I have these instruments: multimeters, CRO up to 50 MHz, Marconi signal generator up to 500 MHz and another sig gen from 1,3 to 3 GHz, DG8SAQ VNA, hammers and skrewdrivers...Thanks to all, Maurizio

author: Gyorgy Albert
author_rank: Contributor
timestamp: November 29, 2022, 04:55:39 pm
content: Hi Maurizio,Normally if you don't have any problems, you should see a clean carrier in the middle of the screen, without those spurs. The spurs indicate that you have some unwanted modulation on the calibration signal, but this appears not at the generation of the cal signal (not at the BNC output). Most probably somewhere on the analyzer input path (1st IF, 2nd IF and so on). It is a typical power supply/filtering problem, and it is very common for the Advantest analyzers of that age. I also had a similar problem, which leads to user calibration errors. Please see the images below: 001,002,003 is the cal signal in different span and dB/division view (measured with a good working analyzer). In zero span, the analyzer performs like an oscilloscope, you will see the demodulated signal. You can see, in zero span it is a straight line, there is no noise over it. The zero span is very handy, to determine the cause of the spurs/noise. In the pictures B004 through B007 there are the captures of the same calibration signal taken with my defective analyzer (Advantest R3273). In zero span, with 10 dB/division it also can be seen (this should be a straight horizontal line) that there is a ripple. In the last picture I triggered to the video signal (the resolution is 0.5dB/division), so it looks like an oscilloscope image, and is clear that there is an additional modulation detected, the period can even be measured with the help of the markers (the power supply is a switching mode one, so we do not chase 50 Hz or harmonics, the frequency is in the range of multiple of 10kHz). In the end the solution was to replace a lot of capacitors, first all inside the power supply, and also some others in the different modules.If you have the possibility to use another analyzer, and measure the signal on the receiver path of your R3463, you can trace down where the most part of this noise appears on the path. You have to keep the analyzer with zero span (tuned to 20/30 MHz, depending on the analyzer, and the CAL signal connected to its input), and you can measure along the path (1st IF, 2nd IF, etc.) with the other analyzer the signal (also in zero span). You will find where this additional modulation appears.This unwanted modulation causes the step amplifier/attenuator calibration failure. During the user calibration, when the IF is calibrated, the analyzer keeps the input RF attenuator at fixed value, and switches some IF step amplifiers and attenuators with small increments (0.1/0.2/0.4/0.8 dB). As it can be seen in images the ripple causes a change in amplitude of the demodulated signal more than 1 dB, which confuses the analyzers measurement/calibration routine. It measures a reference level first, makes a small attenuator step change, and when measures again, due to the ripple, it will detect an over range value. So it will report an error.

author: Gyorgy Albert
author_rank: Contributor
timestamp: November 29, 2022, 05:16:17 pm
content: Hi all,I am following this topic, because I also have an Advantest R3272, which belongs to the same family as the R3463/R3465. The platform is the same, the RF decks of the units are different (3GHz/8GHz and 26.5 GHz version). I was a bit annoyed because I have never seen a R3272 with the Basic controller options, or the RX control options, which makes the R3560 family controllable by the analyzer. And I would be interested to enable this option for my analyzer. I recorded the boot sequence (indeed, 60 frames was necessary to not miss anything, thanks Ed), and I noticed the following differences in my unit compared to what is listed by Ed and Maurizio:Read system files ... >> OKLOADING ATOS.SYS >> OKLOADING INIT.SYS >> OKSYSPATH = SD:/ >> OKLOADING MONS.X >> missingLOADING GPIB.X >> OKLOADING STATUS.X >> OKLOADING REMOTE65.X >> in my case is REMOTE72.XLOADING SIOCTL.X >> OKLOADING ROMTASK.X >> OKLOADING DH.X >> missingLOADING VOO.X >> OKLOADING MENU.X >> OKLOADING PCCLOCK.X >> OKLOADING SYSCONF.X >> missingLOADING SRM.X >> OKLOADING ISUPER.X >> OKLOADING MMM.X >> missingLOADING CMPNSTR.X >> OKLOADING DFM.X >> OKSo obviously there are some differences. Ed wrote earlier, that the system files (these above) can be copied to the memory card. I have not found any information related to this, I checked all the user manuals (R3463/R3465/R3272). I would really appreciate if someone can give me information, about how this can be done. I tried all the possibilities, but I did not succeeded.There is a DIP switch on the daughter board which sits over the main board (in mine the switch number 7 is in ON position, all the others are in OFF), I have not tried yet to change these settings. Maybe, some special modes (maintenance maybe) can be activated/enabled with these switches. In the case of other Advantest analyzers (R3267, R3273, R3132/R31xx), where there is a flash disk, and the content can be read/listed, there is a MAINTE.X executable/library, which is loaded at boot, and this is responsible for the maintenance mode. Since in this family this file is not listed in the boot sequence, for sure the Maintenance Mode is not available. It would be helpful if we found this out, because than we could do some service mode calibration.BR,GyorgyPS. I dumped the content of all 4 eproms of my R3272, the files are available on the Advantest list of groups io. If someone needs them, just let me know, I can send them by email, or upload here (they are not too big)

author: edpalmer42
author_rank: Super Contributor
timestamp: November 29, 2022, 11:20:03 pm
content: It was many years ago that I copied those files. I didn't think I'd ever need to do it again so I didn't take any notes. I seem to remember that it felt like a bit of a hack. I know it was related to the path listed in the bootup info so probably SD:/ . It was something like 'copy all from SD:/ to A:' where A: is the PCMCIA (or Compact Flash or even SD card via adapters). I'll see if I can reinvent that wheel, but it'll take me a day or two.Ed

author: Maurizio1957
author_rank: Contributor
timestamp: December 29, 2022, 04:07:38 pm
content: After a long stop I'm restart work on this SA...I removed the lower board for capacitors check I'll do in the next few days , here I have some pictures.

author: Maurizio1957
author_rank: Contributor
timestamp: December 29, 2022, 04:18:53 pm
content: More pictures...A question: why there are on the same board SMD and through hole capacitors?Happy new year to all by Maurizio!!

author: Maurizio1957
author_rank: Contributor
timestamp: February 22, 2023, 09:25:30 am
content: Hi all,update:changed all the electrolitic capacitors in thepower supply and all the boards of the device with newsmd (where possible) or through hole capacitors;currently the problem of blocking on start-up seems to have been resolved, the SA starts regularly;the self-test passes without problems, previously it gave an error on the input attenuator oron the medium frequency channel;the problem remains on strange artifacts seen using a very narrow rbw,I did a test by listening to the mid-frequency output with an ssb receiverto 21.400 MHz, and I hear a hum that may coincide with the peaks you seeon the screen ( some pll doesn't work well, I think) , now I don't have theinstrumentation to do this check on the medium frequency of 421 MHz.The images are made with a scan time of 1 second and 5 seconds.Cheers, Maurizio

author: Gyorgy Albert
author_rank: Contributor
timestamp: February 22, 2023, 09:54:45 am
content: Hi Maurizio,Try to brake the IF stages and instead of using the IF output from the previous higher frequency stage, inject signal from an external signal generator. You can do this on both 21.4 and 421 MHz. You should be able to determine from where is coming this extra modulation. On zero span with trigger on video, you should see demodulated signal. The extra modulation should be visible there.There is also a high frequency 1st IF (above 3 GHz) for the low band of these spectrum analyzer family (in your R3463 this is the only high frequency path, since it is the 3 GHz version). The LO for this is usually made with an ERA monolithic amp, which usually fails. But the PLL of this oscillator could also cause the trouble (the free running frequency of this oscillator is detuning in time, because of the aging of the substrate material, and the locked PLL tuning voltage could be on the limit).The loop circuits of the first microwave oscillator (YIG) is quite complicated, you should isolate the problem, and it would be great if not this one is faulty.There are some topics here on eevblog about the oscillator with the ERA, the R3272/R3463/R3465 is very similar to the R3267/R3273 family (and some circuit solutions are shared also in the R132/R3162 family):https://www.eevblog.com/forum/repair/advantest-r3273-r3267-repair/25/https://www.eevblog.com/forum/repair/advantech-r3162-frequency-drift-rf-test-fail/BR,Gyorgy

author: Maurizio1957
author_rank: Contributor
timestamp: February 24, 2023, 04:40:17 pm
content: Hi Gyorgy, I did as you said and maybe I found the problem!In photo 4 I have injected a 21.400 MHz signal into the third medium frequency channel:there are no traces of anomalous signals;in photos 1 and 2 I enter with a 421 MHz signal in the second medium frequency channel:I see the usual peaks as they appear when viewing a signal with narrow RBW placedat the input to the SA, like in photo 3.So the problem could be in the 400 MHz local oscillator for the third medium frequency conversion!Stay tuned...

author: Gyorgy Albert
author_rank: Contributor
timestamp: February 24, 2023, 06:08:45 pm
content: Hi Maurizio,Good that you made progress. The mixer which receives the 421 MHz IF signal is in the middle screened compartment of the RF deck ( see your picture above, where you have noted 421MHz PANN POST). One of the side SMB connectors receives from the synthetizer module the LO signal. It is in fact 200 MHz, and there is a doubler inside the middle compartment (and some filters of course), so it will drive the mixer with 400 MHz.If you suspect the 400 MHz LO, you can use the same idea, and drive the doubler instead of the signal from the synthe with an external signal with the same level. It would be a good idea to use tye same reference frequency for the R3463 and your RF generator. Either use the 10 MHz ref output from the SA, and connect it to the ref input of the generator, either reverse way.Just one remark. I am sure that it is obviously clear, but the only variable frequency oscillator is the YIG, for the first mixer ( in fact, in the first LO loop circuit there are several variable frequency oscillators, but from the system point if view we can consider that only the YIG has variable frequency). All others LO-s have fixed frequencies. So if you broke the path, and entered external IF signals (21.4 MHz, 421 MHz), it does not matter which center frequencies you set from the SA front panel. I suppose that you set the 21.4 MHz and the 421 MHz, just to visualize clearly on the pictures which of the IF paths are tested. Right?Best regards,Gyorgy

author: Maurizio1957
author_rank: Contributor
timestamp: March 21, 2023, 04:36:49 pm
content: Hi to allafter a lot of work I think I have solved the problems of this device.The pulses that are in photos n.1, 2, 3 were caused by the 200 MHz oscillator slightly out of frequency.I made these tests: entering from the rear EXT REF 10 MHz IN/OUT with a signal from a Leo Bodnar GPSDO and varyingthe frequency of a few Hz the pulses on the screen increased with a lower frequency or decreased with a frequencyhigher than 10 MHz.I disassembled the PLL board for the n-th time and I tried to slightly move the trimmers of the vco at 200 MHz, and these pulses aredisappeared... maybe it was just a oxidized contact??? I don't know...Now everything works fine!Greetings, Maurizio