Author Topic: Advantest R3477 9kHz to 13GHz spectrum analyzer  (Read 14540 times)

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Online nctnico

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Advantest R3477 9kHz to 13GHz spectrum analyzer
« on: July 12, 2016, 10:36:22 pm »
A short play with my latest toy: an Advantest R3477 9kHz to 13GHz signal analyzer spectrum analyzer which I got from Korea though Ebay for $1400 ex. shipping. All the recent talk about spectrum analysers made me want to upgrade my Advantest R3131 (9kHz to 3GHz with monochrome screen) to something with a color screen and preferably the ability to write screendumps to a USB stick. After some hunting on Ebay I found the R3477 but since it is called a signal analyzer instead of a spectrum analyzer it might fly under the radar of people looking for a spectrum analyzer. It seems several Korean sellers are unloading a whole bunch of these machines so this may be a good opportunity to get a good deal. However it does not (seem to) have typical EMC measurements like quasi peak detection but so far I have not really needed that for EMC pre-compliance testing. BTW I didn't look specifically for a spectrum analyzer from Advantest but it turned out my third spectrum analyzer is from Advantest as well. I also didn't need anything over 3GHz but getting more is never a deal breaker.
Front:

Rear:


This machine is based on a PC (Pentium 3 AFAIK) and it runs Windows XP embedded. It has a 800x600 TFT touch screen. Unfortunately the touch screen in my one is (was?) slightly damaged which made the pointer to stick in one spot. I think it is easy to replace (it is just cheap resistive touch screen) but first I tried to heat it a little with some hot air and that seemed to have done the trick. Deformed plastic usually goes into it's original shape when heated (think about heat shrink tubing) so a dent in the plastic film could just level out enough. Due to the internal PC it does use quite a lot of power so it needs lots of airflow and thus the R3477 produces a significant amount of fan noise.

A disadvantage is that this spectrum analyzer doesn't have internal DC blocking capacitors so for general purpose use I ordered a DC blocker just to be safe.

Time for some play. First a 3GHz carrier with a 5Hz AM modulated signal. For this test I connected the references of the generator and the spectrum analyzer (in to out) otherwise the frequencies would wander way too much.

Oh and let's see how busy the Wifi band is:

Advantest is also very candid about the expected life of various parts in their equipment:

I tried to find some information about the number of hours it has been on and the number of attenuator cycles it has been through but I have not been able to find that yet. There is a service menu and I expect to find the information there but this is protected by a password which -ofcourse- isn't in the manual.

When I have more time I'll open it up and take some pictures from the inside. I most definitely want a working backup image of the hard drive (according to the manual it is a flash drive) in case it fails or gets corrupted.
« Last Edit: July 12, 2016, 10:42:06 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline uncle_bob

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #1 on: July 13, 2016, 12:17:37 am »
Hi

If it's like it's HP Cousins, the calibration info is all stored in ... wait for it ... battery backed up RAM. The thing to watch out for is the life number on the lithium battery.

Bob
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #2 on: July 13, 2016, 12:22:49 am »
My current/previous two Advantest spectrum analysers both needed the backup batteries replaced but the self calibration (for which the calibration output is necessary) seemed to do just fine to get the calibration constants back to where they need to be. But still the battery and what it backs up is a concern to me on this one as well. I will investigate that as well.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline uncle_bob

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #3 on: July 13, 2016, 01:25:17 am »
My current/previous two Advantest spectrum analysers both needed the backup batteries replaced but the self calibration (for which the calibration output is necessary) seemed to do just fine to get the calibration constants back to where they need to be. But still the battery and what it backs up is a concern to me on this one as well. I will investigate that as well.

Hi

On some of the HP devices, once you loose the calibration information, there is no going back ....

Bob
 

Offline rf-loop

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #4 on: July 13, 2016, 05:31:41 am »

Time for some play. First a 3GHz carrier with a 5Hz AM modulated signal. For this test I connected the references of the generator and the spectrum analyzer (in to out) otherwise the frequencies would wander way too much.


Quite a spectacular at that price.



In my room ~1GHz AM5Hz50% looks like this with undefined Sig SA  and HP8644B.  (but my modulation is sine)
Swt <3s.  Gen and SA not synched to same f ref.
(borders can also see my gen terrible 50Hz sidebands)
Pity this gen can not go to 3G.
« Last Edit: July 13, 2016, 05:36:57 am by rf-loop »
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Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #5 on: July 13, 2016, 10:51:53 am »
@rf-loop: I just checked and it seems I have used a square wave and 50% AM modulation. The generator is an HP E4421B.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #6 on: July 13, 2016, 08:22:22 pm »
Time to take the cover off. After removing the rear legs and 2 screws the cover was easy to remove but I didn't like what I found:

Removing the cover doesn't make anything accessible! The aluminium box with the fan in the front seems to be the PC unit. Behind that is what I think is the power supply (see the earlier picture of the rear). The RF part is on the other side:

The RF section seems to consist of several units you might be able to remove IF you remember which plug goes where. Ofcourse there is some old school RF plumbing as well:


I have not tried to remove the PC unit or power supply. I think that takes removing the rear plate (and lots of screws!) of the unit after which the PC and the power supply can slide out. I fear there are also lots of wires connected to the rear plate so it is not an easy job. But maybe I need to bite the bullet some day. The PSU fan doesn't sound too good even though it is moving air.

Fortunately it turns out the flash drive is easely accessible by opening a latch.

The flash drive is a standard compact flash card so I took it out, made a dump from it using Linux' dd command and put the dump onto a different compact flash card I had leftover. Then I put the copy into the R3477 to see if it worked and... yes it did! So at least I have a working backup image of the hard drive!  ;D
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline AF6LJ

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #7 on: July 13, 2016, 08:33:31 pm »
Yum More Spectrum Analyzer Goodness.
Sue AF6LJ
Test Equipment Addict, And Proud Of It.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #8 on: July 26, 2016, 09:56:08 pm »
Unfortunately my 'new' spectrum analyser threw me a nasty curve ball. Every now and then it shut down after throwing a 'Warning fan 4 stopped'.  :'( Without a service or maintenance manual it is hard to tell which fan is which. However the backup of the hard drive I made earlier did allow me to do some digging into the software and I quickly found several texts in the software. It seems it also checks the power supply rails! Unfortunately no way to tell which fan is fan 4.

Time for some further investigation and more disassembling:

The module on the left is the PC module, the one on the right with the mains entry is the PSU.

The power supply and PC modules removed. The power supply is build around a standard power supply from Lambda.


The PC and power supply slots:

It is hard to see in the picture but there are some bodges on this board.

Inside the PC module:

There is a fan which draws air into the module but also a fan which forces air through a large heatsink. Under the heatsink there seems to be a standard embedded PC module which is mounted onto a carrier board. On the left it looks like there is room for a standard hard drive but the (2mm pitch) connector has 50 pins instead of 44. Do I spot another botch?
Someone must have had a very steady hand to solder a capacitor on a TSOP (0.65mm pitch) chip!


A close-up of the power supply's output section. It is pretty crammed!


Back to the problem at hand. I decided to replace the fans for the PC module and the PSU anyway. The cooler master (Sunon) fan seemed to run fine (although it makes a lot of noise). The big fan to cool the RF section also seemed fine and doesn't make much noise anyway. I tried to select fans with equal or better airflow / pressure ratings and lower noise levels. I would have liked to replace the (noisy) Cooler Master fan as well but it looks like I would need to remove the heatsink on the PC board and that probably would also disturb the heat conducting rubber.

The new PC module fan. Unfortunately I had to get creative with the wiring. I didn't choose a very high end fan for the PC module even though it is a Papst:


PSU fans (old and new). As a replacement I selected a fan with a slightly higher RPM and pressure rating because I already noticed the PSU gets quite warm (at 76% typical efficiency that is not a surprise!). The original fan seems to be no longer available anyway.


Instead of the original mounting clips I decided to use rubber vibration dampening fan mounts:


Time to put it back together... unfortunately the fan exchange made the problem worse! Now it always shuts down after a minute or so :palm: After checking the tacho signals (connected a 1k Ohm pull-up from the positive supply to the tacho output) from the fans in the PC module and the big fan in the rear the problem pointed towards the PSU. So I compared the tacho signals from the old and new PSU fan. It turned out the old fan from the PSU doesn't output a tacho signal at all but commutation noise seemed to indicate the tacho should be around 150Hz. The new fan however runs faster and outputs 163Hz. As a test I decided to defeat the PSU fan failure signal and BINGO! No more 'Warning fan 4 failed' messages. Time to open up the power supply and look for obvious problems. Even though the new fan had been running for a short while in the PSU the tacho signal still worked so at least the PSU hadn't killed the tacho output.

Oh crap... that is crowded!

But... actually it is constructed quite cleverly. The black block (with metal clip) in the middle is the transformer. The PCB in the top left is the switching/control board, the PCB in the bottom left is the mains filter and the PCBs on the right are the output modules. At the bottom right there is also a PSU status board with an isolated power supply to provide a floating status signal. From what I have seen it is possible the remove the mains filter (which can be pulled out). After that the switching / control board can be unscrewed and pulled out to the left (the transformer is connected to the switching/control board with a connector and stays inside the PSU). However I didn't go that far! I measured whether the PSU had a short between the fan power supply and the tacho signal but that wasn't the case (measured 1.8 kOhm). I also did some checks on the PSU status board but nothing stood out. My guess is that the PSU checks whether the fan speed is within a certain margin and throws an error if it isn't. After some throught I decided to leave the fan failure signal open (defeated) since the PSU also has an over temperature protection. 'Fixing' the PSU would be a major undertaking and if it does rely on the fan operating within a small RPM range I rather do without that because things like that cause more problems than they solve.

I did modify the PSU a little though. There is an aluminium frame around the PSU to make it fit and hold the various connectors. Along the side there is an open duct which could allow the PSU to suck air from the fan exhaust which would basically mean the PSU is trying to cool itself with hot air. I decided to close the duct so it can't suck in hot air from the rear. I also tied the wires coming from the PSU together to (hopefully) improve airflow.


After putting a couple of dozen screws back (fortunately there are only 2 different types) the R3477 worked as it should! It is still noisy though mostly due to the small Cooler Master fan in the PC module.
« Last Edit: July 26, 2016, 10:01:10 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline AF6LJ

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #9 on: July 27, 2016, 12:47:11 am »
Cool making progress.
Sue AF6LJ
Test Equipment Addict, And Proud Of It.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #10 on: August 15, 2016, 03:03:54 pm »
I'm trying to contort the R3477 into making dumps of the sampled IF data (no luck so far) but I did find something interesting with the debugger! The code to enter the service mode: 17320504
That at least allowed me to read the number of power on cycles (1060 ish) and the number of hours it was on (730). Ofcourse lots of menus to adjust stuff as well but I stayed away from those.
« Last Edit: August 15, 2016, 03:12:47 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Wuerstchenhund

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #11 on: August 16, 2016, 05:09:27 pm »
Just curious, where did you get these rubber mounts from?




I searched around but I only ever find the simpler ones which have one or maybe two stops.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #12 on: August 16, 2016, 06:37:27 pm »
Just curious, where did you get these rubber mounts from?

From Farnell (a pack of 50):
uk.farnell.com/duratool/dtrfmm-1/fan-mount-universal-4-5mm-pk50/dp/2472730
Unfortunately they seem to be out of stock at the moment.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Muxr

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #13 on: August 16, 2016, 06:55:13 pm »
Nice progress! I ordered a pack of those dtrfmm-1 from Amazon here in the US. I might be looking to replace some fans on my FSEA30 as well.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #14 on: August 17, 2016, 01:24:11 pm »
@Muxr: Your FSEA30 is a good catch as well!  :-+
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline cncjerry

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #15 on: August 17, 2016, 09:07:13 pm »
Hey nctnico, when are you going to post more pictures?  I'm thinking about one of the analyzers.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #16 on: August 17, 2016, 09:32:37 pm »
Hey nctnico, when are you going to post more pictures?  I'm thinking about one of the analyzers.
What kind of pictures would you like? I think I have shown more of the inside than I wanted to already  :P
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline cncjerry

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #17 on: August 18, 2016, 01:17:22 am »
I'm looking more for signal work, primarily how it does with low level signals. Also, a very low RBW (averaged) of the calibration signal with a span of 1.2Khz.  I would like to see how the line noise sidebands look.  One of the issues with my 8568B and 8566B is the noise sidebands are more prominent than I would like.  So with a -10dBm signal from the calibration port, you can see very small peaks at +/- 120hz.  The peaks on my 8568B are down about 100dBc and the 8566B are -92dBc.  The 8566B started out really bad (-72dBc) until I reworked the cable paths adding a steel plate between the cables and transformer inside the analyzer.  It was recently one of the longer threads on HP/Agilent group.  I would like to see how much better the Advantest does. withj internal line noise.

So any low level (or even high level) signals with a 10hz RBW and a span of 1.2K would be helpful.  On the 8568 and 8566 you have to VBW average to see the low level line noise peaks.

Thanks
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #18 on: August 18, 2016, 11:47:36 pm »
I tried to find those spikes (I'm in 50Hz country so I guess I would be looking at 100Hz sidebands) but I can't see them. First I tried the calibrator output but that seemed to have a lot of noise. Then I tried a -70dBm 100MHz sine wave (from an HP E4421B) so I only get the noise from the SA itself but still no spikes.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline rf-loop

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #19 on: August 19, 2016, 06:42:04 am »
I tried to find those spikes (I'm in 50Hz country so I guess I would be looking at 100Hz sidebands) but I can't see them. First I tried the calibrator output but that seemed to have a lot of noise. Then I tried a -70dBm 100MHz sine wave (from an HP E4421B) so I only get the noise from the SA itself but still no spikes.

Your marker is around -80dBc in first image  and in previous msg cncjerry talk aput -100dBc peaks. Your noise level is 20dB over this level where he look sideband peaks.  Next image your marker is around -60dBc  if 50Hz modulation sidebands are at this level it mean quite high 0.2% (am) modulation.  If you see there in this case 50Hz sidebands ...well...something is failed and need repair. :-DD
« Last Edit: August 19, 2016, 06:47:53 am by rf-loop »
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Offline cncjerry

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #20 on: August 19, 2016, 06:50:51 am »
Nctnico, no, that's really clean.  If you are in the UK at 50hz, I would think if they were there you would see them at +/- 100 or 150.  So your shielding and supply is pretty clean. 
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #21 on: August 19, 2016, 09:18:05 am »
I tried to find those spikes (I'm in 50Hz country so I guess I would be looking at 100Hz sidebands) but I can't see them. First I tried the calibrator output but that seemed to have a lot of noise. Then I tried a -70dBm 100MHz sine wave (from an HP E4421B) so I only get the noise from the SA itself but still no spikes.
Your marker is around -80dBc in first image  and in previous msg cncjerry talk aput -100dBc peaks. Your noise level is 20dB over this level where he look sideband peaks.  Next image your marker is around -60dBc  if 50Hz modulation sidebands are at this level it mean quite high 0.2% (am) modulation.
It seems to me the noise is coming from the signal sources I used so if there are 50Hz modulation sidebands they are masked by the noise from the signal sources. I think I need a cleaner signal source for this test to get a better signal to noise ratio.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Wuerstchenhund

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #22 on: August 19, 2016, 10:24:18 am »
It seems to me the noise is coming from the signal sources I used so if there are 50Hz modulation sidebands they are masked by the noise from the signal sources. I think I need a cleaner signal source for this test to get a better signal to noise ratio.

If you have access to a 10Mhz Reference source like a GPSDO or Rb source try this. They usually come with a lot less noise than the old HP ESG Series generators.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #23 on: August 19, 2016, 06:16:05 pm »
I did some further reading into phase noise and I found a document called 'Spectrum analyser basics' from Agilent. I'm by no means an expert when it comes to spectrum analysers but I like to learn more to have confidence in what I see on the screen. However my typical SA use does not involve anything which has to do with radio communication (so far).
Anyway I did some further testing and decided to see if I could make some meaningful measurement for the phase noise 10kHz from the carrier which seems to be the norm. The R3477's manual doesn't specify the phase noise (at least not directly in dBc). I used 50MHz @-10dBm from my E4421B (yellow) with the 10MHz references connected and the  R3477's internal calibrator output (blue):

I think it is needless to say the E4421B's output is noisy indeed but that may be caused by my self made output amplifier.

I did find some peaks in the blue trace and put some markers on them. However they don't quite match the mains frequency although you could argue there are some small peaks which could be mains frequency related:

« Last Edit: August 19, 2016, 06:22:46 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline cncjerry

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #24 on: August 19, 2016, 06:31:21 pm »
So is the blue trace the average?  The 52 offset could be line related.  The 74 could be a slight oscillation in the voltage regulator.  I've had a hell of a time removing those regulator sidebands with decoupling.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #25 on: August 19, 2016, 07:06:31 pm »
Both traces are averaged 10 times but the picture shows measurements from two different sources.
« Last Edit: August 19, 2016, 07:21:29 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline Wuerstchenhund

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #26 on: August 19, 2016, 08:51:38 pm »
The R3477's manual doesn't specify the phase noise (at least not directly in dBc).

Apparently it's -100 dBc/Hz (10kHz offset):
https://www.custom-cal.com/ModelInfo.aspx?kn=1157&m=ADVANTEST_R3477&srv=Calibration

Quote
I think it is needless to say the E4421B's output is noisy indeed but that may be caused by my self made output amplifier.

Why don't you just use your 10MHz reference as input signal? Rb references and a good OCXO has a much lower phase noise than a vector RF generator like the HP ESG.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #27 on: August 22, 2016, 09:14:01 am »
Hello ntcnico.
I grabbed one of these analyzers from ebay as well.
Working fine but I found out that the calibration above 3.5GHz is off.
I guess the cal for the YIG Filter is not good anymore. (Tested against a RS-signal generator)
I think one can calibrate this through the service menu. However I also don't have the password.
Did you have any success finding the password on the flash disc?

regards
gernot
« Last Edit: August 22, 2016, 09:22:49 am by dschiedsch »
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #28 on: August 22, 2016, 09:21:20 am »
I already posted it earlier:
The code to enter the service mode: 17320504
Use at your own risk though! I'd check if there isn't some frequency compensation enabled in one of the many menus.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #29 on: August 22, 2016, 09:24:52 am »
Hi
yeah thought about that and tried to put everything back to default

also do you know if the calibration is stored on the disk?
if yes then a backup of the disk should minimize the risk of bricking the device
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #30 on: August 22, 2016, 09:55:32 am »
I have found some files which seem to have calibration data in them in the C:\Advantest\R3477 directory on the disk.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #31 on: August 22, 2016, 10:14:50 am »
Did you ever check your analyzer in the range above 3.5GHz?
Is it accurate there?
I've made a table with my measurements and attached it.

Also coud you check the values of your YTF Tune adjustment in the service menu
because mine reads 0 for parameters 1 to 6 which I find odd

thanx
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #32 on: August 22, 2016, 11:33:56 am »
Can you post a picture of which settings you are referring to so I can make sure I'm looking at the same?

BTW I found something odd: the frequency calibration file on my R3477 goes to 15.4GHz and it is indeed possible to select frequencies up to 15.4GHz!
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #33 on: August 22, 2016, 11:41:05 am »
Hi
I used a R&S ZNB8 network analyzer as signal source and compared the measured signal between my R3477 and a R&S FSP analyzer
Settings were ref +10dbm attenuation 20db span 100MHz and RBW=VBW=1MHz
Signal was 0dbm.
I measured the peaks with a marker and put them in a table.

And as you can see from the measurements at around 6GHz there is quite a discrepency between the measurements.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #34 on: August 22, 2016, 11:49:26 am »
Oh sorry
i realised that you meant the YTF settings  :palm:
and i saw that you have to go to the band select menu to change between the ytf harmonic modes.
and only the base band has TC whereas the H1,H2and H4 have parameters 1 to 6
Also if you select H4 band the setting of the upper screen is centered at 15.2GHz.
So it seems tha calibration goes beyond what the analyzer is officially working
anyway here is the picture
« Last Edit: August 22, 2016, 11:56:54 am by dschiedsch »
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #35 on: August 22, 2016, 12:14:17 pm »
Mine also shows numbers in that menu. Unfortunately I don't have the means to test at over 3GHz. I do have an ADF4350 board somewhere but I doubt that will be any good to check a difference of a few dB over a (relatively) wide frequency span.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #36 on: August 22, 2016, 12:24:58 pm »
Yes you're probably right.
I'm only lucky that I can use some equipment at work which I know is calibrated well.
I only used the analyzer below 3gig for a few months and didn't see any issues. Only to find out it was off when I measured a 5.8ghz video transmitter.

So next thing would be to find a calibration manual. Because changing values in the service menu and looking what happens is probably too painfully slow :-)
Any ideas where I might get this?
 

Offline suj

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #37 on: August 26, 2016, 11:50:26 am »
Hi guys. For some time i have Advantest R3681 32 GHz Signal/Spectrum Analyzer with integrated 6 Ghz generator. I suppose that this is the common platform with R3477 (Windows XP Embedded, touch scren, similar performance). And finally, the password for the service menu is the same - thank you guys :-+. I don't have the calibration instructions, but the search base is expanding now. Each instruction  (R3477, R3671, R3681) will be useful - service menu looks identical.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #38 on: September 09, 2016, 10:28:30 am »
Hi
The a1freq.csv file (changed filetype to .txt for attachement) in the Advantest\R3477\Fact_cal folder seems to hold the calibration values over the whole band.
It gets loaded at boot (I moved it to a different folder and the analyzer throws an error) and I think this is where I want to change values so
the dB values in the high band are correct.
Now the question is which column is what
Obviously the first is frequency and I would guess the second is the harmonics mode (aka if it's in base band or using one of the YTF modes H1,H2,H4)
The values after that I guess are correction values in dB.
The question is now what the different columns are for
different RBW settings maybe?

If anybody can make a better educated guess then please enlighten me.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #39 on: September 09, 2016, 03:15:41 pm »
You could try and change a few values with extreme numbers (+6 or -6) and see what happens.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #40 on: September 12, 2016, 08:03:34 pm »
Today I got round to (somewhat) checking the response on my R3477 to see if it has the same inconsistancies as dschiedsch showed. I tried one of the cheap ADF4530 generators but it seems I have received a defective one. So I resurrected an ADF4351 frequeny generator / sweep board I made a couple of years ago. The ADF4351 can generate frequencies up to 4.4GHz and I think my R3477 behaves OK since it doesn't have the sharp step around 3.2GHz. The second graph shows the output from 10MHz to 15GHz in order to give an idea about the amount of harmonics the ADF4351 spits out.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #41 on: October 03, 2016, 01:55:21 pm »
Hi
I started working on the a1freq file and indeed it does what I thought it would.
Its a calibration file for the frequency band.
the format is as follows:

frequency, mode of YTF, 5x 0db attenuation correction, 5x 5db attenuation correction, ..., 5x 55dB att correction, 6x 60dB and up correction
its a total of 66 correction factors but only 13 are unique. there are 12 sets of 5 and one set of 6

so now since I know what the values are for I can try recalibrating with a known source. Luckily I know someone from university ...
 
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Offline videobruce

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #42 on: October 20, 2016, 03:51:53 am »
Three questions:
1. How heavy is this?
2. What is the power consumption (watts)??
3. If the unit is powered on, can you change the battery w/o loosing calibration??
 

Offline dschiedsch

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #43 on: October 20, 2016, 10:33:42 am »
Im Not at Home for the next four weeks. However
The calib Data is on a cf Card so there is No Problem with a battery.
On the question of how Heavy it is i would have to Check  but there is a datasheet online so please Look it up.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #44 on: October 20, 2016, 09:34:12 pm »
Three questions:
1. How heavy is this?
2. What is the power consumption (watts)??
3. If the unit is powered on, can you change the battery w/o loosing calibration??
You can find the weight and power consumption in the manual you can download from here: https://www.advantest.com/service-support/electronic-measuring-instruments/operating-manual-of-discontinued-products
The calibration is stored on the hard drive which is a standard compact flash card. I have made a (working) backup of the CF card in my R3477. It is a PC so changing the battery only affects the BIOS but the standard settings work just fine.
« Last Edit: October 20, 2016, 09:36:04 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #45 on: March 07, 2018, 10:38:35 pm »
Today my R3477 threw me a nasty surprise. I have not used it for a couple of months and it rewarded me with a 'self test failed' message. Great, just when I need it for some tests.

Checking the diagnostics info showed the digital IF board wasn't responding.  Great! :rant:
Time to pull the digital IF board out. Since the boards aren't labelled I just pulled the one furthest away and it turned out the be the right on. The plugs are numbered according to the position they are supposed to be plugged in. Number 4 goes into the 4th connector.

Now here is the board:

What the hell is wrong with it?
Let's apply the standard fault finding tactic: check the fuses!

Bingo! Fuse F271 which seems to be the 5V rail is blown. Now to find the problem. An easy way is to push some current (with the PSU set to a low voltage) into the board and use the thermal camera to find the hot spot.

Which is this capacitor on the board:

I desoldered a similar looking capacitor and measured it. It turns out the be 22uf. Since I don't have those at hand I placed 2x 10uf/50V which should do it and botch repair the fuse.



After checking the short on the 5V rail was gone I powered the R3477 on and.... yes it works! Pfew...  ^-^
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline AF6LJ

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #46 on: March 08, 2018, 02:59:09 am »
Nice catch.
Sue AF6LJ
Test Equipment Addict, And Proud Of It.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #47 on: March 10, 2018, 06:37:49 pm »
Indeed. It just goes to show that boards which look very complicated and unrepairable can in fact be fixed. Ofcourse the approach Dave uses in the 'Data IO' repair video (EEVblog #1061) to find a shorted component also works but the thermal camera is just quicker.

Meanwhile I got the right fuse, soldered it in and put everything back together.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline DaJMasta

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #48 on: March 20, 2018, 06:36:38 am »
Got one of these analyzers and have been working to quiet it down, but I had a look around at some things which may be useful to others:

The fan monitoring is done by an FPGA under the CPU fan blower which overhangs from the main computer module - but it seems to be tolerant down to pretty low tachometer signals.  I hooked up the signal gen to the two board's fan connectors and verified both to be happy down to at least 50Hz.  The CPU fan is a 5V job, and the default blower is stupid loud... but what baffles me is that the computer module is designed to be run fanless (I suspect with some ambient circulation), so why throw in such a loud blower if anything?

The clearance from the board to the top cover of the module is around 35mm, so it's not easy to get a regular fan to blow across the fins, so what I opted to do was to get a 12V rated 60x60x15mm fan and mount it on the opposite side of the fan module attached to the top plate (three new screw holes, but easy to do and plenty of clearance to keep the intake from being obstructed).  Since there's space for a small hard drive there, it's unpopulated with the CF card for the OS and is open space.  At 5V instead of 12, this blower is quite quiet, and still manages about 70Hz on the tachometer signal.

The PSU I'm running into the same problem for, as best I can tell, it's the primary source of noise now.  I tried swapping in a fan rated for 4500rpm and it still wasn't happy, and yeah there's no tachometer signal from the PSU, just the alarm signal, so you'd have to find a similar RPM fan or spoof it somehow.  I looked around for settings for what's required in terms of RPM in the software, but it's all done in the FPGA it seems like, and with a hex editor I can see a command prompt call following the fan stopped error message to allow a shutdown to be called by the program, but not the shutdown call itself.  And really, I don't want to stop the thing from monitoring the fans altogether, I'd like to know if one fails legitimately too.

Anyways, for some other notes about the instrument:

The basic CF card is 50x speed, moving to a 140x or so card was a notable load time improvement

The processor board is an SOM-4470F with a 700MHz Pentium 3 and 512MB of PC133 RAM installed (but only running a 100MHz FSB).  It's designed to run fanless, so should be just fine with the ventilation for the card, and it's an ETX form factor board, so there's some chance a different board could be used (though with the FPGA interface and the various outputs mapped to the bottom connectors, it could be difficult to find a match, I don't know the spec.)  As it's a soldered on chip and a maxed amount of RAM, there's no upgrades to be had here.

Fan 1 is the CPU heatsink fan
Fan 2 is the computer module ventilation fan
Fan 3 is the 120mm rear fan
Fan 4 is the PSU fan

It appears that Fan 3 does not send a tachometer signal back to the computer module, it could be monitored on the board it connects to and then sent back as an alarm signal like with the PSU.

PAX.exe is the main screen you see in the operating system and it handles all of the rebooting from the fan monitoring, so closing it prevents the reboots if you're tinkering with the fans.  I was unable to see exactly how the FPGA talks to the program, the device manager is not installed, but it seems to be a parallel interface from the routing on the board, and using a terminal to monitor COM1 yields no results.

Most of the directories are hidden if you access the CF module on a different computer (you just have to check view hidden files in explorer on the instrument itself), but the important ones are C:\Advantest\R3477 where factory calibration information is along with some other stuff and C:\Program Files\Advantest\R3477 is where the application itself is, as well as text error logs.  For me, there's one more, C:\FIDTSERV , because that seems to be where the touchscreen recalibration software is.


I've got a replacement screen and touchscreen coming for my unit, but otherwise it seems happy.  Had to replace the lithium battery on the CPU board for it to keep time, but it seems to be a real solid instrument and I'm looking forward to having it around.
 

Online nctnico

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Re: Advantest R3477 9kHz to 13GHz spectrum analyzer
« Reply #49 on: March 20, 2018, 08:56:59 am »
I replaced most of the fans in mine (same airflow/pressur rating) and used the rubber fan mounts (see earlier post). I did disable the fault signal from the PSU. I think the fan on the CPU is the loudest and I did not replace that one. However I think it might be possible to just remove it because the fan on the CPU cage is already providing airflow.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 


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