Author Topic: Advantest R3131A Spectrum Analyzer 9KHz-3GHz  (Read 127604 times)

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Offline stellavox

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #275 on: June 28, 2019, 08:40:41 pm »
Hello,

I appreciate all the work you have done for the 3131. 

I just got one and replaced the battery per the info in this thread.  Working my way thru the pass/fail tests.

The TG in the unit doesn't work and the main connector wasn't plugged in.  anyone have any info on it and where to begin to service.

THANK YOU
 

Offline SaabFAN

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #276 on: June 28, 2019, 09:52:52 pm »
The TG can be enabled in the Service-Menu. If I remember correctly, it was SHIFT + 5 and the Password should be somewhere in this thread here if its not 232355.

Offline stellavox

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #277 on: June 29, 2019, 12:42:45 pm »
Thanks Saabfan,

The function IS enabled but I get an error message that the output is not levelized, and I believe there is no output at all.

Looking for some kind of block description on what goes on inside the TG module so I have a place to start troubleshooting.

Charles
 

Offline SaabFAN

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #278 on: June 29, 2019, 01:38:31 pm »
Try running the calibration-routines in the service menu. With the battery empty / replaced, you have probably lost most cal-data.

Offline IRB

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #279 on: July 12, 2019, 08:29:53 pm »
Thanks Saabfan,

The function IS enabled but I get an error message that the output is not levelized, and I believe there is no output at all.

Looking for some kind of block description on what goes on inside the TG module so I have a place to start troubleshooting.

Charles

If you have access to to another spectrum analyzer, connect the 3131 TG out to its input, I found the TG tuning was so far off even at full span the sweep was unable to see the TG output.   

You could try the SELF CAL press the "SHIFT" (Blue Button) then press the "CAL" or 7. Run the "Cal all" by pressing the soft key to its right.
 

 

Offline IRB

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #280 on: July 17, 2019, 03:17:06 pm »
Hello,

I appreciate all the work you have done for the 3131. 

I just got one and replaced the battery per the info in this thread.  Working my way thru the pass/fail tests.

The TG in the unit doesn't work and the main connector wasn't plugged in.  anyone have any info on it and where to begin to service.

THANK YOU

On the Tracking Generator module there is an SMA connector and a SMB connector, along with the ribbon cable. If thse ar not connected then the T.G. module will not work properly.

When I had the SMA cable disconnected I got a 802 TG un-level error.

In the picture below, there is a feed through in the lower left corner of the lower left compartment, this voltage should be close to 0V. It should be between +12V and -12V. It is the same point as the test point "Tune".     
 

Offline dc8wan

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #281 on: January 05, 2020, 11:24:53 pm »
Hello,

I search for the partnumber from the "PROBE POWER terminal". An the CPU
The Manufacturer is LEMO.
I don't find any information over this connector.

regards Marco
 

Offline dc8wan

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #282 on: January 06, 2020, 10:45:40 am »
Hi,

have found the partnumber from the connector.
FFA.0S.304.CLAC42

Source http://w140.com/tekwiki/wiki/LEMO_S-series_connector
 

Offline Lars2

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #283 on: September 23, 2020, 01:19:10 pm »
Hi,

I have some trouble with the TG of my 3131A. It seems to be the know problem with the 2nd LO frequency. My question: what is the frequency supposed to be? The information posted in this thread say it is 3840MHz but the frequency is always posted in conjunction with the 3132. I am asking because I measured the frequency using a near field probe and a scope and got a value close to 4.1GHz. Also the silk screen on this particular area also says "4.1G". Does that mean, that the 2nd LO in the 3131A is supposed to be 4.1GHz? or is my TG that far of?

Regards

Lars
 

Offline conmega

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #284 on: February 27, 2022, 03:11:05 pm »
Just remembered, I uploaded my 2nd LO adjustment guide to the Advantestinstrument Yahoo Group. You can download it from there. Its over 1MB so cannot be attached here.

https://groups.yahoo.com/neo/groups/advantestinstrument/files/-%3DAdvantest%20-%20R3132%3D-/

UPDATE & WARNING

Please read all of this thread. It has become apparent that two versions of R3132 RF module were made. My newer modules use a dropper resistor in series with the 2nd LO MMIC and buffer MMIC supply rails. Earlier versions of the RF Module do not contain this dropper resistor ad use a lower supply voltage to the MMIC's. This thread contains details of teh lower voltage level measured by a fellow forum member.

Fraser

Hey Fraser,

Would you happen to still have this doc now that Yahoo Groups is dead?
I got a pair of R3132s cheap at a swap meet locally. Looks exactly like the 2nd Stage VCO has drifted.
Been reading through the thread but haven't seen a secondary source for that alignment doc you made yet.

If you could make that available again I'd appreciate it!

Thanks,
-Connor K
 

Offline rainbow

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #285 on: March 16, 2022, 03:15:04 pm »
Would you happen to still have this doc now that Yahoo Groups is dead?

I got a pair of R3132s cheap at a swap meet locally. Looks exactly like the 2nd Stage VCO has drifted.

You can find it at https://groups.io/g/advantestinstrument/files/-=Advantest%20-%20R3132=- after group subscription.
Just as a metric (if you can say): how much have you paid the not working R3132?

I have an R3131 without TG and I would like to add it if I find one at reasonable price (working or broken) from a spare device. If someone has that feel free to contact me privately. Thank you.
 
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Offline [steven]

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #286 on: October 15, 2022, 02:24:03 pm »
Hello everybody,
I got an advantest r3131  a few weeks ago, I already replaced the battery and also replaced to floppy drive for a gotek flopppy emulator.
But I still have one problem with the tracking gen.
When enabling the tracking gen in the menu (which I unlocked using the pwd) I cant see the signal in the spectrum appearing.
I've already attached an RF transmitter transmitting at static carrier to the input of the analyzer, this works fine and is also at the expected frequency.
I've also attached the tracking gen to an oscilloscope and this shows the expected up chirp in the time domain.
So the RF output and input seem to be working but connecting both to each other doesn't.
However I do see the following in attachment 1.
Multiple peaks at a negative frequency? (which also confuses me, a negative frequency is only possible in mathematics right?)
When detaching the tracking gen I get what can be seen in attachment 2.
« Last Edit: October 15, 2022, 02:26:31 pm by [steven] »
 

Offline cncjerry

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #287 on: October 18, 2022, 04:48:31 am »
I'd have to look at mine, but you are centered on zero hz with any span you are potentially going to see the peaks below zero, but I agree, they shouldn't be there but you shouldn't be centered on 0hz either.

did you turn on the TG?  you have to run the cable from output to input and then turn it on in one of the settings.  If you have it enabled in the operator menus, have the hardware in your analyzer, enabled in firmware, and still don't see a trace, then the TG output it shot.  nothing unusual as many people hook outputs to outputs and blow one or both.  I don't remember if anyone ever found a service manual for a 3131?

one other thing to try, after you are sure you have the Tg turned on, use a scope to see if there is any RF coming out the Tg port.  It might not be sweeping.  Again, I cant remember, but when testing, keep the RBW and VBW on coupled (not manual) because some analyzers have limits in RBW when using a TG.

Jerry
 

Offline nctnico

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #288 on: October 18, 2022, 10:21:35 am »
In addition to the useful tips of cncjerry: One more thing to try is to hold the button on the mainboard during power up. I used to own an R3131 myself and after replacing the battery it wouldn't start. Holding the button on the mainboard during power up restored normal operation. I assume it does some parameter reset. Long shot but worth a try.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline [steven]

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #289 on: October 19, 2022, 08:10:50 pm »
Thanks for the replies. Checked it with an o'scope, turns out my TG has an offset by almost 22 MHz.
Probably the same issue that was reported by other people.
Already did the mainboard switch trick, didn't work unfortunately.
 

Offline dtxy101

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #290 on: December 02, 2022, 10:10:13 am »
At long last I had some time...

Thank you Fraser, thank you RadioAct, and all the contributors, for all the information, pictures, schematics, testing, data and instructions.

I went through almost all of it... Directly controlling the varactors proved I was on the right path, and the TG could be saved.

I do not have a good way to measure the 3840MHz, so I set the tracking generator to 500MHz -40dbm feed that in to a Rigol DSA815 with a 10MHz GPS reference.

I have what was called the "Type 1 early" Advantest tracking generator. But the ugly kind with no adjustment arm, just a 1206 0 Ohm resistor to move around... back and forth all around, it did not help, the VCO stayed at -11.21Vdc...

I built up solder, then I wicked away solder.

Finally I decided to stack a capacitor on top of C312 to simulate moving the dielectric trimmer.
See Fraser's pdf: https://www.eevblog.com/forum/testgear/advantest-r3131a-spectrum-analyzer-9khz-3ghz/msg864931/#msg864931

Measurement at TP401 "TUNE", with cover held on by gravity
-11.21V with 0.5pf -5.21V with 2.0pF -5.70V with 4.7pf -9.83V with 15pF, -10.18V with 22pf 0805 Package

I am staying with the 2.0pF, I don't know the original value of C312 but this gives it some swing the op-amp is running of +/-12V

For any one having low +12V, check the power supply fan, mine was pulling down the +12V supply.

While typing this the VCO has moved to -5.38V and holding the 500MHz it is set to.
After a Self Calibration the voltage is -5.51V~-5.52V.
Next is to put it all back together and see if it stays working.

Again thank you all for the information.



 :-+Is the test normal after TG repair?
 

Offline IRB

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #291 on: December 13, 2022, 05:37:13 pm »
Thanks for the replies. Checked it with an o'scope, turns out my TG has an offset by almost 22 MHz.
Probably the same issue that was reported by other people.
Already did the mainboard switch trick, didn't work unfortunately.

I see "dtxy101" re-posted my repair.
 

Offline [steven]

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #292 on: December 31, 2022, 09:24:41 pm »
First of all happy new year everyone.
Sorry for my late reply, I've a bit busy with some other things.

I've taken out the RF board from the SA and removed the shielding from the TG.
As far as I understand there are two versions of the TG, how do I recognize this and where would the adjustment arm be?
Also where is TP401 located?
« Last Edit: December 31, 2022, 09:26:29 pm by [steven] »
 

Offline IRB

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #293 on: January 11, 2023, 08:03:57 pm »
First of all happy new year everyone.
Sorry for my late reply, I've a bit busy with some other things.

I've taken out the RF board from the SA and removed the shielding from the TG.
As far as I understand there are two versions of the TG, how do I recognize this and where would the adjustment arm be?
Also where is TP401 located?

Steven, you have the "No arm" version, like I have. Look several post above this. I have two images, zoom in on the picture that is not the inside of the tuning section, there is silkscreen says "TUNE" in white lettering, that is TP401 also "P2"

It's been a while, so I'm not sure it might also be the blue wire "VTUNE" <- you will need to check this!

I suggest you get some low value SMT Caps, and try soldering them in parallel with C313(My board did not have a designation for the cap)
 
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Offline [steven]

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #294 on: January 12, 2023, 10:27:39 pm »
Thx for your reply. I've measured VTUNE which is at -11.19V, very similar to your TP401 voltage. As a first try I completely removed my tuning resistor. And my TG works now! VTUNE settles around -6.30V after a while and my TG output frequency also seems to be spot on.
Thanks for the help!
 

Offline pmax65

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #295 on: January 22, 2023, 05:15:36 pm »
Hi there,
since I repaired my very early R3131, but the reference signals are almost the same for the later R3131A version, I believe that somebody could be interested to the pdf files I did for the RF board and the RF sampler boxed block.
These files are the images of the RF board with superimposed the nominal signals values for almost all the significant points of the RF board functions itself.

At the bottom right of the picture into the RFsampler_measurements.pdf file, you can find the values for the 4th IF variable amplifier that is the "thorn in the side" of the instrument along its ageing.
Those value are the original ones for the very early Japanese instruments (the R3131 not A), but following Analog Devices datasheets they are better than the values used later in R3131A version. It seems that Advantest engineers didn't a good job designing that amplifier, and they did worse trying to do it better indeed.

The values shown below "Modded version for extended gain" are those I changed to those of the final production values (the "R3131A" version) to extend and center the gain and definitively fix the issue.
For that components setup I got a 9dB to 26.6dB range for the whole 12 bits DAC output codes (from 0000h to 0FFFh), with the middle gain of 20.8dB @ [RF] > [IF Amp] > [OFS ADJ] = 0800h

I hope you get aid from these files and you could fix you R3131 easily.

Massimo

 

Offline flolic

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #296 on: February 23, 2023, 01:14:43 pm »
After resetting to defaults (Shift + Config keys), my R3131 is showing level in dBμV instead of dBm. That started after replacing bad internal Lithium battery.
I can change units back to dBm in Level menu, but it will revert back to dBμV after every reset.
Is there a way to change default configuration?
 

Offline rainbow

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #297 on: March 08, 2023, 01:15:28 pm »
I can change units back to dBm in Level menu, but it will revert back to dBμV after every reset.

Have you reset the config using the device button in the motherboard during power on?
 

Offline flolic

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #298 on: March 08, 2023, 08:25:08 pm »
I honestly don't remember, I replaced battery few years ago.
Do you think that resetting the device via the button can fix the problem?
 

Offline rainbow

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Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Reply #299 on: March 08, 2023, 08:49:38 pm »
I don't know ;-) If you have already checked the manual I don't know others ways to reset the configuration.
 


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