Advantest R3131A Spectrum Analyzer 9KHz-3GHz

[konisan]

I lost my factory default. Could you write me some values? Shift+5 , pass: 882323 , I RF, YTO Tune, Max1stLO and Min1stLO  hexadecimal values. Thanks your helps.

Max1stLO 0x0DA6
Min1stLO  0x0120

I have a R3131, not R3131A.  I have rewrited above Max1stLO and Min1stLO value in my R3131 mistakenly.
Then the self test starts a error at lock detect.
Is there anyone who knows the original value of Max1stLO and Min1stLO for R3131, not R3131A.
How to get the values are the same as above.

Best regards,

[Marcel G]

Advantest R3131    serial number: 81780209

Max1stL0:  0X0CC8
Min1stLO:  0X0087

Regards,

Marcel

[konisan]

Hello Marcal,

Thank you very much for quick answer to my question.
Though I have used your values, the self test failed unfortunately.
My S/N of R3131 is 81780912.

Again thank you for your information.

konisan

[SaabFAN]

After a lot of reading on the internet and informing, I managed to replace a damaged 1st mixer of a Advantest R3131.
The original mixer (DMJ 4317-1) is no longer available but has found an excellent alternative by using an HSMS-2822.

Below you see two photos, one with the damaged mixer and a picture with the alternative mixer. Both photos were taken without any RF input. The differences are clearly perceptible.

Probably these diodes can also be used in other older Advantest Spectrum Analyzers, take advantage of them.

In any case, there is exactly the same mixer in the U4342 that I also have.

Small problem with that solution though: The HSMS-2822 is listed as "Last time buy" on Digikey and was declared obsolete by Broadcom in December 2017.
Unfortunately, there's no direct replacement available. Among the diode-pairs with a similar capacitance, the BAT68-04 is the one with the highest reverse voltage (8V instead of 15V).
Schottky-Diodes with reverse voltage higher than 8V all have higher capacitance - usually twice as high as the HSMS-2822.

No idea what that change in capacitance will do to the performance of the mixer, but my guess is that it's not an improvement

Hello Marcal,

Thank you very much for quick answer to my question.
Though I have used your values, the self test failed unfortunately.
My S/N of R3131 is 81780912.

Again thank you for your information.

konisan

Most likely, this is a value that needs to be individually set for each YTO. I have a R3131A and the Max1stLO-Value is 0x0DB3, the Min1stLO is 0x00D7. In your case, you probably have to try out a lot of values until you find the right one and the YTO-PLL locks again.

[konisan]

Thank you very much, SaabFAN
Solved!
I remembered that Min1stLO was around 0x0120. So, set Min1stLO:0x0120, then increase Max1stL0 until Lock Detect Pass.
The pass value was 0x0FA0, however it was critical. Sometimes fail, sometimes pass.
Then eventually , I set

Max1stL0:  0X0FB0
Min1stLO:  0X012D  (selftest lock detect pass, several times)

Note) I'm sorry I made a mistake of name of Marcel.

Then another problem :
I have replaced a battery on CPU board, and shiht +9, reload Tracking Generator. It was successful. However,  when TG on, "Error 802:TG Un leveled" message is appeared.  Is there any way to correct it ?

Thank you again.

[IRB]

When I had the "Error 802:TG Un leveled" message it was because of the bad backup battery. As you just replaced yours, check that your Center frequency is not 0 and the span is not going below 0Hz.
Try 5MHz, Zero Span, or try the Auto button.

I miss my 3131A. If any one has a good TG module schematic I am interested, or troubleshooting guild.

[konisan]

Thank you for the information, IRB-san.

I was tried and failed.
My center frequency can be set at any frequency including 0Hz and the span can go below 0Hz.  And tried 5MHz and 0Hz span, and push Auto Tune button. But Error 802 is the same.

Will you inform me of your step for TG recovery after the battery change?

Thank you again.      Konisan

[IRB]

I did not have the issue after the battery was replaced.
I had to cycle power after setting the frequency and span to trigger a save.
I fortunately did not loose the TG function from the memory.

Have you tried the the built in cal (SHIFT then 7) then run all the self cal. Sorry I can be more specific my 3131 is in pieces till I can fix or replace the TG module.

[konisan]

I have tried Shift+7 and run all the self CAL. But TG on, failed, Error 802 is the same.

IRB, Thank you again.

[IRB]

OK, I have replaced the power supply fan, it was pulling down the 12V.
I made extensions for the control cables, for the SMB to SMB  and for the copper hard line SMA to SMA.

konisan, to your issue, if I disconnect the copper hard line SMA to SMA, I get the 802 TG un-level error.

I hope this points you in a good direction.

[IRB]

Does anyone have more pictures of the inside of the TG module form a R3131A?
Or schematic or instructions, beyond the TG AUTO or manual adjustments.

My TG seems to be almost 3.5MHz on the high side, as measured on a 10MHz GPS locked Rigol DSA815, and I need a way to adjust it.

On the R3131A I have verified my internal 10MHz, with a 10MHz GPS locked reference from Jackson LABs. I connected it to the input and set the analyzer to 1GHz turned on the counter, I adjusted the internal reference until I got 1.000 000 012 GHz using the 1GHz(-89db) harmonic form the 10MHz reference.
Cold cycled the 1GHz came back 1.000 000 034 GHz

[IRB]

Further testing has lead me to believe there is a pair of varactor diodes, and one maybe bad.
The TUNE voltage from an upper board form a LM833 op-amp powered from +/-12Volts is pushing to -11.24V when I bridge pins 6,7 of the op-amp the voltage went to +10V and the RF frequency went higher. From this I would say the op-amp is working, but something else will not allow the frequency to come into range.

I don't know exactly what these two components are, I believe they are varactors, they are the marked  6.0 on the top edge and L6 on the body. I think there are SOD323?

If anybody knows the component, Please post it or PM me.
   

[SaabFAN]

A quick google-search brought up 6.0 Volt Zener-Diodes (Searched for "SMD Code 6.0 SOD323").

Btw. I think, you should open a Thread in the Repair-Subforum. You'll get help there much more quickly and more reliably. Here the thread is too quickly pushed down by general talk about T&M-Equipment.
Also a good opportunity to summarize what you've done so far and what you found out.

[IRB]

I'm leaning towards this Discontinued Panasonic MA368.
      http://pdf.datasheetcatalog.com/datasheet/panasonic/SKD00037BED.pdf

I e-mailed Advantest.co two days ago nothing back yet.


Might cross to SMV1408-040LF but wrong footprint(SOT23 or SOD-882)

I also noticed, as I moved my finger around the tuning cavity, it triggered 802 ERROR

[konisan]

IRB
Thank you for the TG information. After my last posting, I found the repair company (www.three-re.co.jp/) for R3131 in Japan, because Advantest is almost no business for spectrum analyzers today. And three-re company has a license to repair for Advantest. So, I asked for the repair of my R3131 TG. Then the answer was that they could not accept to repair because I had replaced the battery inside.
They said if the casing is open, they will not accept for the repairing. I have tried another repair company, but they have no technical skills to repair R3131. Eventually I have purchased the "Rohde & Schwarz SMY01" sweep generator at auction in Japan for US$300. It works very fine as TG so far.
Best regards,

[konisan]

Hello!

I have purchased a used R3131A through Yahoo auction recently for US$90. It works so-so, but IF STEP AMP test is fail in the self test.
In diag mode (shift+5), actually IF ATT test is fail.
Is there anyone who knows to correct it, such as an adjustment of some pot in IF board etc. ?

Thank you in advance.

Konisan

[nctnico]

There are some repair instructions floating around. IIRC this problem has something to do with analog switches and ADCs or DACs on the IF board. Under no circumstances you should try to 'adjust' the spectrum analyser unless you know what you are doing.

[konisan]

nctnico-san

Thank you for your comments. I'm going to find which pot on the IF board should be adjusted. After one hour power on, sometimes IF AMP test is 'pass'. So I think there is a very critical error.

[SaabFAN]

In my case, I had to change the value of resistor R120 to fix that exact problem.
Normal value is 390 Ohms, I placed a 470 Ohms resistor and now it is working again.
If I remember correctly, there are almost no pots in this instrument. All the adjustments are being done with DACs via the "Shift + 9"-Menu. The device will ask for a password, which you can find somewhere in this Forum-Thread.

[konisan]

SaabFAN-san
Thank you for the information to correct my problem. I hesitate a little bit to open RF input block. Because I think it is a little cumbersome for me and I am afraid whether it could be restored well. Therefore for the time being, I will use the R3131A under the current condition. Today I'm working to remove yellow rust color from the front panel.   

[Rémi]

Hi guys,

I'm currently trying to implement a python script to capture the screen of an Advantest R3131A via GPBI. My idea is to retrieve a sweep from the instrument. You can find the GPIB commands in the manual of the instrument : http://www.dudleylab.com/R3131-Manual.pdf (starting from page 201). I'm using the pyvisa library to retrieve the data. Here is my python code :

Code: [Select]

import visa

rm = visa.ResourceManager()
print(rm.list_resources())
SA = rm.open_resource('GPIB0::8::INSTR')
print(SA.query("*IDN?"))
print('Start frequency = ' + SA.query("FA?"))
print('Stop frequency = ' + SA.query("FB?"))
SA.query("CONTS")  # set sweep mode to normal and full
print('Sweep mode = ' + SA.query("SWM?"))

SA.query("TS")  # reset and take sweep
SA.query("TM FREE")  # set trigger to free run mode
print('What updates memory A at each sweep (0=write, 1=view, 2=blank) ? ' + SA.query('TA?'))
SA.query('AV')  # Send A view command
# query to retrieve sweep
test = SA.query_binary_values('TBA?', datatype='H', is_big_endian=True, container=list, header_fmt='empty', expect_termination=True)

print(len(test))
print(test)

rm.close

And this is what I get in the console :

Code: [Select]

('ASRL1::INSTR', 'ASRL3::INSTR', 'GPIB0::3::INSTR', 'GPIB0::8::INSTR')
ADVANTEST,R3131A,01780698,C00
Start frequency = +9.00000000000E+03
Stop frequency = +5.00000000000E+07
Sweep mode = 0
What updates memory A at each sweep (0=write, 1=view, 2=blank) ? 1
501
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

I only receive 0 data, but the length of 501 is correct, does anyone have a hint ?

Thanks!

[cncjerry]

I've received data from an R3131a so I know it works.  For some reason though, I thought I used ascii data.  If anything is wrong it would be in the data conversion of the received bytes.

I'll look around for my code, though it was in visual basic, it should still apply.

Jerry

[Rob_Gr]

Hi  fellow Advantest3131A owners
I have an Avantest R3131A without a TG.

It worked ok. But then It quit working. The SA froze and did not respond to keyboard input.
After switching off and on it worked again. A week later at startup it gave an “RTC data error” at the selftest.
The CPU battery was dead, so I replaced it with two penlite batteries.
Now the SA passes its selftest and then displays UNCAL. It does not respond to any keyboard input.
I tried pressing the button on the CPU board. After pressing the SA restarts, goes thru its selftest again and again displays UNCAL.
Any help in solving this would be much appreciated.

Rob

[nctnico]

Did you press the button on the mainboard while switching it on? Does it respond to the keyboard again?
The uncal probably goes away after doing a self calibration. This is simple: connect the cal output to the RF input and let the SA run the self calibration.

[IRB]

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.