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#50 Reply
Posted by
cncjerry
on 08 Jul, 2015 07:14
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I just posted a question asking how you get the r3131a apart. I took the back cover off and got stumped from there. I guess I should carefully change the battery under power as I have a tracking generator on mine.
Question is how do you get it open? I wanted to tweak the master oscillator unless it can be done in software? When measuring a 10Mhz signal the counter reads low by 182hz. Just enough to annoy me.
Thanks
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#51 Reply
Posted by
diarcy
on 13 Jul, 2015 14:56
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There's an way to adjust the master oscillator without taking the back cover off. There's a small hole on the back panel next to the external 10MHz input. Insert a small screwdriver to adjust the pot which controls the frequency. Hope this helps!
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#52 Reply
Posted by
cncjerry
on 14 Jul, 2015 21:50
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Wow, thanks, I remember seeing something next to the 10M input.
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#53 Reply
Posted by
flolic
on 15 Jul, 2015 07:44
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What kind of battery is in the unit, lithium? What replacement should I get?
I don't want to loose +43dBm input option on my unit.
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#54 Reply
Posted by
diarcy
on 15 Jul, 2015 21:18
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On my R3131A, the battery is a 1/2AA, 3.6V Lithium, Type ER3 from Maxwell. The date code on mine was 98-06 so it lasted 17 years! (Though, it was completely dead... 0.3 Volts.)
I could not find any ER3 types but I ended up using a Tadiran TL5902/PBP which is also a 1/2AA. Mouser has this battery for $5.95.
I'm not sure how one would replace the battery without loosing power to the RAM -- if that's where the option codes are stored. I'm sure there's a way to do this. Maybe if you can trace out the battery circuitry you can find a way to do this.
The battery is located on the CPU board which is the top-most board. It's easy to take the back cover off and then (gently) pull the board out. The floppy drive will come out as well.
I still have not found a way to re-enable the Tracking Generator... and I have not yet heard back from Advantest's Service Partner.
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#55 Reply
Posted by
diarcy
on 15 Jul, 2015 21:27
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cncjerry -- do you have a copy of the Maintenance Manual? This has the setup procedure for making the adjustment in Section 4.
The adjustment is to be made at 1GHz using the Frequency Counter on 1Hz resolution. In order to make the adjustment, one would need a 10MHz Frequency Standard which is fed into a RF Signal Generator that can output 1GHz at -10dBm.
On mine, after a good 30 minute warm-up, I was able to adjust the Master Oscillator to within 5 ppb or so. (That is 5Hz out of 1GHz.)
In general, the Maintenance Manual is not very good. There are no schematics.
I found a scanned PDF copy on the Internet.
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#56 Reply
Posted by
diarcy
on 15 Jul, 2015 21:33
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If you need the R3131 Maintenance Manual, I Google'd the following:
Advantest R3131 maintenance manual
The first link that popped up was "Manuals - KO4BB.com"
I have no idea who's site this is but the very first item is the R3131 Maintenance Manual. It's a PDF so it should be safe from any viruses.
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#57 Reply
Posted by
cncjerry
on 16 Jul, 2015 06:22
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I have a 10M standard but no 1Ghz generator. I'll have to figure out a way to do this correctly. Usually that's means buying something. I've used the TG from my 3131a pretty effectively. I have to tune some 1Ghz cavity filters I am making so maybe it is time for a new signal generator.
I am milling copper cavity filters for the Scotty spectrum analyzer. I thought I would build one as I like the idea of having a pretty complete instrument where I know all the software.
I've downloaded manuals from K0bb, very good site.
The battery has me buggged, I would hate to lose my TG in the advantest. Couldn't you solder a battery onto the existing traces then clip the old one out?
So how do I get the darn thing apart anyway? I'm not going to rush into it, but I could never figure it out, though I didn't spend much time with it. I took the back off, the front bezel, but stopped there when I saw all the sheet metal.
Thanks for the oscillator tips.
cncjerry -- do you have a copy of the Maintenance Manual? This has the setup procedure for making the adjustment in Section 4.
The adjustment is to be made at 1GHz using the Frequency Counter on 1Hz resolution. In order to make the adjustment, one would need a 10MHz Frequency Standard which is fed into a RF Signal Generator that can output 1GHz at -10dBm.
On mine, after a good 30 minute warm-up, I was able to adjust the Master Oscillator to within 5 ppb or so. (That is 5Hz out of 1GHz.)
In general, the Maintenance Manual is not very good. There are no schematics.
I found a scanned PDF copy on the Internet.
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#58 Reply
Posted by
corax
on 16 Jul, 2015 07:18
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The battery has me buggged, I would hate to lose my TG in the advantest. Couldn't you solder a battery onto the existing traces then clip the old one out?
Apparently the 3132/3162 did things differently with regard to the TG. I hadn't read about any of these problems and went ahead and replaced the same battery in my 3162 (old battery was completely dead). TG still worked afterwards (aside from a loss of PLL lock as it warms up; trying to fix that now).
I bet you could solder the new battery in before cutting the old one out. Or maybe use a temporary external current limited power source during the swap.
I wish that schematics/parts lists were available for these things. I've figured out a bunch of the circuitry in the r3162's TG, but there are some mystery parts in there.
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#59 Reply
Posted by
Fraser
on 16 Jul, 2015 11:17
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Standard operating procedure for replacing a Lithium cell whilst maintaining power to the SRAM...
1. Buy a 2 cell AA or AAA battery holder with flying lead output for connection to a PCB.
2. Fit 2 cells in the holder
3. Solder the flying leads to the supply rails that the Lithium battery maintains (observing polarity)
4. Cut the lithium battery off of the PCB
5. Desolder the lithium battery pins
6. Insert the new Lithium battery and solder its pins.
7. Desolder the battery holder flying leads.
8. Job done
Note this is all done with the power to the equipment
OFF !
For the very nervous amongst you, you can usually insert a 1K resistor in series with the battery holder flying leads, though this is not normally needed in the real world.
This approach came from an OEM service manual and is not some 'hack' method
Aurora
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#60 Reply
Posted by
cncjerry
on 27 Jul, 2015 18:44
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In the procedure above, why are two batteries used, to keep the dead battery from drawing it down? Is the 1k preferred?
Has anyone sent a 3131a to Advantest repair to have the battery replaced? If it was less than $300 I would pay it. I can't lose my tracking generator...
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#61 Reply
Posted by
Fraser
on 27 Jul, 2015 21:52
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2*1.56V = 3.12V
The minimum voltage threshold of some volatile memory is approx 2.5V.
1K resistor is not essential. Battery pack is connected to the volatile memory and the dead Lithium cell is isolated by the series diode between it and the memory supply rail.
Aurora
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#62 Reply
Posted by
nctnico
on 19 Oct, 2015 13:05
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Hello all,
After replacing the Lithium Battery on my R3131 (which lasted 18 years), the RTC is again working, but my Tracking Generator (Option 74) is no longer recognized. This seems to be a common problem when the battery is replaced but I have yet to see a solution.
Maybe there is. In my R3131 the battery went flat and after replacement it wouldn't start properly. However.. I found a switch on the CPU board and when I pressed that while my R3131 was powered on it came back to life. This button probably initiates some kind of RTC data init. I may revive the tracking generator as well.
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#63 Reply
Posted by
krivx
on 19 Oct, 2015 13:42
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#64 Reply
Posted by
Fraser
on 19 Oct, 2015 13:56
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Not an issue. The SA unit is not connected to the mains. The only power present is that from the batteries and the ESD status of the soldering Iron has no effect on such.
Fraser
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#65 Reply
Posted by
Marcel
on 20 Oct, 2015 14:25
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Regards,
Marcel
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#66 Reply
Posted by
marshallh
on 20 Oct, 2015 17:14
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Thanks Marcel, I inferred from your video that Total Gain cal failure was due to overall amplification drop occuring while heating, falling outside the range auto-cal could compensate for.
Your solution was to increase the gain of one MAX4106 opamp. Is this right?
I couldn't find the circuit in my pictures so I will check under the RF cans on the RF board.
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#67 Reply
Posted by
Marcel
on 21 Oct, 2015 15:07
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Marshallh
Your solution was to increase the gain of one MAX4106 opamp. Yes that is right.
This is not my video but You-Tube is my (best) friend.
Regards,
Marcel
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#68 Reply
Posted by
jc81382
on 31 Jan, 2016 19:14
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Hello,
I came across this post while searching for answers with my R3132 and I am hoping someone might be able to help me out.
Long story short I have a R3132 that I am trying to sell on eBay. It seemed to be 100% operational but I figured I would send it in for Calibration first as it would add a level confidence for the buyer and hopefully get me more money.
The unit ended up failing calibration and now I am trying to look into some common issues with the unit (that is how I ended up here).
After i saw some posts about the Self Test I decided to run it and I am getting 2 failures, CPU and RF.
I noticed that the date does not hold so I am assuming that the battery is dead and I wonder if that is causing the CPU failure. But I am not sure about the RF failure.
I don't know if it is helpful or not but i have attached a copy of the failed Calibration Certificate.
Thanks in advance.
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#69 Reply
Posted by
nctnico
on 31 Jan, 2016 19:19
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After I replaced the battery I had to run the self cal again to make accurate measurements so it is very likely the bad battery is causing your problems.
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#70 Reply
Posted by
jc81382
on 31 Jan, 2016 19:21
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Nctnico,
Thanks for the response, I will look through the manual to try to find the replacement battery #.
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#71 Reply
Posted by
jc81382
on 02 Feb, 2016 23:03
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**Update**
Sorry to hijack the thread again but there doesn't seem to be any for the 3132...
I went ahead and replaced the battery, now I get no errors on the initialization and the CPU Error, when I run the "Self Test" has gone away.
However I still have the RF Fail with the "Self Test" and when I try to run the "Self Cal" I get a 807 Error no calibration signal.
Any ideas?
Thanks
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#72 Reply
Posted by
nctnico
on 02 Feb, 2016 23:42
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Try and press the button on the CPU board while it is on like I described in a few posts earlier. I doubt it will work but if it does it is a simple fix. If not then you are looking at a repair.
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#73 Reply
Posted by
jc81382
on 03 Feb, 2016 00:41
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I don't think that switch is something I can get at while the unit is powered on.
Plus, after reading this thread over and over, as well as one on a Yahoo group I think it might have something to do with that strange sliding switch in some of the pictures. However, I'm not sure how to go about adjusting it.
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#74 Reply
Posted by
nctnico
on 03 Feb, 2016 09:17
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I don't think that switch is something I can get at while the unit is powered on.
The push button is near the rear so just leave the rear cover off and use a plastic pen or a thin finger.