FieldFox Frankencalibration

[jjoonathan]

Hey so I recently fixed up a FieldFox, but that's a story for another post. I need to give it a new network analysis calibration. The factory calibration ("CalReady") is pretty aggressive; even if you set a custom preset with your own calibration active the instrument will boot up with every aspect of your custom preset preserved except for the network analyzer calibration, which will be set back to CalReady. It bugs me to have a crummy auto-set, so I have to figure this out. It looks like the factory calibration is stored in:

Code: [Select]

C:\Flash\FieldFox\FactoryData\NAFactoryCalset.bin
I poked around and it looks like you can generate something in a very similar format by performing a calibration, saving the instrument state to a ".sta" file, unzipping the .sta file, and extracting "CalsetLibrary". Similar, but not exact. The header and footer are different, but if you graft them from NAFactoryCalset.bin to CalsetLibrary to form FrankenCalibration.bin and then replace NAFactoryCalset.bin with FrankenCalibration.bin it seems to work. The header differences are pretty trivial (different magic number and a constant that probably flags it as factory special, or records how much love it was made with, or something) but the footer has some stuff in there. Does anyone have any idea what the stuff in the footer is? Whatever it is, it's needed, and without it the parser runs off the end of the file. As far as I can tell the FrankenCalibration is alive and well, I'd just like to know what I grafted onto it to get it that way, lol.

[ATK]

Sort of a long-shot (and sorry for the thread necromancy), but has anyone figured out a way to back up calibration for a CPU1 Fieldfox? CPU2 allows you to take a full backup (which unless I'm misunderstanding, is what you were utilizing to apply your calibration here), but CPU1 does not allow you to access or back up the factory partition of the SOM module's flash. I'm mostly curious since that is the only thing which cannot be restored using Keysight's SD card recovery tool, and being able to restore cal on a bricked unit would be ideal.

[khanda]

Hey so I recently fixed up a FieldFox, but that's a story for another post. I need to give it a new network analysis calibration. The factory calibration ("CalReady") is pretty aggressive; even if you set a custom preset with your own calibration active the instrument will boot up with every aspect of your custom preset preserved except for the network analyzer calibration, which will be set back to CalReady. It bugs me to have a crummy auto-set, so I have to figure this out. It looks like the factory calibration is stored in:

Code: [Select]

C:\Flash\FieldFox\FactoryData\NAFactoryCalset.bin
I poked around and it looks like you can generate something in a very similar format by performing a calibration, saving the instrument state to a ".sta" file, unzipping the .sta file, and extracting "CalsetLibrary". Similar, but not exact. The header and footer are different, but if you graft them from NAFactoryCalset.bin to CalsetLibrary to form FrankenCalibration.bin and then replace NAFactoryCalset.bin with FrankenCalibration.bin it seems to work. The header differences are pretty trivial (different magic number and a constant that probably flags it as factory special, or records how much love it was made with, or something) but the footer has some stuff in there. Does anyone have any idea what the stuff in the footer is? Whatever it is, it's needed, and without it the parser runs off the end of the file. As far as I can tell the FrankenCalibration is alive and well, I'd just like to know what I grafted onto it to get it that way, lol.

Hi，Can you tell me what's model need factory calibration in your fieldFox？Maybe I can help you do it. And I Can add options also.

[jjoonathan]

N9952A -- yes, I would like any information you have on the factory calibration procedure! Thanks!

CPU2 allows you to take a full backup (which unless I'm misunderstanding, is what you were utilizing to apply your calibration here)

No, during the boot process it briefly shares the root filesystem. Late in the boot process it resets the share to point at user jail. You just have to be fast to escape user jail 

[khanda]

N9952A -- yes, I would like any information you have on the factory calibration procedure! Thanks!

CPU2 allows you to take a full backup (which unless I'm misunderstanding, is what you were utilizing to apply your calibration here)

No, during the boot process it briefly shares the root filesystem. Late in the boot process it resets the share to point at user jail. You just have to be fast to escape user jail 

The official has a calibration system called N7800A, but if you're using the N9952A, you need a top-of-the-line network analyzer, and you just can't afford that cost,.Could you please tell me which mode the indicators are out of tolerance(Lokke like VMA)? Is the trial network analysis mode functioning properly?

[jjoonathan]

Nothing is out of tolerance. The FrankenCalibration worked, or at least it is equivalent to manually enabling the VNA calibration obtained from my 85058B calibration kit, except that it happens automatically on startup.

Thanks for the info about N7800A though, I thought it must be proprietary but it sounds like the software exists outside Keysight and might fall into hobbyist hands one day.    Until then, we can copy and paste chunks of binary files in a hex editor lol.

[khanda]

Nothing is out of tolerance. The FrankenCalibration worked, or at least it is equivalent to manually enabling the VNA calibration obtained from my 85058B calibration kit, except that it happens automatically on startup.

Thanks for the info about N7800A though, I thought it must be proprietary but it sounds like the software exists outside Keysight and might fall into hobbyist hands one day.    Until then, we can copy and paste chunks of binary files in a hex editor lol.

You're welcome .haha,About N7800A you are right.Can you tell me about "FrankenCalibration"? Sry for my english.

[jjoonathan]

FrankenCalibration is the procedure in the first post, where I took pieces of a fresh calibration (CalsetLibrary) and pieces from the old built-in calibration (NAFactoryCalset.bin) and put them together to make a new built-in calibration NAFactoryCalset.bin .

Your English is good but perhaps the name "FrankenCalibration" is not clear without the cultural context. "Franken" refers to the story "Frankenstein" in which a monster is assembled by sewing together pieces of dead bodies and zapping them with electricity -- the assembly process is not fully understood and has undesired consequences. I meant this as an analogy to the assembly process of NAFactoryCalset.bin, which I did not fully understand but it still seems to work and my FieldFox has not come to life or attempted revenge after two years so I think I can declare it a success.

[khanda]

FrankenCalibration is the procedure in the first post, where I took pieces of a fresh calibration (CalsetLibrary) and pieces from the old built-in calibration (NAFactoryCalset.bin) and put them together to make a new built-in calibration NAFactoryCalset.bin .

Your English is good but perhaps the name "FrankenCalibration" is not clear without the cultural context. "Franken" refers to the story "Frankenstein" in which a monster is assembled by sewing together pieces of dead bodies and zapping them with electricity -- the assembly process is not fully understood and has undesired consequences. I meant this as an analogy to the assembly process of NAFactoryCalset.bin, which I did not fully understand but it still seems to work and my FieldFox has not come to life or attempted revenge after two years so I think I can declare it a success.

Thanks  for your patience.You are too smart!Would you mind giving me your FrankensteCalibration and original NAFactoryCalset.bin?I am very interested in it.And I like Franken movies

[jjoonathan]

Sure! See FieldFox_cal.zip, attached.

NAFactoryCalset_original.bin: the default calibration that came with the FieldFox

CalsetLibrary_new: new calibration from 85056D mechanical standards

NAFactoryCalset_frankenstein.bin: updated default calibration

I put the calibration which uses the 85056D mechanical standards into the zip file instead of the 85058B version because the 85056D calibration was collected entirely through the FieldFox and does not require understanding jupyter notebooks. In the unlikely case that you care about the difference, I put detailed measurements here:

https://github.com/jjoonathan/cal-std-8510-fieldfox

[khanda]

Sure! See FieldFox_cal.zip, attached.

NAFactoryCalset_original.bin: the default calibration that came with the FieldFox

CalsetLibrary_new: new calibration from 85056D mechanical standards

NAFactoryCalset_frankenstein.bin: updated default calibration

I put the calibration which uses the 85056D mechanical standards into the zip file instead of the 85058B version because the 85056D calibration was collected entirely through the FieldFox and does not require understanding jupyter notebooks. In the unlikely case that you care about the difference, I put detailed measurements here:

https://github.com/jjoonathan/cal-std-8510-fieldfox

Thank you very much. May I ask if you also work in instrument restoration? At least, that's what I do. I have a lot of service software here—would you be willing to PM me your email? It seems a bit disrespectful to discuss these things here.