Products > Test Equipment
Agilent E8357A
Miek:
All of the values in the file are 8-byte little-endian floats. The value starting at 0x20 (let's call it x) seems to relate to the number of entries in the file. Then there are x/2 values denoting the frequency of each entry. After that, there are x*2 values which I'm guessing should be paired up into complex numbers and then matched with the frequency list.
Edit: also, the first value in the file is the total number of doubles in the file (not including itself), so (634+1)*8 = 5080 bytes and (459+1)*8 = 3680 bytes. The next value is 4 in all examples, and then the next two values are either 0,1 or 1,0 depending on the filename p21 or p12.
joeqsmith:
Attached showing both headers and data (after decimate) for Forzaman's files on log scale.
Yes the first index is the number of total records. Then the number of receivers (?). Receiver select, number of frequencies tested, table of the frequencies tested. Then the data, ping ponged between the two receivers. All is double.
We can see Forzaman's system is only 6GHz and will need to be aligned after they increase the range. Mine has data to 9GHz because I generated the files after I extended the range. Of course it's all garbage.
Now that all this makes sense, next step is to write some software to align it.
I am not sure why their files are missing data for the two receivers after I am guessing the range changes. I would expect they would have data for all four. Odd.
Forzaman:
--- Quote from: joeqsmith on November 08, 2022, 10:01:43 pm ---Attached showing both headers and data (after decimate) for Forzaman's files on log scale...
--- End quote ---
Great info. I should be able to get my hands on the required power meter and sensors to perform the receiver calibration once my unit is upgraded. The E4419B won't have the G12 or H12 option (higher accuracy certification), but will be calibrated, as will the sensors. I can send you the Cal files once this is done.
joeqsmith:
I have to purchase or rent equipment to align it. I did write a simple program to create the two files and set a unique value for each of the four columns. I used the receiver display to monitor the effects and map out the receivers while changing one column at a time. I can cause a shift across the entire range.
I wonder what they were trying to accomplish. I've been using mine without these files since it arrived and again, don't believe it ever had them from the factory. Any flatness would have been addressed when performing the calibration. This is where we need Joel Dunsmore to chime in. He may be able to provide some much needed insight.
When I look at your files, it seems unstable and not what I would expect. I could understand a shift as it goes through the bands but not like what you have going on with the higher frequencies. I wonder if you made some sort of flatness measurement and then tried to rename the files in the C:\programs...., exit and reload the PNA program (no need to reboot), how it effects the flatness. Maybe just use the receiver display with nothing attached to the PNA's connectors. It would also be very interesting to see your files after you align it.
Your files are basically +/-1. I use using 10, 20.. :-DD What's interesting is that this seems to cause other problems. Almost like these changes are not just a function of some software math but changing something in the hardware? Sorry I didn't take any photos, but instead of just seeing a shift, in one channel, it caused a different channel to become unstable (shifts of several 10s of dBs.). Really odd.
joeqsmith:
Under $100 and covers the entire range!
https://www.ebay.com/itm/284299377445?hash=item4231903b25:g:ztQAAOSwYipgpMWS
:-DD :-DD :-DD
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