Hi Andrew,

Thanks for your post above, and I apologize for the change in login name — I forgot my password. I’m going to walk through what I understand so far, and hopefully you can help me pick up the pieces after that.

In the case above with decimation of 32, this implies a sample rate of 40 MS/sec / 32 = 1.25MS/sec as shown on the GUI, and therefore the bandwidth of the spectrum shown is 1.25 MHz. You’ve applied a filter and Blackman windowed the data, which results in the rolloff we see in the spectrum window.

So: decimation controls the sampling rate, and the “IF Bandwidth” control in zero span mode controls the filter cutoff points, if I’m understanding things correctly. Question 1: Is this same filtering applied to the raw I and Q data recorded in the .iq files?

In the case above, we’ve chosen IF bandwidth of 1 MHz, so this is controlling the 6 dB down points of said filter… if we are only controlling the 6 dB down points, the effective noise bandwidth (ENBW) of this filter must be somewhat greater than 1 MHz, correct? Question 2: how much greater, and how can I determine/estimate the filter ENBW based on the description of the windowed filter you’re using?

I’ve looked a lot of places trying to find the ENBW for the combination of window and filter you’re using, but typically I find references to the resolution bandwidth of spectrum analyzers and so on, and I’m not sure these are really applicable to the ENBW for an IQ recording. An example is this page.

We’re using a calibrated noise source to assess our system gain and noise figure, but until we have a handle on ENBW for the BB60C, we’re floundering a bit. Any help/discussion would be appreciated.

Hi A.J. and Justin,

Sorry I did not answer your question re: processor. Yes, I am trying to get this to work with the 454 MHz ARM Freescale i.MX286. I’d be willing to switch though if you have an industrially-rated, low power device that you can recommend. I’ve looked at the Blue Steel (can’t seem to buy one though…) and the various ‘bones at Special Computing. Do you think the industrially-rated Mentorel machines might work? https://specialcomp.com/beagleboard/bone.htm

Thanks for the link to the ARM build. I have downloaded and unpacked it and now am trying to compile a simple test code. The code and my attempt to compile it are attached. Basically, it looks like some kind of issue with the FTDI driver. I am using the latest driver version from the FTDI website, and did not have any issues with it on the 32-bit build.

Thanks for your time,
DAN

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Gentlemen,

Thanks for your replies. I have tried the 64 and 32 bit x86 libraries, I am not sure that I have tried the ARM version associated with the Beagleboard.

I had no illusions about the sweep speed; that is not particularly important for my application. However, the ability to handle -40C (option 1), low power consumption and useful frequency range of the SA44 made it ideal for my project.

I’ll try to get a hold of the ARM library and give that a go, though I don’t see it listed on the SA44 download page anywhere…

Thanks,
DAN

[dbreton]

Hi A.J. et al,

I am also trying to get the Signal Hound to work with embedded linux, specifically the TS-7670. I’ll simply be logging the output to files, no GUIs involved.

I am having a similar problem with the libSHLAPI.a file, though my machine/compiler complains:

g++ CUSBSA.cpp -o USBSA.o
g++ main.cpp CUSBSA.o libSHLAPI.a /usr/local/lib/libftd2xx.a -o test_shapi -lpthread -ldl -lrt

libSHLAPI.a: could not read symbols: File format not recognized
collect2: ld returned 1 exit status

Is there any way I could get the source files that go into the .a library? I’d like to try to compile them on my machine to see if there is some weird architecture thing that is keeping this from working. Failing that (e.g. those libraries are proprietary or something) can I send you information about my processor and toolchain for cross-compiling?

Thanks in advance,
DAN

• This reply was modified 10 years, 1 month ago by dbreton.

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