[amsat-bb] Fox in a Box Question

[Burns Fisher]

Doug,

We'll have to wait for Chris to answer the question about compensating for
the I/Q offset (which is what gives the peak in the middle).  I have not
had that trouble at all, so I assumed he did it automatically like SDR#
does.  I use (and the FIAB should have the same offset if you downloaded
the image) 145930 as the center frequency.  That makes all the Foxes appear
on one side or the other.  I have found birdies in the spectrum, which I
think comes from ethernet switches around my house.  Some are pretty close
to Fox frequencies.  To work around that, I go to the Spacecraft menu and
chose the particular s/c that is too close to the noise and adjust the
lower and upper search bounds a bit to exclude the noise.  I think at worst
I made high maybe 3 or 4KHz above the center, and I had no trouble at AOS.

I assume that you do have "track" enable so that it is only looking within
those bounds for a signal?

BTW, do you have a FunCube Dongle Pro Plus (it has a + in the center of the
O in the logo)?  Chris has not had a FCD Pro (not plus) to fiddle with so
it may have a worse problem.

On Tue, Dec 11, 2018 at 4:08 PM Doug Phelps via AMSAT-BB <amsat-bb at amsat.org>
wrote:

> I had no problem replicating the Fox in a Box.  My 3B+ runs around 70% CPU
> when decoding white noise.  I am having trouble receiving the satellites
> because of the Spike in the center of the passband as well as images to the
> side.  Is there anyway to compensate for the offset voltage in LINUX that
> will run on the P! 3B+?  Programs like HDSDR allow you to do the correction
> within the program but I cannot find where to do it in Fox Telem.  There is
> a Funcube control program for Windows but I have not found one for the PI.
> According to the Fauncube site, alignment is required every time you loose
> power to the PI.
>
> Also, I presume that the internet interface for the leader board is not
> supported?  When I click on leaderboard, I get a message that it is not
> supported but when I acknowledge the pop up, the web brouser launches.  It
> does not seem to have this problem when sending or receiving data to the
> server.  Is this normal.
>
> I you would like to call me, my number is 847-514-8566.  Thank you for all
> of the work you put into the Fox in a Box.  If I can fix the DC offset
> problems, I plan to deploy one to Denver, CO and another to McAllen TX.
>
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