[amsat-bb] FUNCube-1 (AO-73) Telemetry via FO-29??

Dani EA4GPZ daniel at destevez.net
Fri Aug 12 16:33:09 UTC 2016

El 12/08/16 a las 17:29, Zach Leffke escribió:
> Hi Dani,
>     Great questions.  On my long list of 'TO DOs' for the VTGS is to get
> our github account up and running to push our satellite GNU Radio work
> back out to the Open Source community.  Once we do I'll post the code
> along with the pyBOMBS recipes for installation.  I don't have an ETA
> for that though (maybe this Fall semester.....?).  There are a few other
> things in the Out of Tree Module that would be of use to Hams as well. 
> For example we have scramblers and descramblers that are AX.25
> compliant.  We also have an AFSK TRANSMITTER as well as an AFSK receiver
> (I've seen a few AFSK/AX.25 GNU Radio projects, but they are all
> receivers and they don't separate the demodulator from the link layer
> protocol).

Hi Zack,

Looking forward to it, as this will be useful for me and probably other
hams. I understand that it is a bit of work to clean the code up to push
to github.

In fact, I also have my own AFSK/AX.25 GNUradio transceiver in github,
as I wasn't too happy with any of the other projects (it also does FSK
and BSPK, which is useful for QB50p). For AX.25 (de)scrambling I use the
default GNUradio blocks. They can be used if you understand what
parameters you need to put.

In case anyone is interested:



> The AO-73 dashboard also does the Automatic Frequency Correction,
> which is something we don't quite have implemented in our GNU Radio
> flowgraphs yet (we tune either manually or via a Gpredict interface to
> GNU-Radio to get inside the capture bandwidth of our differential bpsk
> demod).

It's not as good as the software in the dashboard, which will search for
the signal in all the passband and track it, but in GNUradio you can use
FLL band edge, which will correct mistunings of up to a 1 or 2kHz.
Together with Gpredict, this usually solves all tuning problems.
Probably you already knew this.

> Something that would make a good comparison easier to implement, and
> that I would like to see, is a Linux version (and open source) of the
> FunCube Dashboard.
> That's one of the things
> I really like about the AO-85 dashboard is the cross-platform support.

Same opinion here. For me it's a hassle to run the dashboard inside a
virtual machine, if only because I have to feed it the audio via wav
files. Between linux programs I can use pulseaudio to exchange real time


Dani EA4GPZ.

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