[amsat-bb] A tip for Gqrx users and report of the copy of FIREBIRD-II FU3/4 19k2 FSK.
M.Sc. Pavel Milanes Costa
co7wt at frcuba.co.cu
Thu Oct 15 03:24:37 UTC 2015
I'm playing this night with my linux box and rtl-dsr + Gqrx + Gpredict
to see the 70cm satellite sub-band...
And found a way to identify the sat from the spectrum at a glance in
70cm using the bookmarks of gqrx... very handy feature of this
software... just linux here, not know if windows sdr soft has this
After playing with satlist.csv (from
http://www.ne.jp/asahi/hamradio/je9pel/satslist.htm) and parsing it to
make it work with gqrx... I fire the Gqrx software, put up the antenna
and watch for any suspicious signal... and the bookmarks on top of the
signals are there, nice....
... (a few minutes after) ... haja !!!!
A packet like signal around 437.4 Mhz, zoom it.... wow, to wide for
normal packet... let's widen the filter to fit... ~25 Khz is enough,
hum... it's bigger than 9600 bauds... lets see what the bookmarks on the
screenm says... FIREBIRD-II FU4 19k2 FSK within the +/- 10khz of
doppler... bingo !!!
Let's run Gpredict to check.... right on the spot... and also
FIREBIRD-II FU3 incoming on range... let's check... right...
So if you use linux and some SDR hardware with Gqrx, you can use the
bookmark function to this purpose, you can actually click & zoom and
then read of the screen to approximate which is the satellite who tx
that signal... all at a glance...
If any of you want to play with this I can send you my bookmark file of
the entire 70cm satellite sub-band, updated with the last info from
http://www.ne.jp/asahi/hamradio/je9pel/satslist.htm just email me a
I was not trying to decode, just to prove the usefulness of this
feature, I use the latest gqrx & gpredict from ubuntu PPA.
BTW, none of the FIREBIRD satellites are in the
http://www.amsat.org/status/ page, so I can't update it's state.
73 from Cuba, CO7WT
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