Just spoted GOMX-3 right now using this method... sat hunting is fun... 73

PS: not in http://www.amsat.org/status/ listing also...

73

El 14/10/15 a las 23:24, M.Sc. Pavel Milanes Costa escribió:

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 feature...

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 private msg.

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 _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

Hi, some users have asked for pictures of this... so I share this on the BB

Thanks to Scott (K4KDR) that put them on-line for me (I have internet problems here at the moment)

=========

Partial satellite sub-band in view, it's bigger than the BW of the RTL-SDR https://www.dropbox.com/s/f0dsrdfspz4dhw6/Full%20satellite%20sub-band%20in%2... ========= Tracking Cute 1.7 (sat not in range) + Gpredict control https://www.dropbox.com/s/argg4va9xudjo47/Tracking%20Cute%201.7.png?dl=0 ========

Tracking phonesat 2.4 (no signal, end of the pass) https://www.dropbox.com/s/kewdqkyga1x3xl2/Tracking%20phonesat%202.4.png?dl=0

======== Tracking phonesat 2.4 wide https://www.dropbox.com/s/smoabjs9nuq3xhz/Tracking%20phonesat%202.4%20wide.p...

========= Tracking phonesat 2.4 wider... https://www.dropbox.com/s/vx8frrzx8uiicoo/Tracking%20phonesat%202.4%20wider....

========

Detail of two signals in the spectrum; the left is a terrestrial signal (commercial?: more than one TX site/signal level, always there, no doppler) and right is unknown...

https://www.dropbox.com/s/f8eleb1qobzr6dw/Two%20not-noise%20signals.png?dl=0

========

With this I see that there are some withe spaces on the sub-band, I have to check the band plan of the IARU...

Enjoy, 73.

PS: antenna is a homebrew RHCP QH and homebrew preamplifier (not worth to name it as "LNA", it's quite noisy but do the job....)

El 14/10/15 a las 23:24, M.Sc. Pavel Milanes Costa escribió:

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 feature...

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 private msg.

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 _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb