[amsat-bb] Re: M-Cubed telemetry decoded

[Mike Rupprecht]

Hi Carl,

sorry for the delay in answering your questions.

I agree with Henk - the best way to start is with E1P. This cubesat is very
strong and easy to decode. 
Momentarily I use succesful OBJECT F with an center frequency of 437497.5
KHz in USB mode. 
I am sure that E1P belongs to the first cluster (OBJ F and G) but all the
TLE are not very precise (and 2.7 days old).
You can use MixW with standard 1k2 AFSK settings to decode the signal.

A good way is also to record a certain bandwidth - e.g. with the FunCube
Dongle - so you can analyze and decode (manually tune) after the pass.

I use both ways at the same time:

both devices are on the same antenna - a 2x20 el X-Yagi MASPRO with
mast-mounted SSB electronics preamp

1) I track E1P with my FT-736R (antenna and frequency with OBJ F and
software like SatPC32, SATCONTROL or whatever), MixW and virtual port bridge
directly to the E1P decoder software

2) I use a downconverter (High Sierra Microwave 525A-16) together with my
SDR-IQ. So I can see all 4 cubesats at one (beginning from RAX-2 down to
E12P) and can record the complete bandwidth of 190KHz (center frequency
437.425 MHz) without doppler correction.

After a pass I can analyze the 9k6 RAX and M-Cubed packets with AGW packet
engine and my own written KISS software. And I decode the weak AubieSat-1 CW
beacon with my ears (hihi).

I know the second setup is not optimal - because the antenna is pointing to
E1P. Anyway I can decode the M-Cubed packets and RAX packets are pretty
strong.
    

Hope this helps ...

73 Mike
DK3WN




-----Ursprüngliche Nachricht-----
Von: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] Im
Auftrag von PA3GUO
Gesendet: Sonntag, 6. November 2011 13:20
An: amsat-bb at amsat.org
Betreff: [amsat-bb] Re: M-Cubed telemetry decoded

Hi Carl !

 

MCubed & RAX use 9k6, you see that in an SDR, but don't really hear it.

Aubiesat is CW, but relative weak.

 

I would start with Explorer 1.

 

Explorer-1 uses 1k2 and you can clearly hear that in USB or LSB.

Also its signal is relative strong compared to the other sats.

Finally, you can decode it by just playback audio (eg mp3) via MixWin.

It transmits every 15 seconds a burst. Downlink frequency is 437.505 MHz.

 

Step 1: see if you hear it (and let us know - I am interested)

Step 2: decode it

 

Henk, PA3GUO

(antenna: 16 element, horiontal beam, pre-amp: SSB mast-mounted, RX: FCD
SDR)

 

 

>FB Mike.  Could you share which Keps you were using?  Also,  what mode 

>did you use?  What is your setup...radio, TNC, etc?

> 

>I have had no luck with any of the projects.  I would like to try M-Cubed.

>-- 

>*Carl W8KRF*

 

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