Problem with tvrx , wbx and AO-51

GNU Radio
1

Hi,
I have recently got into doing the SDR, i have been using the both the
tvrx and wbx daughter boards for communicating with the ham radio at
435.300Mhz. I am not too good at python so i use GRC. However when i try
to receive from the voice from the AO-51 satellite at the same 435.3Mhz
frequency i dont get anything. Any comments or suggestions are
appreciated.
Thanks & Regards,Naveen

2

schrieb naveen nischal am 2010-06-04 23:49:

Hi,

I have recently got into doing the SDR, i have been using the both the
tvrx and wbx daughter boards for communicating with the ham radio at
435.300Mhz. I am not too good at python so i use GRC. However when i try
to receive from the voice from the AO-51 satellite at the same 435.3Mhz
frequency i dont get anything. Any comments or suggestions are appreciated.

Please take a look at
http://www.amsat.org/amsat-new/satellites/status.php

AO51 seems to work as a repeater/transverter, it never resends the input
at the same frequency/band. Very common is to have the uplink on
2m=145MHz and the downlink on 70cm=435MHz. This is called V/U-mode. You
can find details and the current status at the link above.

Please also take Doppler shift into account, this is not big
show-stopper at FM, but be prepared to retune sometimes. You will see
the Doppler shift if you use a waterfall display.

The easiest to start is to listen first. It’s very probable that you
will hear some conversation during a pass.

Patrick

Engineers motto: cheap, good, fast: choose any two
QTH: JN77rb
Patrick S. OE6PSE

3

Hi All,

I just recorded a 30 degree AO-51 pass over Western Finland using a 1.2
m
RCP Yagi, USRP1, TVRX and TV pre-amp
http://www.vekoy.com/product_info.php?cPath=85_402&products_id=12828

Audio file is located at http://noaaport.poes-weather.com:8081/AO-51/
At 1745Z Tuesday 8th next AO-51 pass will be 70 degrees, I’ll record
that
one also.

Don’t hesitate to ask questions,
Patrik

----- Original Message -----
From: “Patirck Strasser” [email protected]
To: [email protected]
Sent: Tuesday, June 08, 2010 12:50
Subject: [Discuss-gnuradio] Re: problem with tvrx , wbx and AO-51.

4

Hi Naveen,

Which receiver are you using? I use the usrp_nbfm_rcv.py receiver found
in the examples directory
It seems to be transmitting at the moment @ 435.300 MHz,
http://www.amsat.org/amsat-new/echo/CTNews.php

What antenna are you using?

Sample received AO-51 using USRP and TVRX + broadband (TV) preamp
http://www.poes-weather.com/~patrik/AO-51/

Patrik

----- Original Message -----
From: naveen nischal
To: [email protected]
Sent: Saturday, June 05, 2010 0:49
Subject: [Discuss-gnuradio] problem with tvrx , wbx and AO-51.

    Hi,


    I have recently got into doing the SDR, i have been using the

both the tvrx and wbx daughter boards for communicating with the ham
radio at 435.300Mhz. I am not too good at python so i use GRC. However
when i try to receive from the voice from the AO-51 satellite at the
same 435.3Mhz frequency i dont get anything. Any comments or suggestions
are appreciated.

    Thanks & Regards,
    Naveen

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