[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss-gnuradio] Help decoding Bell 202

From: En Shih
Subject: [Discuss-gnuradio] Help decoding Bell 202
Date: Sun, 27 Dec 2015 05:52:03 -0700 (MST)

Hi all,

I am trying to decode a Bell 202 signal from a RTL dongle source using GNU
Radio Companion
I am new to GNU Radio and signal processing, and constructed this flow graph
by searching previous topics on AFSK:

first by passing through a NBFM and then a quadrature demod, but I can't
recover the expected signal, which should have bytes 01 04 or 01 01 at the
start of a packet.

This is how the signal looks like:

1. RTL-SDR source

2. After NBFM receive

3. After quadrature demod

4. Final

Does it look like I am on the right track? 

The grc file, a dump of the original signal, and a decoded file is stored
The decoded file was done using a physical modem, and its contents does not
match the dump but is in the same format.

I have also tried using  multimon-ng
<https://github.com/EliasOenal/multimon-ng>   with the following command:
rtl_fm -f 402000000 -s 22050 | multimon-ng -a AFSK1200 -t raw /dev/stdin 
but to no avail.


En Shih

View this message in context: 
Sent from the GnuRadio mailing list archive at Nabble.com.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]