Re: [Discuss-gnuradio] DReaM and gnuradio

[Eric A. Cottrell]

Charles Swiger wrote:
> Hi Gang - Did somebody have the DRM decoder working with a gnuradio
> receiver? The main issue is feeding the sound from gnuradio into DReaM,
> somehow, other than using two soundcards.  I have DReaM 1.6.25 compiled.
> 
> http://sourceforge.net/projects/drm/
> 
> TIA
> 
> --Chuck

Hello,

I am setting up the DReaM decoder using the USRP.  I am gradually
getting it to work and managed to copy Radio New Zealand this morning on
9690.  I was using the "No-Mod" DRM Mod for the AOR 5000 but found I
needed a very good signal to get anything.

I am using the 10.7 MHz IF out of my AOR 5000 reciever connected to the
USRP with Basic RX via a torroid transformer.  The transformer was
originally used to cut down noise but I had to make it a step-up
transformer to increase the signal level.  The secondary is connected to
RX A and RX B as a differential input.

I used similar code to what was posted on the list in 2005 to convert
the 10.7 MHz to baseband.  I resample the baseband from 64000 samples
per second to 48000 samples per second and output it to a Griffin iMic
USB Audio dongle.  I am outputing "stereo" (I/Q).

I am going to try using Jack to loopback the audio but currently I am
looping the iMic output to the iMic input.  DReaM is setup to use I/Q by
using the -c 4 parameter.  I use -c 4 because the IF Output spectrum is
inverted.  DReaM outputs to my main speakers on the laptop.

The laptop I use does not have line in so I use the iMic for other
decoding and get two outputs in the process.  The iMic is not very
expensive but using jack is even cheaper.

73 Eric