Wednesday, August 12, 2009

Dream a little DRM

Recently on the Flex list there has been quite a bit of interest in DRM aka Digital Radio Monidale

DRM is a modulation scheme that is a digital signal that can contain a variety of data including audio and text. The Wikipedia entry gives a good description. I had DRM running on my SDR-1000 several years ago, and basically had forgotten it. With all the interest I decided to see just how easy it would be to set up DRM on my F5K. What I discovered is that it is trivial

I downloaded the DREAM decoder from this website

I installed the .zip file into a folder and started the DRM decoder

Next I set up the I/O in the F5K and the DRM decoder

Finally I found a program guide of DRM stations and tuned in Vatican Radio ata 9800 in the 31M shortwave band. The F5K has a mode devoted to the DRM mode. As soon as I tuned in the station I started decoding

Here is an example of the raw audio from the F5K headphones and here is the audio output in my computer speakers. The audio quality is virtually like FM radio with no fading at all

I have read on the flex list you can also use the F5K as a experimental DRM transmitter using a DRM encoder, but I haven't really investigated that at all.

So if you have a Flex download the decoder and have a blast!!!