HF Digital Radio Mondale DRM Stations Copied and Radio / Software Used

[Enigma Explorer]

August 14th 2014 - The last several weeks have been great HF propagation for the most part, and that helps especially for digital modes, such as Digital Radio Mondale. Lets see what we can share with each other for our experiences. Dont forget to include your station details in those reports: Receiver and Software used - Antenna - Station Location - Operator Name  Callsign if you wish, and other special circumstances, such as did you got no audio, occasional audio bursts, full time audio and any digital data that might have been available.

Because of the amount of information one can include about a DRM reception, I have found that the adage that a picture is worth a thousand words really applies here. In most Microsoft Programs is a program called Snipping Tool. It is generally located the Accessories Folder. It is then easy to have several program panels open and arranged on your desktop for easy viewing. Doesnt have to fill your screen. For example I will have open SpectraVue that displays information about the SDR-IQ receiver I use, and the Dream panel and the panel with in Dream called System Evaluation. Once you have the best frequency tuned in that gives the best PPM reading and your best SNR and hopefully with audio being decoded, capture that view and save to an image file. Then share that in your posts. That also does double duty to help others see what settings are working for you.

Now to see if an example image I attach to this pass through to you or not. Unfortuntaly I have had to resize the image to fit the upload limit of 128kb. We need at least twice that - 73 from Bill - WD8ARZ  South Bend, Indiana USA

[Enigma Explorer]

This is an updated version of my previous email on how to get DRM to
work with my SDR-IQ. I downloaded all the latest versions of the
programs discussed below, and all works very well on a Windows 7 Samsung
i7 64bit laptop. Have added additional instructional help based on
questions I have received.

73 from Bill - WD8ARZ
=================

Here is a method to get DRM to work with your SDR-IQ ... or other radio
in many cases.
Have a working SDR-IQ system and software such as SpectraVue.
http://www.rfspace.com/RFSPACE/SpectraVue.htm

Install Virtual Audio Channel (VAC).
http://software.muzychenko.net/eng/vac.htm

There are license free Dream (DRM) of various versions out there on the
net to download, but many of the newer versions with 1.17 and up dont
have audio supported. Have in the past compared version 1.12b and 1.13.
Version 1.17 is by far the better version and has a wider selection of
options. Sourceforge current  version is "
dream-2.1.1win32-svn808-df.zip " and is available for download at the
time of this message. Download from -
http://sourceforge.net/projects/drm/ -  Install Dream and go to the next
step.

Once the correct dll is put into the same directory that Dream DRM is
installed in, there will be audio on DRM signals. I have verified today
with all current versions of VAC, SpectraVue, and Dream that this is a
functional Digital Radio Mondale system as done on my 64bit WIN7 laptop.
Am confident this will also work with XP and VISTA.

To get a working dll file to support the audio, do the following:

Download the Software Radio program file named SoDiRa
http://www.dsp4swls.de/sodira/sodiraeng.html

Inside that program zipped file is a dll named libfaad2.dll. Save this file
some where, and make a copy that you will rename to faad_drm.dll.
It is 232 kb in size. Put the rename file into the root folder with Dream
version 1.17 and you will have a full functional program with audio.

Here is where that info is available, but it is all over the web.
http://yyz-swl.blogspot.com/2012/07/dream-and-libfaad2.html

Have found that audio doesnt always work the first time those files are
installed. They will once you have powered off your computer and
restarted. Once back up and running:

Start VAC control panel. Default settings are fine. Minimize after running.

Start SpectraVue to run the SDR-IQ and configure the output audio to use
Line1 (virtual audio cable) for example. Select WUSB and set it to no
more than 15kHz width, but most of the time I find 12kHz is fine. You
can change any modes bandwidth by using Setup available in lower left
hand portion of the mode panel. Tune in a DRM signal if you can find
one. http://www.drm.org/?page_id=151

I find that the DRM Stations Schedules are incomplete. So I tune the HF
spectrum in such a way that it doesnt take long to tune 2MHz - 30 MHz.
This way I find unlisted DRM signals to explore.

In the SDR-IQ Setup in the top bar, under the left lower corner for the
Filter Bandwidth options, set the Demod Ok option to 190Khz and select
OK to exit. Put the SpectraVue VFO Frequency Tuning Digital display in
to the " Center Frequency - Ins " mode. That option is just to the top
center of the frequency read out digits area of your screen. Select a
frequency of 25.090000. Put your mouse cursor over the 9 in that
frequency read out display. Start rotating your mouse wheel to step down
in frequency in large jumps. This frequency was chosen so I could tell
you where to put your cursor. You can use the digit location for any
band inspection operation you want to start with. When you find a DRM
signal that will look like a broad square wave signal in the spectrum
display, put it into the filter Response area lined up on the right side
of the filter response outline. You can turn on or off that 'Show Filter
Response' outline in the Demodulation Mode Selection (AM, FM, LSB etc
etc panel) Setup option opens a panel for a lot of user choices.
Continue to next step.

Start Dream. Configure Dream to use Sound Card - Signal Input - Device
- Line 1 (virtual audio cable).

Tune in a strong DRM settings in SpectraVue. Better than S7 if you can.
Put DRM wave pattern in to right of center in bandwidth marker guides.

In Dream under View, open the view tab and choose evaluation dialog.
That separate panel will give you the options and displays on how well
it working.

To view and update the station schedule list, under dream panel, select
view tab and choose Stations dialog. That will give you either a old list,
or the option to down load a current list. The panel for the Station
Schedule List will have an update option.

Enjoy and 73 from Bill - WD8ARZ

[Enigma Explorer]

Here is what a typical Digital Mondale radio signal waveform will look. This is the pattern to look for when tuning the hf spectrum for dream. Note that there are other similiar square wave forms to see, but they wont be as wide. Set your program for 12khz wide bandwidth in WUSB mode. That will give you a perspective for the right wave form as you tune through it. 73 from Bill - WD8ARZ