DRM - Digital AM radio below 30MHz
             
       AOR (UK) Ltd
         
         Unit 9, Dimple Road Business Centre, Matlock, Derbyshire DE4 3JX, 
      England
      Tel: +44 (0) 1629 581222  Fax: +44 (0) 1629 580070

DRM - Digital Radio Mondiale - Digital AM radio below 30MHz
  General information and transmission schedules

    DRM SPECIFICATION 
    AOR AR7030 for DRM operation 
    AOR AR5000 for DRM operation 
    TenTec RX320 for DRM operation 
    TenTec RX340 for DRM operation 
    TenTec RX350D for DRM operation 
    Deutsche Welle: Digital shortwave broadcasts to begin in June 2003  
    DRM update - international broadcasting AIB News March 2003 
    AR7030 employed by the BBC for DRM evaluation 
    KITS & modifications 
    DRMRX - New web site - FRAUNHOFER SOFTWARE DECODER 
    IBOC digital transmissions in the USA 
    New Zealand DX Times - May 2003 
    DRM bench testing 
    Coding Technologies / Mayah Comms - press release UK Electronics Weekly 
    17/09/03 P14 (103kb JPG) 
  On March 7 / 8 2003, the SWL fest outside of Philadelphia USA demonstrated 
  DRM.  For a report, take a look at the following feature on MSNBC News  
  http://www.msnbc.com/news/krakow.asp  



General information and transmission schedules
Extensive information was placed on this page during September 2001 following a 
trip to the IFA-2001 in Berlin.  However, the subject and technology moves on 
and the information becomes out of date (links fail etc).  For this reason, we 
have removed the contact and suggest that you visit the DRM consortium pages for 
background information www.drm.org
  Digital Radio Mondiale, DRM Project Office
  17a Ancienne Route
  1218 Grand-Sacconex
  Geneva
  Switzerland
  Tel: +41 22 717 27 18
  Fax: +41 22 747 47 18
  projectoffice@drm.org     
  www.drm.org 
The Fraunhofer Institute in Germany is also a member of the DRM consortium and 
is the driving force in respect of the protocols employed by DRM and authoring 
of PC demodulation software, they have been instrumental in the modification of 
the AOR AR7030 receiver for extensive DRM use during the DRM evaluation phase.  
Two software packages have been produced by Fraunhofer:
  * Professional version with statistical data, contact Fraunhofer directly for 
  price
  * End user basic DRM demodulator, distributed by VT Merlin, see DRMRX site - 
  details below:
  Fraunhofer Institute
  For Integrated Circuits IIS-A
  Applied Electronics
  Am Wolfsmantel 33
  91058 Erlangen
  Germany
  Tel: +49 81 317 76 63 27
  Fax: +49 91 317 76 63 99
  bc-info@iis.fhg.de  
  www.iis.fhg.de  
DREAM SOFTWARE
An alternative FREE software package is also available, this being Open-Source 
Software Implementation of a 
DRM-Receiver Under the GNU General Public License (GPL).  Take a look at the 
following page:
http://www.tu-darmstadt.de/fb/et/uet/fguet/mitarbeiter/vf/DRM/DRM.html 
Mark Philips retorted on the RX320 Yahoo group on 9 May 2003 that a compiled 
copy of DREAM software can be downloaded from 
http://www.g7ltt.com/drm/software/DReaM.zip 
Radio Netherlands is also a consortium member and lists the DRM transmission 
schedules on its web site.  
Have a look at the following links 
http://www.rnw.nl/realradio/html/drm_latest.html and 
http://www.rnw.nl/realradio/html/drm.html 
Take a look at the following link for up-to-date information 
http://www.wwdxc.de/drm.htm 
  Another useful information site for DRM is 
  http://digital-radio-mondiale.wikiverse.org/  
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DRM SPECIFICATION
Gerd Kilian (Fraunhofer Institute, October 2001) advised us that the DRM 
SPECIFICATION is available as a free Acrobat PDF download from the ETSI web site 
(its just over 1MB in size).
GK FhG:  The DRM specification is now available for download from the ETSI 
server www.etsi.org.  Follow the links to the download area and put "drm" as the 
search string. You can then download the specification for free. If you have not 
registered on the ETSI website you will need to do so. It takes a few minutes 
only.

We note that once registered, the ETSI site only permits three file downloads 
before a fee is payable (use it sparingly).  The URL for the download appears to 
be: http://pda.etsi.org/pda/queryform.asp  Although this URL will take you 
directly to the file area you require, it will invoke the REGISTRATION process 
when you attempt to download... after which you are returned to the correct 
location once again.
Don't type DRM on the main home page of ETSI or it will find too many unrelated 
files, only type DRM in the search section of the DOWNLOAD page.
The home page of the ETSI site is: http://www.etsi.org 
A DRM broadcasters user manual has been published (May 2004) 
http://www.drm.org/BUM/globbum.htm 
The Acrobat PDF information requires Acrobat Reader to view and print, a free 
copy is available from the
Adobe web site http://www.adobe.com/ 
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AOR AR7030 for DRM operation
The AR7030 was selected by Fraunhofer due to its high performance (excellent 
strong signal handling and low phase noise), good AGC action and ease of 
modification.  Of course the balance of price and performance was the deciding 
factor too!
Here at AOR UK, we have the capability to generate and air-test DRM using 
software pre-released from the developers (Fraunhofer). However, customers in 
possession of DRM capable equipment need to purchase a licence and download the 
software from the DRMRX web site, see below.

Modification involves making use of the two free filter positions of the AR7030 
(so 4 user and 2 DRM positions are used). If considering retro-modification and 
have optional filters already fitted, they would have to be removed. Performance 
is  theoretically slightly compromised by the modification, but not measurably 
so in the real world.

You need to use a computer and software for DRM decode, demodulated audio will 
not be produced by the AR7030 internally.

Sony is one of the consortium members and is planning a stand-alone receiver for 
release at the end of 2003/2004, there are still merits for a quality desktop 
unit for DXing.
It is unlikely that a DRM 'kit' will be marketed by AOR as modification to the 
radio is also required along with some alignment checks and re-calibration of 
AGC, so the potential for damage or failure is quite high by self-modification. 
However, we can now offer a tested DRM receiver or retro-modification.
Prices in the UK are as follows (inc VAT):
            AR7030 standard unitGBP 799.00 inc VAT
            AR7030 DRM modifiedGBP 949.00 inc VAT
            AR7030 PLUSGBP 949.00 inc VAT
            AR7030 PLUS DRM modified GBP 1,099.00 inc VAT

      Retro-DRM modifications will be charged at GBP 200.00 inc VAT, carriage 
      extra.
      The circuit information regarding the DRM modification is supplied with 
      each DRM modified AR7030 receiver.  A copy of the two page Acrobat PDF 
      file is available for you to view (31kb)... we have removed the company 
      logo and watermark so that it can't be used as a cover-note for private 
      modifications !
        WIDE DRM use with the AR7030 (20kHz) 
            A few broadcasters have asked about WIDE bandwidth DRM reception 
            using the AR7030.
            The problem of wide DRM is in obtaining HIGH QUALITY crystal roofing 
            filters in small quantities... we find the existing 15kHz filter was 
            one of the 'most fussy' components in respect of final IP3 
            characteristics of the entire receiver.  For this reason we have not 
            modified / tested the AR7030 for wide bandwidth use.  It is assumed 
            that we would need to change the crystal roofing filters and at 
            least one 455kHz tail filter... the receiver's architecture would 
            place the filters out-of-sequence in bandwidth listing but this 
            would not affect DRM operation.
            Our engineer's comments are as follows...
            The DRM modified receiver is designed for operation on 9kHz / 10kHz 
            transmissions. If 20kHz DRM signals are to be monitored, the 45MHz 
            IF crystal roofing filters would need to be replaced, these are not 
            available in small quantities so we cannot offer a 'wide DRM 
            modification at this time. The switchable 455kHz filters and the 
            455kHz tail filter (fixed for AM purposes) would also need to be 
            replaced.

            Bandwidths for the standard unmodified AR7030 are as follows;

            45MHz IF (45M15) crystal filter pair:
            +/-7.5kHz (3dB).

            Switchable 455khz ceramic filters:
            455F +/- 6kHz (6dB) or 455D +/- 10kHz (6dB).

            Tail filter 455kHz:
            455C +/- 12.5kHz (6dB).

            Given the band width of the wider of the switchable filters (ignore 
            the 9.5kHz displayed filter, this is actually +/-4.5kHz), the main 
            restriction to band width is the 45MHz crystal filter pair and 
            possibly to some extent, the switchable 455kHz filter.

            If the crystal filters overall 15kHz is not wide enough given the 
            allowed degradation at the signal edges, it would be easy to widen 
            the band width with the use of 45M20 xtal filter pair to open it up 
            to an overall 20kHz. Similarly, the 455D could be replaced with a 
            455C.

            Similarly any of the other filters could be substituted for wider 
            versions if required. If DRM performance is the only criteria, then 
            it should be possible to tailor it to whatever is required (assuming 
            the filters can be obtained in very small quantities).

            As comment here is untested, it is very much on a 'try it and see' 
            basis.

            Further comment...
            The AR7030 was originally designed with SW listening in mind. The 
            assumption being that people would be concentrating on fitting 
            narrower bandwidths rather than wider ones (not that wider ones 
            cause any problems). The set was therefore configured with a 2nd IF 
            of five moveable filter positions and one fixed filter. The fixed 
            filter being approximately 9.5kHz wide.
            The sets software/firmware will always place this fixed filter as 
            the last filter and label it as 9.5kHz. So even if it is not the 
            widest filter fitted to the set it will always come out as the last 
            filter after a filter calibration has been run (i.e. filter no. 6 in 
            your set).

            Any other filters fitted will then calibrate and be allocated a 
            filter position in ascending bandwidth below the 9.5kHz filter. This 
            will always be the case.
            The five 'moveable' filter positions are allowed to display a value 
            between 0 and 6.6kHz even if of wider bandwidth than 6.6kHz (filter 
            performance is not affected by this even if wider bandwidths are 
            fitted)

            So even if a 20kHz filter is fitted in one of the five filter 
            positions, it will still only display 6.6kHz and get a filter 
            allocation below the 9.5kHz filter.

            Until DRM was introduced, this setup worked really well as no-one 
            ever used wider filters and the system overcame problems when 
            fitting unusual specification and non AOR filters. It makes the set 
            very versatile for normal SW use.

            The DRM modification design and component choice was done completely 
            external to AOR, by the Fraunhofer Institute in Germany. We simply 
            supply the modification as designed and specified by Fraunhofer.

            Amongst the component changes, the sets overall bandwidth is opened 
            up by replacing the 9.5kHz AM tail filter by a 24kHz wide ( +/- 
            12kHz ) filter (don't confuse this with the 9.5kHz filter mentioned 
            previously). The first IF is fixed and limited by a filter pair of 
            15kHz (+/- 7.5kHz).

            The other additional DRM filters added are a 12kHz (+/-6kHz) item 
            and a 20kHz (+/-10kHz) item, fitted in two of the five moveable 
            filter positions.

            These two filters are already wider than the fixed 9.5kHz filter 
            (F6) but they will always be displayed as F4 and F5 and show a 
            6.6kHz bandwidth.

            Incidentally, the unmodified filter F3 is a nominal 6kHz filter and 
            will tend to display between 6kHz and 6.6kHz (so in some sets this 
            may also show as 6.6kHz).

            In short, although several filters may show the same displayed 
            reading, the set will always put them in correct ascending bandwidth 
            with the exception of the 9.5kHz filter which will always be placed 
            in the highest filter position.

            In a DRM modified AR7030, the widest filter position is allocated by 
            the set as F5. Here the changeable 2nd IF filter is 20kHz wide, the 
            tail filter is 24kHz wide, but the limiting filter is the 1st IF 
            filter pair at 15kHz. Therefore altering the changeable IF filter to 
            an even wider one would be pointless without considering replacing 
            the 1st IF filter pair.

      AOR does not provide modification kits - no exceptions, see below.
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      AOR AR5000 for DRM operation
      The AR5000 was evaluated for DRM operation by The Fraunhofer Institute in 
      Germany, it appears that they used the 10.7MHz IF output.  However, they 
      opted for the AR7030 because it was easily modified and provided superior 
      strong signal handling and phase noise.
      A few customers of AR5000 receivers have experimented with good results.  
      In particular Francois Michaud-Herbst <Frmichaud@compuserve.com> of Canada 
      has provided two reports on his tests:
      AR5000 without modification - Acrobat PDF file 224kb
      AR5000 with 10.7MHz IF down-converter hardware - Acrobat PDF file 292kb
      He will next try DRM using the 455kHz output... see technical bulletin
      Top 



      TenTec RX320 for DRM operation
      A new version of RX320 has been produced from April 2003 which has a 12kHz 
      I.F. output for DRM use via a PC sound card and Fraunhofer software.  The 
      new model is the RX320D, for details relating to DRM operation with the 
      RX320 - click here.  This includes information regarding 
      retro-modifications to existing units.
      As the RX320 has a 12kHz final I.F., it has been assumed for some time 
      that the RX320 may be ideally suited for DRM use, the text below is now 
      rather historical but contains interesting technical details.
      There have been many enquiries regarding the suitability of the TenTec 
      RX320 for DRM reception using the Fraunhofer software decoder.  As the 
      RX320 has an IF of 12kHz (where the DSP is implemented), it made an 
      interesting project for testing.  Below is the summary of findings by the 
      UK workshop.
      The RX320 is conveniently designed so that the output from the main 
      receive (top) board is at 12kHz. Its suitability for DRM has been briefly 
      checked by disconnecting the output feed from the mini coax connector at 
      the rear of that board and plugging in a lead from the PC sound card 
      directly into the socket. The output to this socket is capacitively 
      coupled 
      so there is no need to worry about floating DC voltages. Doing it this way 
      has the disadvantage that no signal is then being passed through to the 
      DSP section of the radio. Ideally a separate capacitor feed could be taken 
      from pin 1, IC U4A (TL082).

      The output was taken to the sound card mic' input to allow some control of 
      the input level.

      The signal monitored was instantly decoded producing intermittent audio 
      from a very marginal signal (The AR7030 DRM producing similar results). In 
      a period of clear signal reception, a good, uninterrupted period of audio 
      was decoded with no obvious problems. The output wave form appeared not 
      quite as clear (steep sided with flat top) as that produced by the AR7030 
      but it was quite reasonable and perfectly usable.

      At the point that the 12kHz signal is taken from in the RX320, the signal 
      passes through two filters, one at 45MHz and the other at 455kHz. Both of 
      these filters are 15kHz wide (giving a bandwidth somewhere between the two 
      DRM filter bandwidths fitted to the AR7030).

      In practice, with AM selected, the receiver 1st Local Oscillator steps in 
      2.5kHz steps (the finer steps are done later in the DSP section so don't 
      concern us for DRM use). This leads to a tuning frequency error up to 
      +/-1.25kHz. On top of this, this LO is offset by 2.5kHz This doesn't seem 
      to be a problem through the 15kHz filters. This offset also appears to be 
      corrected to a large extent by the time the signal reaches the 12kHz 
      output due to the 2nd LO and BFO injections.

      Any small frequency error due to drifting of the 1st LO also tends to be 
      cancelled out by the time it reaches the 12kHz output. 

      With the tuning error of +/-1.25kHz, the 12kHz signal we are tapping off 
      should theoretically tuning between 10.75 and 13.25kHz. In practice on the 
      set I tested, this was actually 10.625 to 13.125kHz (125hz offset). With 
      the overall bandwidth somewhere in the region of 15kHz (ie. +/- 7.5kHz 
      either side the theoretical 12kHz signal), this doesn't appear to cause 
      any great problems for the DRM software.

      Note; It is irrelevant which filter bandwidth is selected on the radio 
      control software as this filtering is carried out in the DSP section.

      AM was the mode selected during testing. Again this is more or less 
      irrelevant as any demodulating is carried out at DSP level. The only point 
      worth noting here is that if SSB was selected, for our purposes, the 
      receive frequency will be same as if AM was selected in the narrowest 
      selectable bandwidth but with a wider bandwidths, a +/-5kHz offset occurs. 



      RX320 tuning frequencies:  The RX320 has three IF frequencies, 45MHz, 
      455kHz and 12kHz. 

      The first IF signal is obtained by mixing the receive signal with the 
      tuneable 1st Local Oscillator. This oscillator steps in 2.5kHz steps (the 
      finer steps are done later in the DSP section). In AM, this leads to a 
      tuning frequency error up to +/-1.25kHz. On top of this, this LO is also 
      offset by 2.5kHz In SSB, the 1st LO frequency is the same when the 
      narrowest bandwidth is selected but changes as the bandwidth is opened up.
        In LSB, LO frequency shifts between 0 and -5kHz with bandwidth.
        In USB, LO frequency shifts between 0 and +5kHz with bandwidth. 
      The second IF is then obtained by mixing with the 2nd Local Osc'.  This is 
      a fixed oscillator regardless of mode or band width selected.

      The BFO signal mixes with the 2nd IF to produce the '12kHz' output used by 
      the DSP. The BFO signal appears to be fixed.

      In AM, by the time the signal reaches the 12kHz output point, the Offset 
      produced by the 1st LO appears to be corrected to some extent by the 2nd 
      LO and BFO signals. 

      In theory, with the potential tuning error of +/- 1.25kHz at this point, 
      the signal present should be between 10.75kHz and 13.25kHz.

      On the set tested, a small error of 125hz still remained giving a range of 
      10.625 to 13.125kHz. 

      Any small frequency error due to drifting of the 1st LO also tends to be 
      cancelled out by drifting in the opposite direction by the other 
      oscillator. 

      Both 1st and 2nd IF filters are 15kHz wide. Any offsets or tuning error is 
      therefore relatively unimportant for receive purposes. Narrower filtering 
      and finer tuning is carrier out later on in the DSP section.  
        
      The TenTec RX-320 was displayed at the SWL exhibition outside of 
      Philadelphia on 7 & 8 March 2003 by Lee Reynolds.  Lee was using his own 
      RX320 and had access to the WinRadio G303i provided by Monitoring Times, 
      the AOR AR7030 was on display too (AR7030-DRM provided by AOR UK LTD and 
      displayed by Kim Elliott of VOA NEWS)... all using Fraunhofer DRM 
      demodulation software. DRM signals were made available for demonstration.  
      Lee's comments are given below: 
      I knew that the '320 had a 12kHz (app.) IF available and had been 
      pondering the doability of the job for a while. It wasn't until the 
      Fraunhofer consumer-level package was released that I decided to go after 
      the thing. Your site's notes where you detailed tentative digging at the 
      '320 confirmed my suspicions and I had a test tap in place feeding the 
      Fraunhofer code in no time. Used a .1 ceramic for blocking/decoupling and 
      pin 1 of the TL082. Once I'd established functionality and usability of 
      the signal I just added a phono jack to the '320 rear apron. Results seem 
      to be pretty good overall and it provides a clean signal to the Fraunhofer 
      code. I'd say that it performs at least as well as the G303i.  
      I'm reviewing the 303i versus the 320 for Monitoring Times over here so I 
      bought the test 303i along to the 'fest. I'd also previously tested this 
      combo at home. I fed the 12kHz audio/IF signal from the 303i directly into 
      the sound card running the Fraunhofer software. Again, a decent signal was 
      provided by the receiver and good audio was obtained. The Win people don't 
      yet have their own decoder. Someone did observe that on occasion the 303i 
      seemed to intermittently provide a less than optimal SNR for reasons 
      unknown.  
      Also check the upcoming edition of Monitoring Times - there'll be a 
      technical article on DRM in 
      there with a "Dummy's Guide" by me as a tailpiece to it.  
      Lee Reynolds, USA 13 March 2003 
      For a report on the show, check out http://www.msnbc.com/news/883723.asp  
        
      RX320D 
      Following release of the RX320D (version with DRM 12kHz IF socket), there 
      has been some speculation that changing a capacitor in the AGC circuit mat 
      improve DRM performance.  TenTec USA say: 
        The component change is intended to slow down the AGC activity so it 
        can't wash out the 
        amplitude variations in the DRM signal. Changing C81 on the the RF board 
        from 4.7 uF to 33 uF 
        made a measurable difference in the decoding performance of the DRM 
        software. The downside is 
        that it will also slow down the overall analogue AGC rate. It may 
        adversely affect other modes of 
        operation but only some airtime will prove that. On the schematic (page 
        3 of 3 of the RF section) the cap is about dead centre.  
      There have been mixed reports regarding an improvement by changing C81... 
      it has not been implemented into production or retro-modification. 
      Several people (especially when laptop computers are used) have 
      experienced too much level into the sound card (2V p-p).  Adding a 
      potentiometer with the slider toward the computer may help... take a look 
      at the illustrated modification at http://www.g7ltt.com/drm/rx320mods/  
      A recent article in Electronics World magazine (2003) regarding the RX320 
      and DRM suggested that due to the PLL tuning increments of 2.5kHz (see 
      above) that DREAM software may be more versatile than Fraunhofer for 
      monitoring certain less common frequencies.  Take a look at the comparison 
      table (Acrobat PDF file, 112kb) - click here. 
      RETRO-MODIFICATION 
      It is possible for the RX320 to be retro modified to provide a 12kHz IF 
      output socket for DRM use, we change the RF input transformer T3-21255 at 
      the same time for improved performance of MW, a few pages of addendum are 
      included.  The cost is GBP 25.00 inc VAT (to cover labour & parts), 
      carriage is extra - typically GBP 12.00 inc VAT to UK mainland addresses 
        
      RX320 hardware front panel 
      While on the subject of the RX320, Giuliano I0CG has announced that he is 
      independently designing a hardware front panel for control of the RX320 
      without the need for a computer: 
        Subject: [RX320] re:RX320 hardware panel available (v1)
        From: giulianoi0cg <giulianori@libero.it>
        Date: 12 July 2003 00:21:29
        The ten Tec RX320 hardware panel is working !  With this panel a PC 
        isn't necessary!  If are you interested see my web page  
        http://it.geocities.com/giulianoi0cg/rx320_page downlod the operation 
        manual "panel_rx320.zip"

        Rregards
        Giuliano I0CG
        Italy
      Top 



      TenTec RX340 for DRM operation
      Several receives with 455kHz I.F. outputs have been successfully employed 
      for DRM demodulation by down-converting the I.F. to 12kHz and Fraunhofer 
      PC software via a sound card.  However, TenTec USA has found that 
      successful results can be obtained WITHOUT any hardware modification at 
      all... you just need to set up the RX340 appropriately:
      Select USB mode on the RX-340, and set the bandwidth control to 16 kHz.   
      Turn the PBT control to +2 kHz.  Offset the receiver -12 kHz from the 
      nominal carrier frequency.  Example: there are currently test broadcasts 
      of DRM on 9660 kHz.  After setting the above, tune the receiver -12 kHz to 
      9648 kHz. 
      Load the DRM software, connect a line level audio output on the RX-340 to 
      the sound card on your PC, and you're ready to decode the transmissions.
      The audio output is fed into a PC sound card and Fraunhofer software is 
      used to demodulate the data into audio via the PC sound card and speakers. 
       The software is available as a download from the DRMRX web site and costs 
      around  40 / EU 60 / US$ 60. 
      For further information regarding DRM and obtaining the Fraunhofer 
      software, also have a look through the rest of THIS PAGE.
      For product information, please refer to the RX340 page of the TenTec UK 
      web site.
      Top 



      TenTec RX350 for DRM operation
      A new version of RX350 has been produced from 2003 which has a 12kHz I.F. 
      output for DRM use via a PC sound card and Fraunhofer software.  The new 
      model is the RX350D.  Further information can be viewed - click here
      RETRO-MODIFICATION 
      It is possible for the RX350 to be retro modified to provide a 12kHz IF 
      output socket for DRM use.  This is a relatively straightforward process 
      and several people have documented the changes on their web site, one 
      example being http://home.satx.rr.com/ka5jgv  
      We can modify the radio in our UK workshop, the cost is GBP 25.00 inc VAT 
      (to cover labour & parts), carriage is extra - typically GBP 12.00 inc VAT 
      to UK mainland addresses 
      Top 



      Deutsche Welle: Digital shortwave broadcasts to begin in June 2003  
      AIB International Broadcasting news - February 2003 
      At the official launch of DRM at the World Administrative Radio Conference 
      in June 2003, DW will first initiate digital shortwave programmes in 
      Europe and the Middle East. The required conversion of two transmitters at 
      the relay station in Sines, Portugal will have been completed by then. 
      From June 2003, DW plans to broadcast 8.5 programme hours daily in the DRM 
      standard in German, English and Arabic to the target regions of Central, 
      Eastern and Southern Europe as well as the Middle East. 
      The second stage will expand the programme hours and languages for these 
      target regions and introduce additional programmes for Asia. For this 
      purpose, according to DW Director Erik Bettermann, a transmitter at the 
      relay station in Trincomalee, Sri Lanka, will be converted by 2003, making 
      it possible to receive a total of six daily programme hours in German, 
      English, Bengali, Urdu, Pashto and Dari in Asia. The Director General 
      stressed that realization of the planned DRM launch is subject to DW's 
      budgetary situation.
      If market developments allow, DRM broadcasts are planned for America in 
      the year 2005. This would require that further transmitters - for example 
      in Antigua and Kigali, Rwanda - are converted. Bettermann explained that 
      establishment of the new technology on the market will require that many 
      radio stations broadcast in DRM in the same target region and that the 
      market offers suitable receivers at affordable prices.
      The long-term strategy of DW for the launch of DRM broadcasts will be 
      aligned to that of the DRM Consortium and its members as well as other 
      radio stations. "In a unifying Europe we must attempt to optimise the 
      transmission capacities of larger international broadcasters by forming 
      European programme groups," said Bettermann. 
      http://www.dw-world.de/english   
      Top 



      DRM update - international broadcasting AIB News March 2003
      After long years of gathering a consortium, prototyping and testing, DRM 
      announced that there would be an official launch at the World Radio 
      Conference in Geneva, in June. DRM is the worlds only non-proprietary, 
      digital system for short-wave, medium-wave and long-wave with the ability 
      to use existing frequencies and bandwidth across the globe. With near-FM 
      quality sound, DRM aims to revitalize the AM broadcasting bands below 30 
      MHz in markets worldwide. Hard on the heels of the launch announcement 
      came the granting of two highly significant standards for DRM.  
      Firstly, the International Electrotechnical Committee (IEC) has given the 
      Digital Radio Mondiale on-air system its highest stamp of approval  
      International Standard. And then the International Telecommunication Union 
      (ITU) gave permission for any broadcaster to use existing frequency 
      assignments for DRM digital transmissions, provided that there is no 
      interference with other stations. 
      So DRM is well on its way. The aura of success was embellished with the 
      news that AIB member Radio Sweden will start broadcasts using the new DRM 
      digital format on 16 June. The new transmissions will be via another AIB 
      member Radio Canada International, which is already relaying Radio 
      Swedens English and Swedish broadcasts to North America from their 
      transmitter station at Sackville (in return for RCI relays from 
      transmitters in Sweden). RCI will be carrying a number of digital English 
      language programmes from various international broadcasters. The other 
      stations 
      expected to take part are the BBC, Radio Netherlands, Vatican Radio, Radio 
      Japan and China Radio International. The only remaining question is of 
      course a small but totally encompassing one  after all this, will there 
      be an audience? Will DRM receivers be out there, at the right price, in 
      sufficient quantities? Its a question which has bedevilled all new system 
      operators, such as DAB, WorldSpace, XM, and Sirius, and continues to 
      bother them years after launch. 

      Deutsche Welle
      DW will be transmitting some programmes in digital, but meanwhile, some 
      rationalisation has taken place in other areas. Starting at the end of 
      March, the DW English Service will increase news bulletins and news 
      programmes, but while digital shortwave transmissions to East Asia and 
      Europe will be introduced, and analogue shortwave transmissions to Asia 
      and Africa continuing for the foreseeable future, there will be shortwave 
      cuts. Shortwave broadcasts to the highly developed media markets of North 
      America and Australia and New Zealand will be terminated. Instead, DW 
      will focus on expanding the number of rebroadcasters. 
      Top 



      AR7030 employed by the BBC for DRM evaluation
      The following information has been provided by the BBC following display 
      at the IBC in Amsterdam 2002.  The material and photograph is (c) 
      copyright BBC R&D 2002 and presented here by their kind permission.
      BBC Research & Development engineers recently adapted one of our AOR 7030 
      receivers for a demonstration of DRM reception at the International 
      Broadcasting Convention in Amsterdam. They modified the 7030 to be a 
      stand-alone DRM receiver by fitting a DSP card into it. (They had designed 
      this card as part of a collaboration with Coding Technologies to produce a 
      complete receiver which was also shown at IBC.) 

      The DSP card takes in a low-IF DRM signal and gives out decoded analogue 
      audio. To fit it into the 7030 in the simplest and quickest way possible, 
      a low IF input centred on 12kHz was used, as this was already produced by 
      the tiny downconverter card available as an AOR option. The audio output 
      from the card was then fed to the 7030's own audio amplifier. The card can 
      also provide information like station names, text messages, etc. but these 
      were not used in this quick-and-simple conversion. A separate external 
      power supply fed the DSP card. 

      During the Convention the modified 7030 (together with other DRM 
      receivers) was demonstrated to many interested visitors to the DRM stand, 
      with HF signals received live from DRM-members' transmitters in Canada, 
      Germany, Netherlands Antilles, Portugal and UK. Demonstrating DRM with 
      small receivers like the modified 7030 helped to show that DRM represents 
      an achievable future for broadcasting in the bands below 30MHz.
        
            The modified AOR7030. The BBC DSP card can be seen 
            on the right of the receiver, partly obscured by the loudspeaker. 
            It's a perfect fit! (Picture courtesy BBC R&D).


BBC R&D http://www.bbc.co.uk/rd 
Coding Technologies  http://www.codingtechnologies.com 
Note, the DRM modification provided by AOR does NOT include the DSP board.
Top



KITS & modifications 
AOR will not be producing a KIT for sale, either of the down-converter PCB or 
set of parts.  However, it is VERY LIKELY that the DRM consortium is already 
publishing details for several receivers, see below.

We are aware that a 'generic kit' for the DRM down converter (455kHz - 12kHz) is 
being advertised by a German company Sat-Service:

http://home.t-online.de/home/sat-service/sat/deutsch/produkte.htm  
The DRMRX web site also has a list of modifications. The modification and 
manuals page is at: 
http://www.drmrx.org/receiver_mods.html 
Top



DRMRX - New web site - FRAUNHOFER SOFTWARE DECODER 
A new web site has been set up by DRM consortium members to document 
modifications, provide manuals and the DRM PC demodulating software via FTP 
download.  Distribution is being handled by VT Merlin Communications in the UK. 
A Fraunhofer software package is now available for FTP download, you will need 
to register your details and pay for a licence before the software can be 
downloaded (unique username and password will be provided automatically)... you 
will need a credit card.  The download is around 13MB and a personalised 
activation key is e-mailed to you within 24 hours.  The cost for the licence is 
about 60.00 EURO (approx $60 / 40) and you may select the currency (payment 
handled by WorldPay on-line processing). 
The current software version is V1.0.21 at about 13MB (18 February 2003). 
The site is at http://www.drmrx.org  
The specific software order page is at http://www.drmrx.org/purchase.php  
The following compatibility statement is made on the DRMRX site: 
  Minimum system requirements and soundcard issues, please be aware of the 
  minimum system requirements: 

  Windows 2000 or Windows XP or Windows 98. 
  AT-compatible PC. 
  500 MHz Intel Pentium processor (or equivalent). 800 MHz recommended. 
  64 MB RAM. 
  50 MB free disk space. 
  16-bit SoundBlaster (or compatible) soundcard that supports full duplex at 48 
  kHz sampling rate for input and output; the input must be without AGC 
  (Automatic Gain Control); recommended: Creative SoundBlaster Live! or "USB 
  One" USB Audio Interface 
  LAN network driver or dial-up network installed. 
  Suitable front end with 12 kHz IF output, output level suitable for soundcard. 

  Also, many soundcards are not suitable for use with the DRM software, it may 
  be necessary to purchase an external soundcard (see above and models specified 
  below). 
The modification and manuals page is at http://www.drmrx.org/receiver_mods.html  

Among the equipment modifications are:  AOR AR7030, AKD Target 3, Grundig Yacht 
Boy 400, Icom IC756, Kenwood R1000, JRC NRD525, Yaesu FRG100. 
'DRMRX' also provide a newsletter: 
From: DRM Software Radio News [news@drmrx.org] 
Sent: 06 November 2002 14:41
Subject: New DRM receiver modifcations

Dear All,
VT Merlin have just written up a receiver modification for a AKD Target HF3 
receiver. This is a 
reasonably cheap (180) receiver. 

We found that the phase noise from the 1st Local Oscillator limited the 
performance of the receiver, 
and we suspect this will be a common problem with less expensive receivers. The 
receiver also 
needed careful alignment for optimum performance, so we think it is better to 
start with a more 
expensive receiver that has better performance to start with. The article is 
worth reading, because a 
lot of it is applicable to any receiver. 

The modification document can be downloaded from: 
http://www.drmrx.org/receiver_mods.html 
It is called \"AKD Target HF3\"
The modification for the AOR 7030 has also been added in this area (German only) 


Also, the forum is well and truly underway now, with 70 registrations and as 
many posts. Please 
have a look at http://www.drmrx.org/forum/  Even if you have registered on the 
main site (hence you 
are receiving this e mail), the forum requires a separate registration. 
Regards,
James Briggs
VT Merlin Communications Ltd (Rampisham, Dorset, UK)  
Top
Further comment from VT Merlin Communications, extracted from a recent internet 
positing
www.merlincommunications.com 
I suggest you use the AOR 7030 DRM converted receiver. This receiver is used as 
part of the professional product supplied by FhG and gives excellent results. In 
the future, we may upgrade the software to remote control the receiver. So this 
receiver also has the advantage that it can be remote controlled by the 
software. 

You will also need a 3.5 mm jack to jack connector to connect the AOR and PC 
soundcard. 

For PC's you need a processor speed of at least 500 MHz, 800 MHz recommended. 
The soundcard is important, many will not work. There is more advice on 
soundcards here: 

Not all soundcards work with the software, as some have an automatic AGC that 
cannot be disabled, or they have a low pass filter built in that affects the 
signal. If the internal soundcard does not work, it is necessary to use an 
external soundcard, such as the "USB one". See the software manual for more 
details. http://www.drmrx.org/receiver_mods.html  

The internal soundcards have been tested and work in the following PC's. 
  Dell Inspiron 4100 (laptop)
  Dell Inspiron 8000
  Dell Inspiron 8100
  Dell Latitude 800
  Dell Latitude 810
  Dell Latitude 840
  Sony VAIO PCG-C1MHP, 860MHz/128MB with Yamaha AC-XG soundcard 
  Dell Dimension (desktop) 4100, 800MHz/512MB with Creative SB Audio PCI 64V 
Sometimes you need to disable the AGC or "sound boost" via the settings for the 
soundcard. This depends on the driver you have loaded for the soundcard. 

An external soundcard had to be used with the following PC as the internal one 
was not suitable: 
  Compaq Armada E500
Top



IBOC digital transmission in the USA
IBOC (In-Band-On-Channel) is another form of digital transmission, it can be 
used for narrow band AM and wide band FM applications.  The IBOC consortium is 
called iBiquity http://www.ibiquity.com 
Unlike DRM, IBOC produces both an analogue and digital component so can be 
received on conventional receivers... so theoretically no digital sub-band is 
required.  DRM is not being adopted by the FCC in the USA and countries such as 
Australia appear to have stopped the evaluation of DRM awaiting the results of 
IBOC tests. On the VHF bands, IBOC is planned to replace the Band-II stereo 
service with a similar roll-out to DAB in Europe.  It looks like the video 
standard NTSC/PAL scenario all over again!
IBOC is already on air on the MW band in the USA with WOR in New York City on 
7190kHz already active.  A detailed article relating to WOR and IBOC featured in 
the March 2003 QST Magazine and is recommended reading.
Initial reaction is that the IBOC signals 'SOUND' a lot wider than they should, 
with considerable local spreading of signals wiping out area of the band.  
As there is no PC software demodulator for IBOC at this time, modification or 
implementation of existing receivers is unlikely.  It appears that IBOC 
equipment manufacturers have invested heavily in IBOC and will not easily 
release by-pass technologies.  Perhaps we will see a chip-set with low licence 
at some point, so that the 455kHz IF output of existing equipment can be used 
for IBOC monitoring, only time will tell.
The following web site may be of interest: 
http://members.cox.net/fmdxweb/iboc.html 
The USA based 'Radio World' weekly trade magazine has been following the IBOC 
story closely, their website is http://www.rwonline.com  
Lee Reynolds of the USA has been in contact following the display of his DRM 
modified TenTec RX320 at the SWL show near Philadelphia in March 2003. He posted 
to the IBOC forum to see what experience and views folk had about IBOC... a long 
list of responses followed and are provided here in verbatim... the format is a 
bit messy, but its worth the read - click here
Top



New Zealand DX Times - May 2003
I have been mailed a copy of the New Zealand DX Times and have permission to 
place it on our web site.  It contains interesting information regarding DRM 
(several references), listening reports etc.  The newsletter is in Acrobat PDF 
format, the file is about 1.8MB.  It is suggested that you right-mouse-click the 
link and use the 'save_as' facility to store the file on your PC then open it 
and read it off-line.  Click here to download the file.
The following  copyright is noted:
  The NZ DX Times, PO Box 3011, Auckland.
  Published monthly. Registered publication.
  ISSN 0110-3636.
  Chief Editor/Publisher - Mark Nicholls
  editor@radiodx.com 
  Printed by ProCopy Ltd. Wellington
   All material contained within this magazine is copyright to the New Zealand 
  Radio DX League and may not be used without written permission (which is 
  hereby granted to exchange DX magazines). Where such permission is given, 
  acknowledgement of the NZ DX Times and the original contributor is required.
  NZ DX TimesPO Box 3011, Auckland NEW ZEALAND
Top



DRM bench testing
Some time ago (when DRM transmissions were not a daily occurrence) we devised a 
method of bench testing DRM compatible receivers.  Several commercial 
organisations requested details of how this was achieved.  A two page Acrobat 
PDF file is available with screen shots (136kb) - click here.
Top



Page last updated 12 August 2004 


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