DF9CY - DRM Experimental Logfile
Last Revision: 22 March 2004
22 March 2004
I continue receiving DRM with success. I have made some further work on my wideband receiver for DRM.
22 January 2004
My company got interested in DRM now. We purchased a simple crystal controlled receiver, which has remarkably performance. (www.broadcastpartners.nl/drm)
A small review is here:
We ordered the receiver board from Broadcast Partners some days before last Christmas. It arrived now after about four weeks. I have built it into a box and added BNC sockets for antenna, external oscillator, RSSI, 10,7 MHz IF out and AF out. Quality: The pcb is good and no SMD components are used. Components seem to be inserted and soldered manually with good quality. Spec: Supply Voltage: 15V .. 35V, but works from 10V. Currents : 90 mA measured. Bandfilters : (1) 150 kHz .. ca 2 MHz; (2) 5 .. 10 MHz; (3) 13 .. 17 MHz. No (2) is inserted and all other components are within the package. Frequency : I ordered RTL 6095 kHz IF : 10,7 MHz; 455 kHz and 12 kHz ICs : 3 * SA612 mixer; HEF4060 divider; 2 * TL072 OP Oscillators : all with crystals. Sensitivity : -3dBµV for a signal peak of 20 dB above noise at 12 kHz - very good Extensions: I have added an external frequency source input and fed to one of the crystal sockets. I need about 17 dBm for optimum drive. Calculate 10,7 MHz + receive frequency = oscillator frequency (i.e. 10,7 + 6,095 = 16,795 MHz). I used a Rohde 6 Schwarz signal generator for testing, but a good source will be the DDS generator you can buy from www.elv.de or Conrad Elektronik (ca 70 Euro). Performance: The receive performance seem to very good with flat top filtering. Compared to my RX320D it gives me about 1 dB advantage when signal received at the same time from the same antenna. (I have made a so called magic-tee for this purpose). The external signal generator allows me to receive any signal in the given band. The RSSI output makes it easy to put the antenna to an optimum position. Further improvement: I will make a switchable bandfilter which will allow a wider frequency range to operate on. Final: Alltogether we paid 191 Euro for the receiver, as the price claimed excludes VAT and transport. A lot of money. Nevertheless the board works very fine. You cannot receive anything els, as there is no demodulator. BUT using a Software Defined Radio (SDR) like http://www.sdradio.org/ you can receive AM, CW, USB, LSB and FM in excellent quality. I am VERY pleased. (written and published in www.drmrx.org forum) 22 january 2004
16 January 2004
Again some images from some receptions I made recently
|729 kHz DLF with dropouts
||729 kHz DLF over 26 hours
note the nighttime
|1296 kHz BBC World Service
with selective fading
Spectrum Waterfall Display
Receptions made with DReaM 1.0
18 December 2003
I compiled DReaM 1.00. Thanks to the programmers around Volker Fischer for this outstanding software. It seem to run flawlessly.
I also have installed the latest FhG Software Radio 2.0.34, which also is a great work. My first Magnetic Antenna for Medium Wave is ready. The gain seems a little bit high and overdriving my receiver.
September to December 2003
Worked on my DRM Demonstration Receiver which already does work quite well. I changed IF frequency from 30,2 MHz down to 10,7 MHz.
Tried DRM mobile in my car. This was a strange experience. When driving an underpass like a bridge, the dropout came when I had passed that place already by a few seconds. Nevertheless it worked.
I am able to compile the free software DReaM by myself now. I did not get it working on a LINUX based system so far.
There were some more experiments with active antennas, but I could not significantly improve reception over my current antenna (9m Vertical).
31 August 2003
Some images from the software radio:
|177 kHz Longwave
DRM and Analog AM in Simulcast Mode
Offset / No decode
|729 kHz Mediumwave
Offset / No decode
|1296 kHz Mediumwave
Offset / No decode
Here is 729 kHz Deutschlandfunk with DREAM and also decoded sometimes:
DReaM often crashes; it does not seem to be very stable. I have it running under Windows ME.
18 August 2003
Here is a print of the reception log:
Date Time Freq ID Cntry Rpt1 Rpt2 8/4/2003 1438 5975 T-Systems DL 19dB 8/4/2003 1439 6095 RTL LX 18dB 8/4/2003 1441 7320 BBCWS G +15 dB No decoding 8/4/2003 1443 13605 IBB Morocco CN +10dB 15dB QSB 8/4/2003 1445 15780 VoR UA3 12 dB 20 dB 8/9/2003 1452 729 Deutschlandfunk DL 53 No decode, as I have offset of 1 kHz 8/9/2003 1817 6140 DW DL +22dB 8/9/2003 1457 7320 BBCWS G 23dB 8/9/2003 1455 13605 CN 10 dB 8/12/2003 1919 729 DLF Putbus/Rügen DL min 15 dB no decode Offset 8/12/2003 1917 855 DLR Berlin/Berlin DL ca 10 dB Data 8/12/2003 1913 1485 DasDing SWR DL low weak 8/13/2003 1912 531 531 digital DL ca 10 dB no decode 8/13/2003 1910 855 DLR DL peak 12.7 dB 8/13/2003 1858 1485 SWR Das Ding DL 7 dB data decode 8/13/2003 1640 6140 DW DL +20dB qsb 8/13/2003 1641 15780 VoR UA3 18+dB qsb 8/16/2003 1631 6140 DW DL +24 dB 8/17/2003 1035 6140 DW DL 23 db 8/17/2003 1039 7320 BBC WS G 22 db 8/17/2003 1040 9615 RNW NL 9 db 8/17/2003 1041 13755 VoA CN 8/17/2003 1043 15440 DW WS CT1 DL 25 db 8/17/2003 1044 25765 TDF F 10 dB
15 August 2003
My Demonstration Receiver works and I could receive the first DRM signals. A fine success.
30 July 2003
I installed the Software Radio and received the keyfile. It took only minutes to get the thing running. I immediately received the first DRM signals:
|30.07.2003 18.25 UT||6140 kHz||Deutsche Welle||Good Quality but getting weaker due to conditions changing|
|30.07.2003 19.15 UT||9855 kHz||IBB Morocco||Very good signal for more than 1 hour; no drops at all|
28 July 2003
The TenTec RX320D receiver arrived finally after 6 weeks. It works fine.
Middle of July 2003
The plan for the demonstration receiver is made and all parts are here. First stages running.
Middle of June 2003
Made plans for a simple demonstration receiver and ordered the TenTec RX320D
The vertical antenna for reception and amateur radio transmitting is up.
End of May 2003
First impression of DRM in Eindhoven/NL
Text and All Images are Copyright by Christoph Petermann DF9CY
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