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Being able to decode RDS data is really an ideal aid for FMDXing, perhaps as interesting as the change from analogue to digital readout. Additional information can be obtained in this way and you know with far more certainty which station you are listening to: it's right there on your display! Sounds great, but still signals can be too weak or your decoder can be too insensitive to show you all the RDS data you were hoping to see on your display. Separate decoders as well as built-in ones show this deficiency: signals must be pretty strong to appear on the display. Moreover, separate decoders like the Conrad RDS Manager can't retain the data: signal gone, data gone! One has to be alert and make some notes. Fortunately RDS tuners can store the RDS data in a temporary memory, but these tuners aren't often as sensitive in decoding RDS as one would like them to be.
These problems can, however, be solved thanks to your computer: there is a lot of RDS software around to enhance the performance of your decoder. You can of course install this software and see what it looks like; some of these programs contain some samples,giving you an idea what the real stuff looks like. If you decide this is the way to go, you will have to find out about the DATA and the CLOCK signal in the decoder: that's what your PC needs to feed the software.
If you study your manual and know something about electronics, you could open up your tuner and start working on it. Perhaps you might want to build your own decoder.
You can check out the Puskas Barnabas decoder or have a look at the one built by Carsten Groß

Not being a technician myself I guess I wouldn't like operating on my expensive tuner myself. There are some alternatives, however: the Conrad RDS Manager (CRM) and the GNS Radiocard. Let's have a look at the Conrad RDS Manager first. The CRM can be easily modified at Conradalmost no cost and taking up only 30 minutes of your time. The results will be stunning! Details on where and how to obtain the CRM can be found at the end of this article.
How to modify the CRM? What you need is this: a piece of wire (2 'cores' and 1 earth), 1 bi-polar capacitor of >1µF, 1 bi-polar capacitor of >4.7µF and a SUD-D plug (9 or 25 pins). The values of the capacitors are NOT critical, I used 4 and 10 µF. They are just a protection between the RDS IC and the computer.
A Philips SAA6579 chip is used in the Conrad.
In some tuners the Philips SAA6588 chip is found.
Puskas Barnabas uses the TDA7330 chip to build his RDS decoder

RDS IC Inside the CRM you will find 2 resistors near the RDS IC. R6 is for CLOCK and R4 is for DATA! R6 and R4 Inside the little box you can make an earth connection at the end where the cables enter (from tuner to CRM and the power cable). There is a small metallic covering which can be used as earth.
How to connect? The >1µF is soldered to CLOCK(R6) and the >4.7µF to DATA(R4). The other 'leg' of the capacitor is soldered to the SUB-D, via your cable of course. Make sure you solder this on the top of the circuit board (where you CAN'T see the RDS chip) and on the left-hand side of R6 and R4 and to the right-hand side of C11 (a disc shaped capacitor). (Seen with the display turned towards you).
How? CLOCK is soldered to pin 8(5), DATA to pin 6(6) and 'earth' to pin 5(7). If you want to use RDSDecoder 2.01 mind the different connection! CLOCK is soldered to pin 9(22) and DATA to pin 6(6). If you want to run the DOS software (i.e. if your computer doesn't run too fast) AND the RDSDecoder, connect Clock to Pin 8 AND 9 (5 AND 22). The first pin number is for 9 pins SUB-Ds and the second for 25 pins SUB-Ds!
That's all there is to. It will cost you half an hour of soldering time and just a few Euros to buy the wire, capacitors and SUB-D.
More modifications! If you think the modification mentioned above it a bit overdone as you feel you have no need for software RDS decoding, just giving the CRM PI codes decoding capabilities will be sufficient, there's a great modification to the CRM around. Have a look at Jan Kolar's website! You can even combine the 2 modifications in 1 CRM!
Having modified your CRM or your tuner you can now connect it to your PC and run the software. In the next part of this article 4 RDS programs will be discussed. They are all in use by FMDXers from the Benelux, Germany, UK and USA. All but one of these programs are DOS programs. You won't need a deluxe computer to run the DOS software. An old 386 -and even a 286 as the makers claim- will do nicely. You can also run them in a Window if you prefer Win95/98. Let's have a closer look.
1. RDSDecoder 2.01 from Esslinger RDSDecoder 3.0 from Esslinger
Unlike the other decoding software mentioned below the RDSDecoder 2.01 is a Windows(Win95/98/Me) based program and it runs nicely. Be careful with the .vxd. My pc wouldn't boot when the CRM was still on (synching to COM1). Apparently Win98 has a problem with the driver. However once booted (so fire up the CRM after booting) it runs very smoothly. The free demo version does not support logfiles or recording/playing samples. Of course you can see PS/PI/AF/EON/Groups/ Bit Error statics and more. At this very moment the price of a full version is unclear. This RDSDecoder 2.01 is a good alternative if your fast pc doesn't run DOS software reviewed below. This program must be downloaded directly from Esslinger (Thanks to Bill Nollman for providing this information. You might want to visit his interesting RDS website!)

flash WARNING! flash
Some of the software mentioned below WILL NOT work on a fast computer, 
say a PentiumII 300MHz or better. 
You will see a runtime error on your computer screen.
A few programs have been patched and do run on a 1.33GHZ!
The patch to unlock programs written in TurboPascal, producing 
the runtime error 200 can be found here.
2. RDS.EXE from UKW/TV Arbeidskreis.
This really tiny programme (46 KB) uses just 2 simple black and white screens. These screens give you already far more information than your (separate) decoder. Of course the PI code is shown, but also PS/AF/PTY/TP/TA/EON etc. are there. It's all in German but due to its simplicity that won't pose problems for non German speakers. Information can be logged in a file (ASCII), but you'll have to leave to programme to view it. A bit clumsy perhaps. You can also change certain 'preferences' such as the rate of a failure in decoding. A high rate will mean quick decoding but with a margin of error. A low rate will mean slower decoding but 100% correct. It's up to you to find out what's best. Some drawbacks in the RDS.EXE are its slow way in detecting data, albeit still a bit faster than ordinary decoders, and its lack of a sampling mode: you cannot record data and play it back as if it were 'live' on your screen. Such a sampling mode can be interesting if you want to study the RDS data after a DX session. Conclusion: RDS.EXE is a simple and practical program that works perfectly, what you see is what you get .
3. RRDS from Christoph Lorenz.
Again a very small program: it won't need more than 200 KB on your harddisk. Very striking are the big 'windows' used on the screen. The PS window takes up half your screen! Huge letters on a simple background. Ideal for the visually impaired. RRDS also gives you all the RDS information you might need, even In House Data and Raw Data can be seen and all of this using English terminology. Moreover it's the only software discussed in this article that allows you to use the mouse to open and close windows. A log file is automatically generated (with good quality signals) or can be forced. In RRDS you can make samples, which means you can view your recordings the way they first appeared on the screen and check out things like EON, AF etc. The software is pretty fast in decoding data and just like the RDS.EXE it's possible to set your preferences. Alas, one big drawback casts a shadow on this software: RRDS tends to crash every now and then! Nerve-racking in the middle of a DX session. The author, Christoph Lorenz, knows about the problem but hasn't got the time or interest to fix it. Conclusion: RRDS is a fine program, it's quick and has clear graphics, but the bug in it is a real pity.
4. RDSS0375 from Martin Schultz.
Just like RDS.EXE and RRDS this sofware is of German origin. All the screen info is in German only. The programme needs some 400KB of free space on your disk, again not a lot. If you are new to RDS decoding this RDSS0375 will certainly take your breath away: more than 20 screens filled with data and lots of colours which all have a specific meaning! The startscreen will tell you were you can find the info you need, although from personal experience I can say screen 23 (F8F4) is the best one: all relevant data can be read from this screen. Martin Schultz really intended to make this a professional program: you can decode PI/PS/PTY/TA/TP/MS/IH/RT/DI/EON and more. It's possible to see how the data is binary structured or how the different data groups are sequenced. You might be overwhelmed at first by all this information, but a readme.file is provided. Unfortunately it's in German only. There's a small user guide to this program on this website. Click here. RDDS0375 is my favourite of the software mentioned in this text: it's really quick in decoding, even a failure rate of 98% will give you a PI code, which can help you in identifying the station. It's also possible to record and play samples and that can be done in a very easy manner. In the later version of the programme (RDSS0389) 3 decoders are used in 1 screen: a slow one with high accuracy and a quick one which is more prone to displaying 'phantom' PIs. In the RDSS0389 you can label your samples and logbooks are automatically generated: one for the slow decoder (.txt) and one for the fast (.log). A new screen (F8F4F7) shows how PI codes are generated and how the correct ones are marked. Highly recommended! A few lines from a recent Es opening as shown in the log file of my RDSS0389:
| Datum | Zeit | PI | PS |11.07.1999|17:03:52|99FF| KTIS : |*| 8|1|0|M| 2|000020|11.07.1999|17:04:21| |11.07.1999|17:05:37|1464| SKAI |*| 1|1|0|S| 1|00000B|11.07.1999|17:05:39| |11.07.1999|17:07:40|5000| TEL. |*| 0|0|0|M| 0|000007|11.07.1999|17:07:44| |11.07.1999|17:12:49|100A| 94,T FM|*| 4|1|0|S| 1|00000E|11.07.1999|17:12:52| |11.07.1999|17:19:32|5400| LISTEN |*|15|1|1|M| 1|00000A|11.07.1999|17:19:34| |11.07.1999|17:29:21|FFFF|VENUS 91|*| 0|1|0|M| 9|00000E|11.07.1999|17:29:24| |11.07.1999|17:39:27|5158|Manbassa|*| 9|1|0|M| 5|000020|11.07.1999|17:39:39| |11.07.1999|18:52:34|5201|RAI MF1 |*| 0|1|0|M| 1|00001D|11.07.1999|18:52:58| |11.07.1999|19:07:52|5274|FANT..CA|*| 0|1|0|M| 1|000052|11.07.1999|19:10:32| |11.07.1999|19:17:33|5057|R.ELLE |*| 0|1|0|M| 1|000028|11.07.1999|19:17:34| |11.07.1999|19:35:03|5021| R.S.I.|*| 9|0|0|S| 5|000033|11.07.1999|19:35:19| |11.07.1999|19:42:46|5443|GALAXIAS|*| 0|0|0|M| 0|000008|11.07.1999|19:42:46| It's not possible to set your own preferences but be assured that the author has set all the parameters perfectly. Conclusion: RDSS0360, 0375, 0385, 0388 and 0389 is a fine DX instrument. Its performance is truly outstanding and it provides the user with a wealth of RDS info. To my liking this is the best there is!
Where to obtain these RDS programs?
They can be downloaded from the Internet from Martin's website or look below.
Or write to Martin Schultz: An der Vossbergen 26B, D-26133 Oldenburg Germany !!It's recommended to register the RDSS0375 as Martin will then certainly provide you with the updated versions!! Also a registered copy performs better in recording samples than an unregisterd copy. Newer versions of the program can only be obtained from Martin directly.

Where to obtain the Conrad RDS Manager?
Unfortunately Conrad no longer sell the Conrad RDS Manager! You might contact FMDxers or search the net to find the famous CRM. This is what Conrad said about the RDS Manager:
This unit represents a most useful addition to your hi-fi system and, above all, makes it easier to identify unknown stations that you have tuned into. Inadvertent allocation of two stations to one memory is now a thing of the past. Connection is via an LF output on the tuner or amplifier. If a station you have tuned into is transmitting RDS information, its name will immediately appear on the illuminated display, e.g. Radio 2. A six-part bar chart display provides you with information about the quality of the RDS signal. At the touch of a button, you can switch to further RDS information. If a radiotext is received, this runs through on the display until you switch to another function. In the Time mode, the precise DCF time is displayed as long as the station is transmitting a time signal. Some stations are already transmitting a PTY signal which includes the programme type. This appears on the display, e.g. (»NEWS«, »CLASSICS«, »SPORT« etc.). Another button allows you to select alternative frequencies on which this station is transmitted so you can find the one with the best reception. Specifications: Operating voltage 12 V= (9 - 16 V) · Power consumption approx. 85 mA · Input sensitivity approx. 0.6 mV - 1 V · Input resistance 25 kW. Phono-adaptor (T-shaped) included. · Dimensions (W x D x H) 110 x 80 x 37 mm. Order No. 314005-

The GNS Radiocard GNS Radiocard, also sold as Lifestyle Software PCMCIA Radiocard DR2001. www.gns-gmbh.com and www.tmcdecoder.de Price: € 256,- including software. Optional window clip antenna: € 25,-. Shipping and handling: € 7,- in Germany, € 16,- in Europe, € 22,- outside Europe.
The GNS Radiocard is a miniature radio on a standard PC Card. The RadioCard The Radiocard has two connectors: one cinch to connect the optional external window clip antenna and one 3.5" jack to connect to the line in of your PC's soundcard or an external amplifier. This output is line level, so the signal is too weak for a pair of headphones. The card is controlled entirely by software on your PC. The following software is supplied with the card:
  • Lifestyle Radio: the radio control software.
  • TMC Decoder: an application to read and display
TMC Software Traffic Message Channel information,provided this information is transmitted in your country. This package is marketed primarily as a mobile TMC application. In this review however, we'll concentrate on its capabilities as an FM radio and RDS decoder.
Software installation
Both Lifestyle Radio and TMC Decoder are Windows applications, provided on a CD-ROM. Our tests were performed on a Windows 2000 equipped laptop. The only problem we've encountered is that we needed to change the COM port to 4 (the default is 2). Otherwise, installation went without a glitch. No software or drivers are provided for alternative operating systems, such as MacOS or Linux.
The Lifestyle Radio software
Lifestyle Radio Software When the software is run, only a small window is displayed. It offers the following information and functions: 1. PS code of the selected station (Programme name). 2. Radiotext. By pushing button 9, you can toggle between Radiotext, PTY, PI, CT and Radiotext. 3. Selected frequency. You can tune into a frequency directly by entering the 4 or 5 digits (e.g. 9450 or 10280 for 94.5 MHz and 102.8 MHz respectively) 4. Selected preset. You can store up to 10 stations in presets. 5. Received RDS codes. From left to right: TMC, TP, TA, EON, music/speech, CT, AF, DGPS 6. Power button. Exits the application. 7. Volume slider. Adjusts the playback volume only when playing through the PC's soundcard. Doesn't function when the card is connected to an external amplifier. 8. Station selection. Selects presets 0 to 9. 9. Display. Toggles between the display modes described under 2. 10.Tuning. Manual tuning in 0.05 MHz steps. Auto-tuning when you keep the button pressed a bit longer. 11.Mute. Mutes the volume (only if playing back sound through the PC's soundcard). 12.Set-up. Access to the following advanced functions: GNS Set-up INFO: displays the software's info dialogue box AUTO TMC: Choosing this function will start an auto-search for a TMC broadcast station. If you should leave the broadcast area of a TMC-station, then a new station will be searched for automatically. We did not test this feature. RT SLOW: allows you to toggle between fast and slow RT display. SAVE RT: when clicked, all RT information is stored in an RT.TXT file. STORE: stores the current frequency to the currently selected preset. We found this particularly irritating, because you first need to select the preset, then tune in to the frequency and then store it. We would have preferred to tune in first, then click store and then select the preset to which you want to store the frequency. SETTINGS: allows you to select the COM port, TMC software and file name for the RT file. AF: displays the AF list for the station you're tuned into. SEARCH: starts the search function, which stores all received stations in the station list (not the same as the presets). STOP: stops the search function. Station list: list containing the found stations with their frequency and PS.
Test results
The Radiocard seems particularly fragile. In our sample, the antenna connector came loose when detaching the external antenna. Also the line out seemed to provide a "fluctuating" signal, which sometimes seemed to disappear altogether and then came back when moving the cable a little bit. The sound quality was average at best. It is not clear if this is due to the Radiocard's sound circuitry or to the bad connection. As far as sensitivity and selectivity are concerned, the Radiocard's performance was utterly disappointing. Our tests were performed in Ghent (B). There are some strong local signals (commercial stations). The main transmitter for he Public Radio VRT is 50 kW for each channel at a distance of approximately 30 km. At our test location, we are able to receive approximately 45 channels with RDS identification on a cheap (€ 125) all-in-one sound system, with the built-in aerial. The Radiocard only received 6 (!) strong local signals in auto-tune mode. When tuning manually, we were able to hear some 12 stations, but only 8 of them had an RDS identification. The main VRT stations are too weak to be identified. Very often, the PS and RT contained garbled or missing characters. Even the PI is not always accurate. As an extreme example: Studio Brussel, transmitting with 500 W ERP at 600 m from our test location is not always received correctly. We were unable to tune into a signal strong enough to fill the AF list.
For the FM DX enthusiast, the GNS Radiocard is a good idea badly executed. Performance is weak and, considering the price, we expected the card to be more sturdy. On the positive side, the software does what it promises to do, and the Radiocard offers an ultra-compact solution for people who travel a lot with their notebook PC. So if you want to explore the local FM band in cities you visit, this may be an interesting solution. Otherwise, invest your money in a good tuner and aerial, and use some freeware RDS application. (The GNS RadioCard part of this webpage was written by Pieter De Windt from Ghent. Please have a look at his interesting radio webpage! RDS Software Decoder Bernd P from Germany offer the freeware RDS Decoder on his homepage. This program can be used with the TerraTec ActiveRadio FM tuner RDS
Why bother using this RDS software after all?
Besides giving you all the extra information and being a lot quicker than the ordinary decoders (they often tell you 'NO RDS' while your PC's screen is filled with data!), there is more. What about sending a reception report to a station with a screen dump of their RDS signal? I already received some enthusiastic comments from stations I've sent such a report to. Or what about exchanging samples you've made with other users of RDS software? It's really great fun to exchange samples with people from other countries via email.
If you still have some unanswered questions, feel free to contact me.
© Herman Wijnants


Download RDS20  Unpatchedzipfile

Download RRDSzipfile

Download RRDS Runs on fast cpuzipfile

Download RDSS0375  Patchedzipfile

Download RDSS0385 Patchedzipfile

Download RDSS0388 Unpatchedzipfile

Download RDSS0389 Unpatchedzipfile

Download RDSDecoder 2.01 from Esllinger WindowsWin95/98/Me

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