[Imported from my older radio programming blog, first published in 06/05/2004]
An unexamined life is not worth living. — Aristotle
I love listening to radio mosly when I’m out of Dhaka. Hmm, where haven’t I gone? Nilphamari*, Bandarban*? Glad you asked. Yes, that’s the beauty of my job … Hell, no! I love my job, cause it allows me reaching out almost all over Bangladesh and beyond and those cool expierences money can’t buy. Wherever I get to, my Sony ICF 7600 makes my day.
I’m still into shortwave listening for some beautiful stations covering our planet … mostly, Radio Netherlands, Deutsche Welle, CBC and BBC! Well, (sigh) I’ve tried those DAB (digital audio broadcasting) and DRM ( Digital Radio Mondiale) in Britain, Frankfurt and Singapore regions. Well, for the techies, you’d say, there is no point falling back and listen to FM radio. The difference between DAB and FM is what would be in AM and FM. I used to listen 3C, Continuous Cool Country, country music station in North East England and JK pop in Singapore (MediaCorp Radio, sg). They did a wonderful job connecting Nashville songs from there.
Software based DRM reciever …
However, DAB tuners are expensive, but if want to know what DAB can be at its best, tune into BBC Radio 3 where you won’t be able to tell the difference between a broadcast and a CD! True, guys!
And for DRM, … not those junk words like windows mediaplayer’s digital right management :-), when one considers that the DRM signal is on shortwave and uses the same radio spectrum as a conventional AM signal, then the results are really impressive. It does whole lot of compression in comparison to DAB (Eureka 147) and still sounds good. I must thank them for making a non-proprietary system for a universal digital system for the AM broadcasting bands below 30 MHz — shortwave, mediumwave and longwave.
It has got a software radio project which will have the radio ready to provide a suitable output to your PC for decoding DRM. Like, if you have a old Sony ICF-7600 series short wave reciever like me, the receiver has a PLL synthesized tuning basis, but largely relies on analog circuitry for AM reception, using double conversion with IF1 = 55.845 MHz and IF2 = 450 kHz. So, you need to integrate the widely used DRM down mixer manufactured by Sat Schneider.
Yes, it is possible to install the DRM mixer circuit, hook up an output jack and install an external antenna connector and that 12 kHz DRM output signal will be hooked to the “line out” jack socket. The original audio output signal will be disconnected, as it is not of much use anyway. The signal is far below specs for “line out”. You will get all the modification instruction in this link. See … what are they saying about shortwave and reaching global? The beauty of shortwave! Period.
The world’s leading international broadcasters are part of DRM, so the early focus will be on HF bands. The great thing about the HF bands is that, potentially, the transmissions can go worldwide. Broadcasters such as BBC World Service, Radio Netherlands, Deutsche Welle, and Radio Canada International/CBC are already making pilot transmissions. National broadcasters will follow on the MF and LF bands.
DRM medium-wave and long-wave test and development networks already exist in Berlin and Halle, Germany and Dorset, UK.We do have the capability to respond to demand, if there is a lot of interest from a particular county, we can put on test transmissions for that country (that’s the beauty of short-wave!)This is why it is useful to us if you register on this site, so we can plan which areas of the world we need to make test transmissions to.
Well, I’ll be back with loads of detail on digital radio transmission pretty soon, specially, DRM on shortwave. Yes, I love shortwave. Until then happy DRMing!
* They are the farthest cities of Bangladesh