Receiving DAB and DAB+

On September 27 in 1995, the public service broadcaster Swedish Radio was first in the world to start DAB - Digital Audio Broadcasting - as a trial and this one hour before BBC started. This timing mistake was because of that local time in Sweden is one hour ahead of England :-)

The Swedish trial became incredible long. The network covered for outdoor reception almost 70 % of the population. After numereous debates and investigations Swedish Radio, after more than 15 (!) years, still has the one and only DAB license. And the coverage is now also heavily limited for several reasons.  Swedish politicians are very very interested in media and they are mostly to blame for this incredible DAB delay compared to other European countries. When satellite tv started they even discussed about prohibiting satellite reception dishes!

In the meantime DAB has evolved into DAB+ giving more programme channel capacity, better audio quality, more suitable for indoor reception etc.. Last year Teracom, the goverrnment owned broadcast networks operator, started a DAB+ trial in the Stockholm area and some other places. A Teracom DAB+ trial report can be downloaded here.

I used to have cars with DAB radios. My car now has an integrated car radio with no DAB. Recently it became possible to buy DAB/DAB+ adaptors here costing less than 125 USD. These adaptors can be connected to a possible low level audio signal input of a car radio, integrated or not. I bought one adaptor made by Argon. The manual can be downloaded here. I live about 30 km from the DAB/DAB+ transmitter site in Stockholm. With the adaptor and a telescoping antenna (not supplied with the adaptor) and connected to my kitchen radio audio input I did compare DAB and DAB+. Receiving DAB was not possible in the kitchen. DAB+ reception was good when adjusting the antenna and moving the adaptor a little for best reception. The DAB+ transmitter has 6 dB more power and the error correction scheme etc. gives another 2 dB gain, which of course is an advantage here for DAB+ trial. I did also compare DAB and DAB+ when driving. The telescoping antenna inside the car did not work so well. With a magnetic mount roof antenna both DAB and DAB+ worked excellent. See video below. Later on I will try to find and use a better car antenna solution for DAB. Some examples are here. I tried an active antenna for DVB-T and DAB for indoor use. The result was better than with the adaptor supplied wire antenna, but still not so good. This ca 1 m long wire antenna has a strange connector not suited for the adaptor antenna F-connector. I think that a home-made Slim Jim antenna made of 300 Ohm Twinlead and hidden behind a window curtain could be a better one. The DAB radio transmissions are normally vertically polarized. DAB is here received on 225.648 MHz (block 12 B) and DAB+ on 229.072 MHz (block 12 D).

This year the Swedish goverment has said it for the first time will issue DAB+ licenses to commercial radio broadcasters. I cross my fingers! Yes we do have commercial radio broadcasters in Sweden, but only since 1993!

Received DAB and DAB+ programmes in Jordbro,
QTH locator JO99bd:


Lennart J said…
Thanks a lot for an excellent survey of the evolution of the DAB standard combined with field trials.
Can you estimate the impovement of efficieny of DAB+ compared with "the old DAB"? How many more channels can be transmitted given the same power, bandwidth and sound quality?

Do you have except for UK any new information of what happens in the major countries of Europe concerning DAB?

Regards/Lennart J
Mni tnx fer ur interest in this Lennart!

One DAB+ mux can host 10-16 programmes with MP4 coding compared to 6-10 programmes with MP2 in a DAB mux. DAB+ is 2-3 dB more robust and there is no annoying bubble sound near the treshold level and hence better suited and cost effective for indoor reception. More info is available via links above.

A fresh country update can be downloaded here:

Swedish neighbour Denmark has 95 % indoor coverage and 1.5 million receivers are sold up to now. Norway has 80 % coverage and 0.3 million receivers sold. Finland switched off DAB in 2005 because of little interest from the consumers and maybe also because of Nokia´s heavy involvement with DVB-H.