digital radio?

Discussion in 'General Electronics Chat' started by Mathematics!, Jan 27, 2010.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    I am curious about a few radio questions.

    One , is you can buy digital radio's but what are the difference between these and the normal radio's that interpert analog radio waves.

    Are they just transforming the analog to digital --- then to a DSP for minupulation --- then back to analog to the speaker/amiplifier.

    Question 2

    Some of these radio's are said to be HD (high definition)
    But how can you make audio any more high definition then it orignially is besides the fact of reducing noise. I have even heard radio stations saying they broadcast in HD, but I don't understand how you can improve on voice quality other then the fact of filtering more noise out. If you are able to use all the 20hz to 20khz range that is all we can here it is not like TV broadcast where more pixel data can be transmitted ...etc to make better quality , is just audio...

    Do any radio stations broadcast digitally or is this just the cable companies TV broadcasts that are switching to all digital QAM64 ,...etc

    Will the radio stations in the near future ever switch to all digital?
    I guess the reason why the TV stations switched is because less bandwidth a channel takes up along with being able to encrypt/decrypt a channel easier , less interference ,....etc

    Thanks for your comments
  2. JDT

    Well-Known Member

    Feb 12, 2009
    In the UK, and many other countries, radio is now transmitted digitally - so there is a difference.

    The signal is a MP2 stream at 128kb/s or less, so the quality is generally worse than a good analog FM signal.

    Advantages: A number of stations can be multiplexed increasing the number of stations that can occupy a certain bandwidth.

    In the UK, we are told that eventually the FM radio transmissions will be closed down allowing the government to sell off this spectrum to other users. There is much protest over this.

    An alternative technology is DAB+ which uses a more advanced codec that might give better quality. Some countries are adopting this.

    For more information see:-

    You can also now get portable Wi-Fi internet radios for listening to internet radio.

    Most of these radios can also receive standard FM.
  3. vanyablue

    New Member

    Jan 28, 2010

    HD is not, and is not supposed to be “High Definition”.
    It’s a means of piggy-backing a digital signal onto an existing analogue AM of FM radio signal. The quality is dependent on the bitrate used.
    See this:-
    When most people first hear of HD Radio, they often assume it's like HDTV, but for radio. HD Radio is a very different technology, however. Unlike the "HD" in HDTV, the "HD" in HD Radio is not an abbreviation for "High Definition." Although some have said that it actually means "Hybrid Digital," according to iBiquity, "HD" is a trademarked brand name and doesn't actually stand for anything [Source: Crutchfield Advisor].
    Cheers, Ian.
  4. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    wow , I didn't know everything is moving to digital even the radio stations.
    If this is true their is going to be alot of unhappy people when radio goes all digital think of how many radios will by worth less....

    Unless of course digital to analog converters become more popular for a while ... to wien people of the analog and to upgrade to digital....

    Wow didn't know that so if I was to drive me car in the UK I couldn't listen to the radio without a digital to analog converter box for my car radio.... that sucks! but it the long run it will be better but for the transistion it sucks.....

    Is their anything that really needs analog or could everything be eventually done better thru digital...?
    Seems to me anything you can do with analog can be done with digital and with less bandwidth , more manipuation over the signal , more encryption , compression ,...etc

    Does anybody know if the US is going to switch their radio stations to broadcast in all digital anytime soon??? Like the proposel for TV brodcasting.
  5. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    Although analog TV is starting a phased shutdown in the UK, analog (FM) radio is likely to be here for some years.

    The existing digital 'DAB' system is sadly nothing like as good as it was supposed to be. In many areas that are supposed to have full coverage, reception indoors is poor to none-existent.

    I believe the problem is that the digital format is far more sensitive to multipath distortion and weak signals than analog FM.
  6. bertus


    Apr 5, 2008