Stupid Question

[Islay]

Is DAB and digital FM the same thing?

[EcclesCake]

As DAB stands for Digital Audio Broadcast I would say yes.

[Kidas]

No. FM = frequency modulation. The only digital thing about it is the tunig system. That is fixed digitally, but the signal is analogue.

DAB is a fully-digital system - like all UK terrestrial TV nowadays. It needs a digital receiver to decode the signal

[cupid04]

a dab is a fish, the other is a radio frequency.

[EcclesCake]

Kidas, so how do I receive FM stations in my car?

[Kidas]

Most DAB radios also have an FM tuner.

You can get 20-ish stations in the FM frequency band that runs from about 88MHz up to about 108MHz (from memory), because each station needs a different frequency and side bands, so each station takes up a specific range of frequencies.

DAB is fully digital, so multiple stations can be carried on the same carrier frequency as a multiplex. Ths means you can carry many more stations on the DAB system.

In practice, this means (nearly) all the stations available on FM are also available on DAB, but DAB can carry many more stations.

[Kidas]

Oh, and DAB radios operate on frequencies about 220MHz to 230MHz, so different frequency ranges as well.

[Buenchico]

A 'digital FM' receiver simply has a digital display (or possibly incorporates a 'PLL' tuning circuit) but it doesn't receive DAB transmissions.

[Islay]

Thanks all - will have to return the gift I got hubby for VD as he wanted a DAB alarm clock and I got the wrong thing!!

[Buenchico]

Sainsbury's sell a good one for £30:
https://www.sainsburys.co.uk/shop/gb/groceries/radio---speakers-281906-44/blaupunkt-dab--fm-digital-alarm-clock-radio-131256815-p-44

If you're quick, you can buy one from your nearest branch before the day is over ;-)

[Kidas]

Islay

Good decision.

Things to look out for when buying a DAB bedside radio/alarm clock:

1. brightness of the display. If you like things dark at night, check that you can dim the display right down. We've tried a series of different types and display brightness can be an issue.

2. If you like to go to sleep listening to one station, you'll need a sleep timer function. If you want to wake up to a different station, then check the radio will do that.

3. Again, if you want to go to sleep using the timer, check whether the volume is sufficiently adjustable. Most volume controls work in discrete steps, and the difference between completely quiet and minimum volume may be too great.

4. Will the radio switch itself off once it has done its job and woken you up, or do you have to switch it off manually?

We now have more than 10 DAB radios kicking around the house. Definitely better than FM, but be aware that DAB introduces a second or two delay, so you can't really have one FM radio and a second DAB radio in the same room, even if they are tuned to the same station.

[Islay]

Thanks returned and have ordered another which will be here tomorrow or Friday.
Thank you for all your help

[sunny-dave]

There's nothing inherently wrong with DAB - but (like FM) it's at the mercy of the broadcaster as to the technical quality of what is transmitted.

Radio 3 and 4 sound fine - high bit-rate and no compression - the FM for these stations is good too.

Radio 2 is not so good and Radio 1 (and BBC Local and most Commercial stations) sound absolutely appalling - they've let idiots 'turn up the wick' so that they are 'the loudest on the dial' - with the resulting compression removing all nuances and quality from both the voices and the music.

There was a chance to do things properly - but Ofcom (as usual) were about as useful as a chocolate fireguard - probably because they didn't even understand the problem until it was too late.

I despair of the technological ineptitude of the 'great and good' running these bodies - having a PhD in Greek Studies (other useless qualifications are available) is no preparation for policing a 21st century technological infrastructure.