External antenna for DAB radio?

[blackrose]

Can anyone recommend a good external antenna for a DAB radio? Preferably I'm looking for something small, perhaps a car antenna which doesn't need it's own power supply, which would be easy to fit.

 

(Edit: Apologies, I thought I'd posted this under "Equipment")

Edited December 27, 2007 by blackrose

[chris w]

Can anyone recommend a good external antenna for a DAB radio? Preferably I'm looking for something small, perhaps a car antenna which doesn't need it's own power supply, which would be easy to fit.

 

(Edit: Apologies, I thought I'd posted this under "Equipment")

 

A car antenna would do but cut its length in half as DAB is about twice the frequency of FM. You could try trimming it bit by bit for maximum smoke (techy talk for best signal).

 

Chris

[bottle]

Hi

 

Have a google for "dab car aerial" include the quotes, from a quick perusal it looks like Chris's advice is correct.

 

The length to cut it to varies between 40 and 30 cms, so I would start at the longer length and trim about a 1cm each time.

[blackrose]

Thanks.

 

Maplins doesn't seem to have a lot under Magnetic Mounted Antenna, which is the sort of thing I'm looking for.

 

http://www.maplin.co.uk/searchtemplate.asp...MOUNT%20ANTENNA

[chris w]

Thanks.

 

Maplins doesn't seem to have a lot under Magnetic Mounted Antenna, which is the sort of thing I'm looking for.

 

http://www.maplin.co.uk/searchtemplate.asp...MOUNT%20ANTENNA

 

 

Mike

 

This Maplin's one here will do the trick. Although its length is stated as 75cm, that's its physical length. Its electrical length will be around 300cm (quarter wavelength @ CB frequency of 27MHz) due to the bulgy thing in the middle (it's a coil).

 

The aerial is simply a vertical wire covered in plastic with the coil in the middle. If you scrape the plastic coating off, above and below the coil and simply solder a length of wire across the coil (to short it out) you will have the perfect length DAB aerial. (75cm = half wavelength @ 200MHz)

 

You'll also need to change the plug to suit your DAB radio. At only £14.99 it's got to be worth a punt.

 

Chris

Edited December 28, 2007 by chris w

[blackrose]

Thanks Chris

[NB Alnwick]

Can anyone recommend a good external antenna for a DAB radio? Preferably I'm looking for something small, perhaps a car antenna which doesn't need it's own power supply, which would be easy to fit.

 

We asked the same question about a year ago and didn't get a satisfactory answer so we contacted Peter Longhurst who manufactures equipment for Amateur Radio enthusiasts. Here is a copy of his answer:

 

Thank you for your enquiry; I hope to give you a grain

of reassurance by mentioning I have several hundred

hours experience crewing a 54' NB.

 

If you use one of our standard magnetic bases (type

501) which comes with up to 5m of moulded in co-ax

cable, to which we can fit pretty well any plug on

request.

It offers a 3/8" UNF socket mount for the aerial whip,

this is an industry standard.

 

You can then readily exchange different whips for your

various applications, the whips being fitted with the

3/8" screw fitting.

This fitting takes two forms: a straight non-folding

and a hinged, which should better take care of

low-flying bridges and trees. The Band 2 FM whip is

about 0.75m long, the DAB about half that.

 

I can cut whips for the required frequency band, which

includes all of your requirements including marine

sometime in the future.

 

Have a look at the mag mount and aerial whip pages in

my website and I will be pleased to provide a

customised quote, and any further advice which you may

require.

 

http://garex.co.uk/aerials/aerials.htm

 

In the end we settled for a Band 2 FM whip and the magnetic base - which works surprisingly well with both FM and DAB - and we can certainly recommend Peter's company 'Garex' for such items.

[Keeping Up]

An amateur radio 2-metre band antenna works superbly as a VHF marine radio aerial, for transmitting and receiving, if you cut about an inch and a half off the end. You can then mount it using your favourite amateur base, be it magnetic or whatever. If you don't need to use your DAB radio when you're using the VHF marine radio, you only need to have one such base for the two radios!

[tangysheep]

Greetings

I've fitted one of the short flexie rubber car ariels from our local car spares shop on the cratch board above the tunnel light.

The cable runs down the board and through the side locker and then through the front bulkhead into a corner cupboard on which the Dab radio sits.

It works great. The radio was from Lidl with a 12volt transformer so it's wired into the 12 volt system.

Regards

Steve

[chris w]

Aerials are a bit of a black art still and although the rubber car aerial types in theory should be bad at DAB frequencies, it all depends on the signal strength. Such an aerial is about an 1/8th wavelength at DAB frequencies and, so long as the signal strength is high, will suffice.

 

It's only in marginal areas of signal strength that one needs to get the optimum DAB aerial length.

 

Chris

[blackrose]

http://garex.co.uk/aerials/aerials.htm

 

In the end we settled for a Band 2 FM whip and the magnetic base - which works surprisingly well with both FM and DAB - and we can certainly recommend Peter's company 'Garex' for such items.

 

Thanks, I'm not quite sure what you mean by Band 2 FM whip - I can't see that one on the website?

Edited December 30, 2007 by blackrose

[NB Alnwick]

Thanks, I'm not quite sure what you mean by Band 2 FM whip - I can't see that one on the website?

 

The magnetic base is on the website - the whip was purpose made for us - it all works fine and the mag base doesn't damage the paint up top . . .

[blackrose]

The magnetic base is on the website - the whip was purpose made for us - it all works fine and the mag base doesn't damage the paint up top . . .

 

Cheers I'll give them a call