DAB radio and science

[ronnietucker]

I'm just curious about the science behind this oddity.

In my little Dawncraft 22 (see diagram in my signature) I have a little rechargeable DAB radio (it's standalone and not plugged in when used). If I plug something into a USB port, or turn on a light, the radio cuts out. The other day I used a little fan with a battery bank and the radio still cut out! I thought maybe using the boat USB/lights would block the signal to the radio (cage type thing?) but why did it happen with a battery bank? Even with a different type of DAB radio it still happens.

Answers on a postcard or sealed down envelope to the usual address...  

Edited September 8, 2019 by ronnietucker

[MoominPapa]

USB ports have DC-DC converters which can generate radio interference, similarly some kinds of LED and fluorescent lamps. DC motors have brushes/commutators which spark and generate radio interference.

 

You'd have to be particularly unlucky that all three things generate enough RF at the right frequency to knacker your DAB radio, but it's at least a possibility. The "cliff edge" nature of digital radio doesn't help. It doesn't degrade gracefully, in a fringe reception area it works, or it doesn't.

 

MP.

 

[Chewbacka]

The cheap usb chargers also put rf interference into the supply wiring.  So they can radiate a lot.  The usb charger in my car which is about 10” below the radio prevents reception of all weak fm stations.

[Jen-in-Wellies]

Old fashioned steam radio definitely superior to DAB. Uses a lot less power too. My cheapo FM receiver will run for weeks on a set of rechargable AA's, for several hours a day. As @MoominPapa says, when reception is poor it degrades in a graceful way, rather than just stop working completely.

Jen