Yes, when there is no DAB, the radio switches to FM. The synchronisation is perfect and you only notice it by looking at the display, which shows "FM" instead of DAB. As soon as the DAB signal returns, the unit switches back. This is particularly noticeable at tunnel entrances where the residual FM coverage is stronger than DAB.

On the other hand, switching from FM -> DAB sometimes takes longer (e.g. when leaving a tunnel) and it takes a few seconds (10-15) for the device to recover the signal.

Please note: in French-speaking Switzerland most tunnels are not covered by DAB. So don't be fooled, you won't be able to listen to your favourite programme. The only disappointment is that it is not the fault of the product.

No, this is not possible