DAB vs AM/FM
Lots of places need the "Whip" up for FM. The AM is convenient and gives coverage to small number of places not reached by AM.
1) Old AM Valve Portable Radio using replicated battery packs: 60 to 400 hours and 6p to 12p per hour depending on model. The 1953 to 1960 models only used 25mA @ 1.4V per filament and 6.5mA to 9mA HT depending on model
2) Decent 1965 to 2000+ AM/FM portable transistor or IC set: 60 to 250 hours and typically 1p to 8p per hour depending on Model and loudness.
3) DAB sets : 4 hours (4 x AA some current models) to allegedly 120 (latest Roberts using expensive Alkaline D cells) 5p to 75p per hour. (Lower price assuming cheap supermarket Alkaline, not Energizer/Duracell/Panasonic and Roberts are truthful about consumption).