W124 Power Aerial with Modern DAB Head Unit?

[Placid Casual]

I'd like to fit a DAB into my 260E, but retain the power aerial for FM use.
I realise that I'll have to fit either a splitter or an additional DAB aerial, but modern head units don't seem to have an output signal to power the electric aerial.

I guess I could use a feed from the ignition and just switch it with that, but has anyone got any better ideas?

 

[richard]

They do have an output to turn on an amplifier - use that instead

Richard