In a normal reception area we always use a vertical FM dipole only for
radio, adding it to the system via a 80 to 250MHz filter. There's no
problem with DAB signal strength because the aerial is up on the roof as
opposed to in someone's house (which DAB is designed for) and because the
limiting factor is almost always co-channel signals. If DAB reception is
poor (which normally means the location is officially unserved) we use one
of the European BIII aerial meant for TV. This is because UK DAB aerials
cover channels 5 up and so they are wideband, and have gain of sweet ****
all.

Some time ago you were raving about the Triax DAB 5 element. AFAICR it was
because it wasn't wideband.

I bought one and pointed it due north from my location about 30 miles south
of Sutton Coldfield. It's very good, bringing in about 100 channels (some
duplicates) but also stations from Shropshire and beyond, for which we are
well outside the service area.

The Birmingham stations are all "off the scale" whereas previously on the
internal rod antenna they weren't even being decoded.