27 and 40 MHz aerial are just a single wire. A few 2G4 aerials are as well, and can be recognised by only being about 30mm long. Both these cases, the entire wire is the aerial.
Most 2G4 aerial wire are a length of coax cable with the end 30mm having the shield removed. The rest of it is there to let you place the radio where you would prefer it, and at the same time, the useful bit of the aerial where you need it. The outer sheath is normally connected to the receivers ground plane.
I've not had one, so am relying on hearsay, but I read that the T5 is not a "full range" radio. This might well involve the receiver aerial being just a simple length of wire 30-something mm long.