ADF static? question

My friend has an ADF in his C-180 with the type of antenna that goes from the
windshield to the tail.
Says it works fine on the ground during taxi and runup but gets nothing but
static (over the phones and needle won't "track") about 3 to 5 minutes into
flight. Happens every time. There are no static wicks.
Any experience here? Could static buildup be that reliable regardless of the
weather? Any recommendations?

Jim