His idea was to use the tape as the radiator for an end-fed halfwave, or EFHW, antenna, a multiband design that’s a popular option for hams operating from the 80-m band down to the 10-m band.

The video shows the inside of the box which, as you’d expect, is a toroid with a few turns of wire. The proposed antenna is an end-fed dipole fed with the unun. These are somewhat controversial ...