With most AM stations, the tower itself is the radiator. That&#x27;s the reason for the insulation from ground. If the tower were grounded, it would not be able to transmit a signal at all. In the video, while that cable is attached, the tower cannot transmit.<p>I wasn&#x27;t sure about the device they were shorting so I asked the chief engineer for several large radio stations in the area.<p>That device is a lighting transformer [1][2] -- it allows AC power to be coupled to the tower, to power the lights, without a direct connection, which would severely impact the tower&#x27;s ability to radiate RF energy. The two little balls is called a lightning gap, it gives lightning a path to ground, other than the connection to the transmitter, since the tower itself is not grounded.<p>[1] <a href="http:&#x2F;&#x2F;www.austin-insulators.com&#x2F;radio&#x2F;xfmr.html" rel="nofollow">http:&#x2F;&#x2F;www.austin-insulators.com&#x2F;radio&#x2F;xfmr.html</a><p>[2] <a href="http:&#x2F;&#x2F;www.sonifex.com.au&#x2F;?media_dl=3300" rel="nofollow">http:&#x2F;&#x2F;www.sonifex.com.au&#x2F;?media_dl=3300</a> (PDF)