This clip is cited within the discussion about how ground proximity affects antenna patterns in Chapter 2.
At 03:00 in the recording, VK2UXO reports the verticals are perhaps 5 dB louder than the 4-element yagi.
At 10:40 in the recording, VK3CM reports the verticals are 15 dB louder.
Whereas VK2UXO & W2VP report QSB in their reception reports using horizontal antennas, reception of their signals off the verticals has no QSB. Nulls in horizontal elevation plots is covered in Chapter 2.
The 4-element yagi featured in the recording appeared on the front cover of QST (June, 2019).
Learn more about how ground proximity sculpts antenna patterns in Chapter 2 of Saltwater Verticals & Phased Arrays.
Vertical vs Horizontal Shootout #1