Somehow this does not make sense, I too am RF knowledgeable, worked over 32 yrs in the field and never heard of an antenna with this gain unless it is a dish

Item 53-6165-3
HDTV Indoor/Outdoor
Passive Antenna
Anti-UV coating and waterproof design lightweight. Compact size and easy to install with dipole in-built for the excellent UHF and VHF band signal reception
Frequency Range VHF: 174-230 MHZ, UHF: 470-862 MHZ
Antenna Gain VHF: 20 dB, UHF: 30 dB
Impedance 75 Ohms
Noise Figure ≤ 3.5 dB

Most of the gains specified should be reference a dipole dBi, based on this, the antenna would need at least, ten folded dipoles, 3 dB increase for each dipole set.

The possible reason chn 9 came in, is most UHF flat panels do not go down that far in frequencies or the pre-amps used are UHF only.

My two cents (nickels after September)