You seem to have it working to your satisfaction now, so this follow-up is just a curiosity post:

The pre-amp for this antenna appears to be a little rectangular box integrated within the antenna "box" itself. As such, it does not appear to be removable at all. There is an extra "in-line" gizmo which serves as a DC power injection module, to supply remote power to the antenna.

The placement of the power-injection module is generally unimportant in the set-up: it can be right next to the TV if desired. All it consists of internally is a tiny capacitor to block the injected DC power from going to the TV set, and then a DC jack for power connected directly to the coax middle conductor and sheath, going towards the antenna/pre-amp.

With this physical configuration, it is possible to remove the power-injector from the setup, but the pre-amp itself seems to be hardwired into the antenna (that little rectangular box) and probably cannot be removed.

Some pre-amps still pass signal when not powered, though at a significant loss. Others cease to pass any meaningful amount of signal unless powered.

It is possible they have provided mis-information (aka. "they lied") in the description though, and the entire pre-amp circuitry could instead reside within the "power injection" module. Dunno.

Cheers