[ADTech]

Nope, just didn't notice the question...

We haven't modeled or formally tested the performance of the 91XG when the additional section is added (and we have no plans to do so...), so anything I have to report will be anecdotal.

When I asked our design engineer about it a while back, he kind of shrugged and muttered something about "a little bit" and then something about "diminishing returns". When pressed, he speculated "maybe up to a dB or so with a bit narrower beam width". He was preoccupied with other critical projects and I never followed up on it with him.

We've had a few customers who have reported slightly better reception with the additional section. I consider myself in this category even though I didn't measure the before and after signal levels when I did my modification. For a while last year, we had a group of guys down around Kentucky Lake who were adding center sections like crazy to dual antennas with motorize tilt controls. I haven't heard from them since.

As always with experiments, YMMV.