I dug up some data on the Televes BII that I'd actually downloaded last summer when Solid Signal started carrying it. I went back to the source for the following.
Here's the gain vs frequency plot which is posted on Televes' website:
And their datasheet:
http://www.televes.com/sites/default...030214_001.pdf
The G/F plot clearly shows that this antenna is designed for Euro-Asian BIII operation as it peaks out around 230 MHz, much like the Chinese-mad high-VHF models that MCM is carrying. That channel band conveniently includes the North American channels of 7-13 so it's a good enough although not optimized match. The peak gain shown for the USA channel 13 is around 8 dBi with the majority of the high-VHF band averaging between 7.5 and 8 dBi for the BIII. In all, very typical behavior of a Yagi with 5 directors and 1 reflector, pretty much heads-up with our ClearStream 5.
FWIW, Solid Signal, the only US seller that I've seen for Televes' antennas, shows the BIII as "Discontinued". Where might you plan on getting one, if I may ask?