BUT WAIT !! THERE MUST BE MORE !!
Something doesn't jive here. As I mentioned, I have a local friend who has one and I'm sure he's read the manual - so he was telling me that the Antenna System used needs to be 1/4 wave of the targeted frequency and that by itself makes sense. HOWEVER .... the specs state that the device works between 24~1766MHZ and they make and sell you this Antenna Set. Well THAT set can only be 1/4 wave within a megahertz or two of wherever they are constructed at ..... looking kind of short. SO are you telling me that they are making and selling you an antenna set for their very wide-banded device that only works well in one little frequency spot? That doesn't make sense. - I have an inquiry into my friend and I'll report back what he says. He's an engineering type and methinks my question will make him dig up the truth of the the things.
.
My initial bet here is that the Antenna Set they sell you WILL work anywhere the device does. It's efficiency may wane on both ends of the capability .... but should still work anywhere .... especially if you can get reasonably close enough to the signal.