Sorry it took me so long to respond. I lost track of this thread and just picked it up again.
The Globee is JUNK!

Now let me explain.
I have a BME 102 with a 2 blade 26x10 propeller.
My BME idles at 4000 rpm and max rpm is over 9000 rpm.
We know this is wrong.
If I aim my tach so that the sun is shining thought the propeller, I can yaw the tach and pick up a good reading about 40% of the time.
If I place the tach in front of a incandestant light bulb it reads the correct rpm and is steady (3600rpm I think).
If I put it up to a automotive strobe the reading is consistant (and realistic) 750 at idle.
I can yaw and pitch the unit and it pick up great in both of the test conditions.
The best condition that I have in actual operation is to put a very strong light (battery power) in front of the propeller and shine the into the tach through the propeller. The numbers get more consistant but it only seems to work after the sun goes down.
Anyone wants a Globee, I have one that I will sell cheap (plus shipping).
It is JUNK!