We cannot just connect our coax directly to a Beverage antenna, including a BOG. A simple transformer is required for the following reasons:
- To match the low impedance of the coax to the higher impedance of the Beverage antenna.
- To isolate the feedline from the antenna, in order to avoid common-mode pickup of unwanted signals and noise on the coax shield.
You'll also need a ground. A half-dozen rather short radials laid on the ground at the feedpoint should do.
Instructions for making a good transformer, ground, etc. is at
http://www.w0btu.com/Beverage_antennas.html