[TenTec] was OT: Indoor Antenna: re B&W type terminated dipoles

[Stuart Rohre]

The efficiency of a dipole is nearly 100 per cent or 1.0.  Depending on 
construction, it might be 99 per cent, (0,99, 0,98, etc.)  It is as 
others stated a statement of power minus losses, giving what is radiated.
A half wave dipole converts almost all the available power to radiation 
is another way of looking at it.

Coupling factor is something else, usually applied in my experience to 
relations between tuned circuit inductors.
Not familiar with such a term being used about Yagis.  As always, a trip 
to Kraus's "Antennas" 2nd Ed. may prove useful.

-Stuart Rohre
K5KVH