Topband: antenna question

[Art Snapper]

This question is about bi-directional beverages, or more specifically BOG's
using a reflection transformer.

How does the loss on the forward and reverse direction compare to an
omnidirectional reference antenna?

I am not sure I worded that properly, but let's say the following was
observed.

Reference antenna = 1dBi.
BOG Forward direction  = -20dBi.
BOG Reverse direction  = -30 dBi

Would a difference like this be expected? Or is there too much variation to
predict?


Art NK8X