[Boatanchors] Create log periodic antenna question

[Y S Lee]

Hello;
   I recently obtained an used Create 5130-2N logperiodic antenna
from a local ham. I installed the antenna vertically and compared receiving signal
strength with a vertical antenna. The vertical antenna showed better signal
strength than the log periodic pointing to a transmitting station. This
did not make sense because the log periodic antenna is supposed to
have higher gain. Changing cable did not make any difference.
So my conclusion is that something must be wrong with the log periodic.
I checked all element connections and the connector and all seemed fine. 
Any opnion what could be wrong?
de HL1FB/WW6N