Originally Posted by Yaamon
...did you point each antenna for max signal and when you connected it to the combiner/splitter/pre amp did you notice any drop in signal and had to repoint of of the antenna?
If we superimpose the top-down graphs showing the receiving apertures of the CM4221 and CM4228 and start to turn one of the antennas we find that strong lobes and weak zones from the other antenna may be overlapping or working against it. This would of course be true if the baluns are out of phase but you've already said that you figure that's not the case, and your results seem to prove that, so I think there may be something a bit more subtle happening. My guess is that you had to turn the antenna farther than you thought in order to get a good signal because an overlap or convergence in the lobe or null patterns was causing problems at that specific azimuth. I welcome anyones' thoughts on whether nulls and lobes can weaken eachother in this kind of scenario when the baluns are in phase.