Recently I was working with one of the German board members (with forum name Didjeridoo) on his CB. He had invited my impression, and I suggested that it wasn’t working quite as well as it should have been. After about two weeks of investigation, we found that the trouble was one of the crystals: http://i10.tinypic.com/2cnb0yc.jpg
The somewhat ball-shaped part on the right-hand side has quite a negative feeling, and though the part on the left is good, the combination was bad enough that it affected the whole CB. Didjeridoo made several changes, including exchanging a different crystal for the one pictured. http://tinypic.com/2q8vtzb.jpg Here is the CB now. It seems to be quite good.
This is not the first two-part crystal I have seen that had a negative effect.