BConstructions

Given a Ferrero pair $(N,\Phi)$, let $\mathcal B=\{\Phi a\cup\{0\}\mid a\in G\setminus\{0\}\}$. This will give us a Difference family if and only if $\Phi a\cup\{0\}$ is always a subgroup of $N$ or if $\Phi a\cup\{0\}$ is never a subgroup of $N$. The Complex plane model here is rays, or circles with a center.