Suppose \Lambda \subseteq \RR^2 has the property that any two exponentials
with frequency from Λ are orthogonal in the space L2(D), where D
\subseteq \RR^2 is the unit disk. Such sets Λ are known to be finite
but it is not known if their size is uniformly bounded. We show that if there
are two elements of Λ which are distance t apart then the size of
Λ is O(t). As a consequence we improve a result of Iosevich and
Jaming and show that Λ has at most O(R2/3) elements in any disk of
radius R