Pinsky, Stanton and Trapa \cite{PST} %(J. Funct. Anal. 116 (1993), 111--132) showed, for example, that the spherical partial sum of the Fourier series or the Fourier transform of the characteristic function of the $n$-dimensional ball $|x|\le 1$ diverges at $x=0$ when $n\ge3$. We point out that, in three dimensions, the square partial sum of it converges at $x=0$. Let $\varphi$ be a function of bounded variation with compact support. We show that, for the radial function $f(x)=\varphi(|x|)$, $x\in \mathbb R^3$, the square partial sum of the Fourier transform converges to $\varphi(+0)$ at $x=0$.