  We present 30 GHz measurements of the angular power spectrum of the cosmic
microwave background (CMB) obtained with the Sunyaev-Zel'dovich Array. The
measurements are sensitive to arcminute angular scales, where secondary
anisotropy from the Sunyaev-Zel'dovich effect (SZE) is expected to dominate.
For a broad bin centered at multipole 4066 we find 67+77-50 uK^2, of which
26+/-5 uK^2 is the expected contribution from primary CMB anisotropy and
80+/-54 uK^2 is the expected contribution from undetected radio sources. These
results imply an upper limit of 155 uK^2 (95% CL) on the secondary contribution
to the anisotropy in our maps. This level of SZE anisotropy power is consistent
with expectations based on recent determinations of the normalization of the
matter power spectrum, i.e., sigma_8~0.8.
