The properties of planar high-temperature superconducting Josephson junctions are not entirely consistent with lowTcmodels. Some of these disparities may be intrinsic, related to the unusual superconducting properties of the electrodes, while others are due to the nonstandard planar geometry. By comparing experimental measurements of a 24° bicrystal substrate Josephson junction with a simple model of nonuniform current flow in a planar geometry, we show that several unusual properties can be explained as extrinsic. We show that nonuniform current feed in a planar geometry leads to a reduced critical current, an unchanged Meissner fieldHco,and a power-law dependence of the critical current onHcodifferent from that expected in an overlap geometry. ©1997 American Institute of Physics.