The full correlation analysis (FCA) of spaced antenna (SA) data is sometimes found to be susceptible to the triangle size effect (TSE), whereby the magnitude of the FCA true velocity increasingly underestimates the actual wind velocity with decreasing antenna spacing. The TSE has been attributed to a number of instrumental effects, including coarsely digitized data, receiver characteristic differences, noise, and antenna coupling. In this paper the sources of the TSE are discussed, and the influence of various previously undocumented instrumental effects upon the FCA are investigated using simulated data. These additional effects are also shown to produce the TSE. The possibility that these instrumental effects may contribute to the lack of agreement exhibited between winds estimated using medium frequency SA radars employing the FCA and alternative in situ, satellite, and other radar techniques is discussed. ¿ 1999 American Geophysical Union