This guide provides information that is useful in constructing an open area test site (OATS) used to perform radiated emission measurements in the frequency range 30-1000 MHz. The guidance herein is not mandatory. Adherence to the infor­mation, however, will be very helpful in not mak­ing obvious construction errors. Final validity of the test site can only be made by performing site attenuation measurements described in ANSI C63.4-1988 [1],1 paragraph 4.1.3.