Apparent longitudinal variations of Ogo 3 observations of VlF chorus activity have been interpreted in terms of excitation by power transmission lines. An alternate possibility is that the observed longitudinal distribution is a result of the convolution of the latitudinal and local time distribution of chorus in space with the spatial coverage of the Ogo 3 spacecraft. The orbital period of Ogo 3 was such as to beat with the earth's rotation every 89 days and thus would produce four geographical peaks from a survey of 1 year of data.