[en] A radial field drift chamber has been incorporated with a multiwire proportional chamber to image x-ray photons from a point source. Positional information is obtained from the rise time of the terminal signals from orthogonal RC lines associated with the chamber cathodes. The detector has a useful object plane of 140 mm x 140 mm. Resolution is approximately 0.4 mm (RMS) in one direction but is limited in the orthogonal direction by the anode wire spacing. Comparison of picture quality is made between uniform drift and radial drift field detectors. (author)