Radial structure of impulsive hard X-ray and microwave sources in solar flares is not well known at the present time. Measurements of near-the-limb flares with a high spatial and temporal resolution is, of course, the best way to determine the radial structure of these sources. In absence of such measurements, particularly for the hard X-ray emission, behind-the-limb flares provide (through occultation) a means of observing the coronal part of the impulsive source. Here we summarize the characteristics of the impulsive coronal X-ray source deduced from multi-spacecraft observations of a behind-the-limb flare and their implications with respect to impulsive microwave source.