Possibly used a cassegrain antenna. Elements derived from Smerch series radar. Search range 30km, tracking range 15km versus a 16 sq m target.
Was fitted to the MiG-21S, used in Soviet service only from 1965 onwards.
Was fitted to the upgraded MiG-21SM, also not exported, and later equipped the MiG-21bis which was exported once the RP-22SM was no longer considered “sensitive”.
Probably RP-22SM-A (version for warpac).