A "hybrid" focal plane counter comprising a gridded ionization chamber with position sensitive proportional counters, 300 mm long, 510 mm deep and with an active height of 60 mm, is described. The detector is designed for use with the Oxford MDM-2 magnetic spectrometer and is suitable for both light and heavy ions. Typical results obtained are 0.6 mm position resolution and 1% total energy resolution. Two energy loss, a veto and two position signals are available as well as provision for height and timing signals. Techniques are described for the reduction of capacitive noise, correction of electric field nonuniformities, and the reduction of interference from positive ions on the ionization signals.