applikator, heavy stuff: audio at 200 Watts

One of RCA`s specialities is high-power transistors. Three recent additions to the range are the BO 550, BO 550A and BO 5508. These three heavyweights are intended for use in quasi-complementary audio output stages, and a few of RCA`s designs are described here. The most remarkable characteristic of the three transistors is their high collector-emitter breakdown voltage -especially the BO 5508, with its VcEO of 250 V! The main specifi-cations for the three versions are listed in table 1.