Here is the FB set up Larry is running. The receiver is a Collins 75-A4. Exciter is a Plate Modulated Johnson Challenger fed with a direct synthesis vfo and a Mc Intosh MC-40 as a tube modulator driving an audio output transformer backwards to the plates and screens╩of the Challenger. It also has an adjustable screen control for power adjustment. That drives a 3 tube Alpha 76 A, although a plate modulated pair of 4-400's is under construction. Audio processing is an Orban Optiomd-AM 9000A fed with an Ampex tube mic pre. Microphonium is a Shure SM-57. Antenna is an inverted trap-dipole.