Misprint. Make that, "never actually used, except for limited use in training." -Hue >What do you mean it was never built? There are enough of them around to prove otherwise. I always thought the output audio taps sort of acted as a quasi-volume control. 73 – Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115