I'm currently bringing an R-61/ARQ-5 receiver back to life, and the tag says it takes 400 to 2600 Hz power. I've also seen that spec on a couple of other pieces of gear. Why the spec for power up to 2600 Hz? Were there any power systems that went up that high in frequency? Just Curious Jack Jack Antonio WA7DIA scr287 at sbcglobal.net