Here is an amazingly versatile circuit-- look closely and you'll see that it's really the same detector found in my article on the Superregen for FM VHF Aircraft. Turns out that this same Superregen, when used in "normal" regen mode instead of in superregen mode, makes a damn good alternative to the more well-known Armstrong and Hartley -type regens. In my opinion, it makes the best little AM broadcast-band regenerative I've ever played around with. All you have to do is scale 3 or 4 components'