I built this circuit and it works fine:
It's based on the noisy regen by Alan Yeats and whoever before him.
It kinda looks over complex but when you build it there is not that much to it.
I may try the Green LED FET circuit with the AM detector portion of the circuit because while the (noisy) differential pair Q multiplier is good I don't think it is the ultimate, maybe it is the ultimate in a practical sense?
I only tried the circuit on the AM broadcast band, I'll see what happens when I go up the frequency range.