has anyone else tried Lloyd Walkers latest tweak

For electro-magnetic waves to be changed to audio signals(within a detector/crystal), they must be, "absorbed." The only thing a crystal needs to do so, is an antenna. Perhaps, in the case of the wavelengths that the Walker deals with, the size or shape of the crystal obviates that need( as I mentioned earlier). Just trying to present a plausible possibility, for Mr L.

Dear Rodman, The crystal in those old radios is an RF generator, not an RF absorber. In the old days, I think those radios were "tuned" to a particular frequency by changing the crystal, each one of which resonated at a different frequency. In fact, every time I tried to do a search on crystals as an absorber of RF, I got a list of papers documenting the fact that an electrically energized crystal (not an inert crystal glued to a tonearm) will radiate RFI.

Also, if what you theorize were true, we wouldn't be having this discussion; it would be common knowledge.

Benjie, if we have parallel universes, what would they be like?

Lew & Al (Rodman), regarding the function of crystals in early radio equipment, you're both right, but you are referring to two different applications. And to some extent to two different eras.

Crystals were (and still are, in some applications) used to control the resonant frequency of tuned circuits, such as RF oscillators. While in the earliest days of radio, and later in radio hobby kits, they were used as detectors/demodulators, where (as Rodman indicated) their rectification properties were used to extract the audio information carried on AM (amplitude-modulated) radio signals.

Regards,
-- Al