Is Litz wire really necessary for the coil in this circuit ?
I'd have thought that the regeneration would compensate for the lower Q if the coil was wound with ordinary enamelled copper wire.
I like "neon indicator's" idea of modifying/adding a coil on a small ferrite rod aerial - good luck with your experiments !
By the way Les, I am very impressed with your web-site, it has a suitably vintage look to it. (I hope that was the intention
)
Regards,
Andy