I plan to build something similar using a separate BPF and LPF each for 160m, 80m, 40m, 30m, and 20m. ?Call it FrankenBitX, BruteForceBitX, or maybe DontKnowWhatImDoingBitX.
It would work without individual filter sets for each band, but I do not really understand filters yet and have not yet built Ashhar's Specan.
Ashhar's uBitX is an elegant design, and I have gathered the parts to build a uBitX, but construction will take weeks or months (for me, anyway).
A multiband-converted BitX similar to yours could be assembled in a few hours, and that's just sooooo tempting.
Care to offer any suggestions, advice, or (constructive) criticism?
73 de w9ctw