To answer the original question...
1) Original BITX was single-band, mostly 20M. Some were modified for other bands.
Analog (L-C) VFO was standard.
2) MKARS-80 was a UK BITX for 80 meters.
3) Kit developers then provided parts or parts and PCBs for single band BITX units.
Some of these kits were modified for other bands.
4) BINGO is an analog VFO version of the original BITX.
5) Then Nigel tested a BITX-17 for 17 Meters and kit providers followed.
6) Minima was an early attempt at an all-band (HF bands) BITX.
7) BITX-40 is a single-band version of the uBITX
It uses an SI5351A for digital VFO. The PCB is populated but you have to connect
the front panel controls and provide a case.
8) uBitx (micro-BITX) is an all-band (HF Bands) version of the BITX. It uses an Si5351a
for digital frequency control. The PCB is populated but you have to connect front-panel
controls and provide a case.
Almost all versions of the BITX have been modified for other bands, including 160M, 6M,
and 2M. Some of these mods are more successful than others.