There is a CAA document which lists the range of a small number of the NDBs
in the UK, along with the VORs.

But most of the NDBs on the 1:500,000 UK map are just not in that list at
all.

It appears that some are not working at all, or of *very* short range. I
tried to use two close by recently for some practice, & found the Compton
Abbas NDB was off, & the Bembridge NDB only useable at about 4 nm! Thats
two, quite close, both useless for most nav purposes... was I just unlucky?
(And yes, the ADF works fine on others such as Southampton & Bounemouth.)

Is there any reliable source of information on which one work & their range?
What determines which ones are in the CAA list?

Harvey