Not sure how much use an ADF is these days!
It's used purely to make IR(R) renewals a bloody misery.
Doncaster which is my local 'go to' NDB approach sees me once every two years...can't see the point of them, flying holds over them is a pain, they drop out, point the wrong way in bad weather. I hate them. WWII technology and here we are 75 years later in the age of GPS, ILS. RNAV and we still have to trot out the 'We'll do a hold to NDB/DME approach for your second PIA.' You may as well add 'And we'll do it in a Sopwith Camel.'