Does anyone have practical experience using AA batteries with D size battery
adapters with a Tecsun BCL 3000 radio? If I get a good quality set of
2700 mAh AA Powerex batteries along with a set of D size adapters, how long
will they last compared to a set of D size alkaline batteries?

I was thinking of getting a D size battery charger but the cost of a good
one is pretty high. I've got a very good AA battery charger already, so I
am exploring the cheaper route.