Hi!
All wall chargers (that comes in Futaba, JR, Hitec and Spektrum radios) that put out 50-150mAh ca be used to charge most NiCad and NiMH batteries!
In case you got a 50mAh wall charger and a 4,8 or 6V , 2000 or 2800mAh NiMH battery ...you just charge longer time ! I have done so for the last 25 years and it works just fine.

The problem with all fast chargers (have several) is that they all false peak when charging NiMH cells! This mean they will cut the charge before the battery is fully charged! If you understand that and want to live with this, Fine! But for ordinary NiMH batteries in receivers and transmitters I use my thrusty 30 year old JR chargers (3 of them).

By the way...are you still using NiCad batteries in America???
Over here in Sweden NiCad batteries was faced out 10 -15 years ago. All our radio systems contain at least 1500mAh NiMH batteries , both in transmitter and in Receiver.