tekati

Or if you are using say a Futaba style charger cord reverse the positive and negative leads to the charger. Now with that said I have had the polarities reversed before myself and the charger told me that the polarities were reversed and would not even try to charge the radio. The only way that it could have blown the fuse is if that particular radio maybe has a diode in it to prevent discharging through the charge jack and the charger could not detect the reverse polarity.

But in short I have used a Futaba charger cord in JR radios simply by putting the red wire in negative and the black wire in positive on the charger. From a electronics standpoint this effectively does the reversing of the polarity.

DISCLAIMER: I have done this and it works just fine. If you do this and it blows up your charger, transmitter and or house its not my problem. Proceed at your own risk.