Xact X2X 2-way radio charger problem

Dear Sir/Madam,

During a visit in the US I purchased a couple of X2X wrist watch 2-way radios, including the adapter. I enjoyed the product very much. When I returned to Israel, where I live, I tried to recharge the batteries, and I used 200-to-110V adapter, to which I plugged the original XA10 adapter. Unfortunately, due to malfunction of the down-converter, the XA10 adapter burned out. I want now to buy a transformer, here in Israel, and to use it directly as the adapter for charging my X2X batteries. I understand that the adapter output should be rated 9VDC @100mA (2.2W). I need only information regarding the plug that goes to the wrist-watch. It looks like stereo-headphones plug- and I need to know the polarity of the voltage, namely, on the three terminals, which is the positive, the negative, and what is the third one. Please help me with it. I want to enjoy the 2-way radio here, just like I did in the US. Thank you in advance, Dr. Y. Gofer

You would have to hope that the 110Vac - 9Vdc plug adapter, in failing, has not subjected the wrist radio to a severe overvoltage since this would possibly make it un-repairable.

To find out the correct polarity for wiring the plug you should dismantle the dead adapter and identify the cable connections back to the internal circuitry. The cable will probably connect to the pcb where an electrolytic capacitor is the last dc filtering component before the cable connection. Since the capacitor is across the dc output supply and is polarised (black line on side of cap = negative), you can trace the connections to the corresponding conductors in the output cable and hence to the associated connector rings on the plug. The other terminal onthe capacitor will correspond to the positive output conductor. Check out both conductors using a multimeter on continuity check or ohms position.

Good luck.