I discovered some cheap Chinese radios have subpar battery replacers for "mobile' use. The plug in power supply provides enough volts and amps for receiving, but not enough amps for transmitting. After poking around I found some guys using the LM2596 DC-DC buck/boost chip to get enough power to run their HTs in a mobile or base station role. As long as the power source supplying the chip pushes more than 1.5Amps the HT will transmit. I set my chip for 8.3V and wired it to female(?) 5.5mm barrel plug for greater flexibility.