The design of AC adapter filter circuit has great influence on radio. If the filter circuit is well designed, the receiving noise of the radio will be smaller; If the filter circuit is not well designed, the receiving noise of the radio will increase obviously.
If your radio is Desheng R9702, you can consider choosing the power adapter of Desheng DC-05A.
And to explain, I also used this power adapter with Desheng R9702 radio.
Of course, if you can find a power adapter with a power supply of about 4V and an output current of more than 250mA and a better filter circuit to match your radio, the reception effect will be better.
● The above content is "I don't know", written according to my personal experience. The above contents shall not be copied or modified without authorization. If you want to quote, you need to indicate the source.