How about reset to factory?

Compared with business radios, amateur radios have more and more complex functions, so the operation and setting process often leads to abnormal use intentionally or unintentionally. Therefore, almost all amateur radios allow to reset to factory.
Take HD1 as an example, press the MENU&EXIT keys at the same time and turn the power-on knob clockwise, the screen will display as shown below.

We can select VFO or ALL through the up and down keys. When we just want to reset the channel setting information, such as the settings in the Band A Set or Band B Set menu to the factory information, select VFO; but if we want to restore all the settings of the radio , including all setting items under Main Set, you need to select ALL.
In addition to HD1, Retevis RT73 and RT3S can also restore factory mode, but only support overall reset. In addition to the one-key reset the radio itself, we can also reset to factory of the whole radio by writing the factory CODEPLUG in the software. The most prominent advantage of this method is that we can find out the abnormal setting points by ourselves by comparing the setting parameters. For example, TOM found that the sound of RT73 was hoarse and unclear after he only made the codeplug of RT73, but after comparing the factory codeplug, it was found that the microphone gain setting was abnormal. , modify the microphone gain to the factory parameters.