Why set bandwidth for Ailunce HD1

When setting the radio, we need to set many parameters, such as receiving, transmitting frequency, CTCSS, bandwidth, etc. We know that if the set receiving and transmitting frequency and CTCSS are incorrect, normal communication cannot be achieved, but in general, no matter the setting Whether the bandwidth is wideband or narrowband, the impact on communication is not so obvious. So, why do we set bandwidth?

For amateur radio, such as HD1, the bandwidth in analog mode is also called spectrum bandwidth, which refers to the maximum frequency bandwidth of the signal that can effectively pass through the channel. When setting, you can choose wideband or narrowband. When the received signal strength is high and the transmission distance is short, the effect of wide and narrow band may not be obvious, but if the received signal is far away and the signal strength is weak, the amplitude of the modulated wave in the broadband mode is large, and it is easier to receive some , The sound quality is good, but the frequency bandwidth is occupied; while the narrow band may cause problems in the reception of the walkie-talkie, because there may be a little deviation when transmitting, and the signal can be received better only if the bandwidth is set wider.