For hams, QRP refers to transmitting at reduced power. QRP radio means very low-power radio, normally 5W or less power. QRP Communication is one of the more exciting projects in the activities of amateur radio.
As we know, amateur radios are allowed to use up to 100 watts of power, and in some countries of the world, such as the United States, hams can even transmit up to 1,500 watts of power. QRP hams believe that this kind of high-power transmission is unnecessary. It not only wastes electricity and increases interference to nearby TVs, radios, and phones, but also for hams in the United States, it also violates FCC Part 97 regulations, which must use the "minimum power required for the required communication". QRP communication meets this requirement. In addition, QRP communication is also very suitable for emergency communication during disaster recovery. because it is very important that the available battery power and generator fuel are also used sparingly. Therefore QRP is also particularly suitable for field communication and emergency communication.
When using a QRP radio to communicate, a good antenna is essential. In the process of antenna debugging and trimming, in addition to the SWR, the characteristic impedance also can't be ignored, and need to try to adjust to about 50Ω. Only when the QRP radio, transmission cable, and antenna are better matched, the lower output power of the QRP radio can be radiated through the antenna oscillator as much as possible, and the weak QRP signal of the same frequency can be received. In addition, we should try our best to choose a place where there is no strong signal from other higher power radios, and be patient, and scan the communication frequency. If the signal is unstable when replying, we can answer multiple times or record and wait for the next opportunity to answer.