Use a multimeter as a field strength meter
When debugging and repairing wireless walkie-talkies and wireless remote control toys, it is not easy for amateurs to check whether the transmitter is working properly without a field strength meter. The easiest way is to bring any test pen of the multimeter close to or contact the transmitting antenna of the device to be adjusted. (The other test pen can be left blank), if the pointer swings backward (it can be in any gear, the 100MA gear is the most sensitive), it means that the transmitter has radio waves. According to the swing amplitude of the pointer, the size of the transmitted radio waves can be roughly estimated.
It should be noted that do not directly touch the antenna with the test pen, because the radio signal of a walkie-talkie or remote control with a slightly higher transmission power can be sensed on the meter head when the antenna is far away from the test pen, so as to prevent the needle from being damaged. This method can be used for FM and AM transmitters of various frequencies. However, it can only judge the presence and strength of the signal, and cannot correct and adjust the frequency.
