Product Feature: 1. Simple and efficient appearance, beautiful and generous 2. Wide frequency band, high sensitivity, 100KHz-1000MHz (the original antenna is 400-470Mz, please use antennas with different frequencies to test signals at different frequencies for better results and sensitivity) 3. Adjustable pointer amplitude (to protect the meter head) 4. Built in automatic damping function, also known as buffering function, to prevent damage caused by rapid swing of the watch needle 5. Small size, easy to carry 6. Test sensitivity: (1) 0.1W transmitter distance 0.1-1 meter (2) 2W/5W transmitter, 1-3 meter range (3) 10W transmitter distance 2-5 meter range (4) 50W approximately 3-10 meter range Using the HP8921A radio comprehensive tester to test the sensitivity to -20dbm, just started the meter, and -2dbm can fill the meter (the sensitivity may vary depending on the video rate) 1 Instructions for use: Before use, please rotate the "amplitude adjustment" to the far left end. The length of the antenna to be opened should be determined based on the test frequency, preferably 1/4 wave. The handheld walkie talkie should be about one meter away from the field strength meter, and should not be too close! To prevent the signal from being too strong and burning the field strength meter! Then press the PTT button on the walkie talkie to enter the transmitting state. At this time, the pointer of the field strength meter should have a signal indication, and the stronger the signal, the greater the indication! Amplitude adjustment: If the pointer indication of the field strength meter exceeds the maximum range, the "amplitude adjustment" can be adjusted to allow the pointer to indicate the appropriate position. 2 Method for testing the maximum gain point of antennas In order to facilitate and quickly change the frequency, a frequency intercom with a keyboard should be selected for manual setting. 2. Connect the walkie talkie to the antenna feeder, place the field strength meter near the antenna (distance depends on the environment), try to place it within the vertical radiation angle of the antenna, and it is best to plan the antenna in the same way. 3. Set the frequency of the walkie talkie, press the transmit button, observe the meter reading, and register the meter reading at this frequency point. Then set the walkie talkie to another frequency point, put the walkie talkie into the transmitting state again, and observe the meter reading Then compare the readings at each frequency point! You can determine the optimal frequency point/band of the tested antenna! Attention: This is a passive field strength tester used for testing walkie talkies, not for testing remote controls!!! Shipping list: Field strength meter X1 Antenna X1