The accuracy comparison between this signal source and professional comprehensive measurement is basically the same. The accuracy is very high. Can test the actual receiving sensitivity of the walkie-talkie. Features: Suitable for FM walkie-talkie debugging. Built-in 800Hz audio modulation, with the analog digital CTCSS function. The unit is DBM. General hand sensitivity is -120DBM to -130DBM. The greater the sensitivity to a negative number, the higher the sensitivity. The signal source cannot input power. It is absolutely forbidden to press the intercom button to transmit when testing. (self-matching power supply 8V-12V power supply polarity is positive and negative) Specifications: Material: ABS Color: blue Frequency: 0.5MHz-470MHz Signal strength: -70-132dBm Built-in 800Hz audio modulation Add the analog digital CTCSS function Use 8-12V DC power supply, frequency 7 digits For example: 439.6000MHz shows 4396000KHz Signal strength -70-132dBm valid, other values are invalid. Audio modulation is only about 800Hz, other values are invalid. Item size: 155 * 120 * 63mm / 6.1 * 4.7 * 2.5in Item weight: 271g / 9.6ounce Package size: 210 * 160 * 70mm / 8.3 * 6.3 * 2.8in Package weight: 303g / 10.7ounce Test methods: During the test, the frequency of the signal source input transceiver is first set to -100DB or any value. The intercom has audio output and then reduces the output strength of the source. For example, the -120DB just heard the intercom audio signal but there was noise. The audio signal just hears that the -120DB value of this output is the receiving sensitivity of the radio. Package List: 1 * 0.5MHz-470MHz Signal Generator for FM Radio