The meter is an Acoustimeter Model AM-10, frequency response is 200MHz to 8GHz. The meter gives an audio translation which is typical of RF meters. This is helpful because it allows you to recognize what is what with a little practice. A cell tower for example sounds different from a cell phone, router, and so on. The signal in question was at a peak signal strength of 3.41 V/m near the router. Was just a short blip about every three seconds, not a usual sound or signal to come from this particular router, especially since the Wi-Fi was turned off. It normally doesn't broadcast any signal. The signal wasn't happening the next day, but started up again in the evening. For info, digital signals differ from a steady analog signal because it is transmitted in blips or bursts of data separated by intervals of no signal.