The metric that WifiPROBE uses to compute the best channel requires that ‘% Available TX’ be compared against a baseline reference measurement for each channel. This baseline represents 100% Available TX — that is, no RF interference (or, as close as possible). To achieve this we’ve included a 50 ohm SMA terminator to be attached to the antenna connector. Furthermore, if you have a microwave oven available, we recommend placing the unit in the microwave oven during the duration of the calibration procedure (approximately 1 minute). And, of course, DO NOT use the microwave oven during this period. The microwave oven serves as a “poor man’s” Faraday cage. The combination of using the SMA terminator plus microwave oven closely approximates an RF environment with no RF interference — which will define our baseline of 100% Available TX. During the calibration procedure the unit will traverse all the 2.4x and 5x GHz Wi-Fi channels and record a baseline value for each channel. When you later use the device for WifiPROBE channel analysis, the value it measures will be compared to the corresponding baseline value and the ‘% Available TX’ can then be computed and displayed on the screen.

The calibration feature can be accessed by selecting ‘Configuration’ from the main menu, followed by ‘Re-calibrate’ in the CONFIG MENU.

For the next step, the menu reminds you to ATTACH THE 50-OHM SMA TERMINATOR (“DUMMY LOAD”). Also, if you have a microwave oven available, we suggest you place the unit in the microwave oven during the duration of the calibration procedure (approximately 1 minute). The goal of the calibration step is to approximate 100% Available TX time, and the combination of dummy load plus microwave oven serves as a “poor man’s” Faraday cage. Once you press the UP key there is a delay of 5 seconds before the calibration process begins. This allows a few seconds to place the device in a microwave oven before the calibration procedure begins traversing channels and recording their baseline reference values. Once calibration has completed, remember to replace the SMA terminator with the dual-band antenna.