Adjusting Foxtrak tx audio using an SSB/FM receiver exploiting Bessel zeros to calibrate the modulator

This article explains a method of setting the tx audio level of a Foxtrak using an SSB/FM receiver exploitingĀ  Bessel zeros to calibrate the modulator. Whilst the Foxtrak is used in this example, the method can be used with any tracker or TNC that allows single modem test tones to be transmitted. Continue reading Adjusting Foxtrak tx audio using an SSB/FM receiver exploiting Bessel zeros to calibrate the modulator