GSM Sniffing on a Budget with Multi-RTL Tuesday, January 31, 2017 Teklinks If you want to eavesdrop on GSM phone conversations or data, it pays to have deep pockets, because you’re going to need to listen to a wide frequency range. Or, you can just use two cheap RTL-SDR units and some clever syncing software. Full article Email This BlogThis! Share to X Share to Facebook