Recently we've posted about Etherify a few times, mostly about how the unintentional RF leakage from the Raspberry Pi 4 Ethernet hardware is really strong and can be modulated to transmit data. In one of his latest posts Jacek Lipkowski (SQ5BPF) explores if Ethernet ports on PC's exhibit any sort of RF leakage too, and if it can be modulated into a data signal.
The answer is yes, there is some RF leakage, however unlike the Pi 4 the speed at which the leakage can be modulated is much slower, and also the signal strength is much lower. Despite the slow modulation speed, Jacek was still able to transmit data by using QRSS CW, which is essentially just very slow morse code. Using this idea he was able to transmit, and receive the CW signal with an RTL-SDR over a distance of 3 meters at 375 MHz, 625 MHz and 250 MHz. The signal strength is nothing like the Pi 4's Ethernet RF leakage which can be received strongly from over 50 meters away however.