We recently wrapped up a cross-country road trip across the US where I operated /M a few times.

During the drive, I anticipated some EMI, and the “turn-off, turn-on” game to isolate sources of noise.

As we drove, the diesel igniters of the semi-trucks I passed were coming through 59, and the hum of the AC compressor would bump up the noise floor a little. What I expected—and completely forgot about—was an aftermarket USB charger splattering noise all over the 10m band (and probably others).

Once I unplugged that, I was able to make contacts.