I vaguely remember a TV show, in the early 80's, where a kid repairs an old tube car radio, and it picks up a station that appears to be playing music and programming from the 40's (when the radio was made). It turns out the kid replaced a coil (probably the local oscillator coil) with a wrong one, and that made the radio pick up a nostalgia SW station. And it was a nearby station, which had enough signal strength to barge its way past the MW antenna circuit, and also explained why only the one station could be tuned in. The kid became disappointed by this mundane explanation, as he though he created a time machine radio or such...
Well, what do you expect of a plot written for a TV show...
