790hz is the switching signal, as the contacts corrode the resistance increases so they have to be tested on a schedule.
Comment on [Question] Metal Sign on Railroad Says "790Hz"
sketchyenchantment@sh.itjust.works 9 hours ago
You should check out this patent. When the train goes over a special section of track, it will trigger the signal at the nearby crossing
in_my_honest_opinion@piefed.social 9 hours ago
rudyharrelson@lemmy.radio 1 hour ago
Ahh, that makes sense. Thanks for the assist!