Why do some radio towers blink?

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Why do some radio towers blink?

warrenm

Comments (99)

skinwill
I worked at a television station years back that was designed in such a way that the lights going up the tower were powered by the separate phases of three phase AC with the one at the top powered from all three combined. This was pretty normal but what the engineer had done was rotate them at every level so that if a phase was dropped you could count the lights and quickly see from a distance that the power wasn't right. 4 lights was good, 3 meant you dropped a phase, and so on. I thought it was a pretty clever way of keeping light on all sides of the tower while being able to tell from a distance that a phase was out.
Terr_
> Joe: [...] So whenever there's a project on the tower, it's not unusual to see the guys in some kind of a, what do they call those?> Jeff: A full ghillie suit? Or I don't know what they're called.If you see someone up in a tall tower wearing a ghillie suit [0]... that sounds like time to call emergency services while avoiding their line-of-sight. :p(Perhaps they meant "Hazmat" [1])[0] https://en.wikipedia.org/wiki/Ghillie_suit[1] https://en.wikipedia.org/wiki/Hazmat_suit
scblock
FAA details the marking and lighting requirements here: https://www.faa.gov/regulations_policies/advisory_circulars/...
alex_young
I love the narrative storytelling here, but the takeaways seem somewhat obvious.Lights on towers mean stuff, especially to airplanes.Lights are required for tall towers, and get this, towers next to airports.You can guess how tall a tower is by looking at the lights.
wil421
At my work we are working on automating NOTAMs when our tower lights go out.
barbazoo
These beacons are also great for navigation. Aeronautical charts usually show the color/pattern of the light. You can use those as points to triangulate your position.
rollulus
Slightly off topic: typically, lights of neighboring towers blink asynchronously. But sometimes they are synchronized. Very satisfying. Anyone knows how this works? My best guess is e.g. DCF77. Thoughts?
gchokov
that article is incredibly hard to read. Luckily, an AI can summarise it in seconds.
ofalkaed
In the past year or two they have also added a quick periodic flash of white light for when visibility is low; like a camera flash that happens every few seconds. I think it was added this spring but don't quite remember.
not4uffin
Figured it was something to do with aircraft communications.I live near an airfield and the runway has flashing white lights at night to help guide the aircraft's.
loph
It's not just radio towers. I've seen aircraft warning lights on tall buildings, particularly those near airports.see https://www.ecfr.gov/current/title-14/chapter-I/subchapter-E...
spc476
Changing a radio tower light bulb is not for the weak of heart: https://www.youtube.com/watch?v=9b9LahaBJIk
lxgr
Related: Some wind turbines apparently only turn on their position lights when there's any aviation traffic nearby (as detected by either local transponder interrogators (possibly ADS-B receivers?) or radar)!
pizzalife
This blog post has a really verbose format.TLDR; White lights are used during the daytime, red lights at night (less annoying), towers under 200 feet don't need blinking lights.
ortusdux
Blinking the lights also helps prevent bird deaths - https://en.wikipedia.org/wiki/Towerkill
punnerud
Never seen a blinking light on a tower in Norway. Why the difference between countries, can’t be that huge difference risk if some don’t have them?
ikkun
the towers in my area all switched to LED recently. the slow, glowing blink of the incandescent ones probably isn't as visible as the modern ones, but I do dearly miss seeing it out my window.
hinkley
Why do some radio towers NOT blink? Is the better question.
WalterBright
Blinking uses less power.
Razengan
To clean their eyes?
LargoLasskhyfv
Flugwarnbefeuerung
ck2
muuuuch better article, lolhttps://www.jeffgeerling.com/blog/2024/what-happens-when-you...
huflungdung
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comrade1234
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