Frozen Signals, Unfrozen Airwaves

The music keeps playing, but winter is trying its best to silence it. We pull back the curtain on how ice sabotages broadcast antennas and what it takes to keep a reliable signal alive through freezing rain, rime, and brutal wind. From wet-ice detuning that spikes reflected power to the jaw-dropping structural load of a tower turned into a frozen sail, this is the real story of staying on the air when the weather turns hostile.

We break down the physics in plain language: why precise element lengths and spacing drift off-frequency under a glaze of ice, and why that first conductive layer is the most dangerous. Then we get tactical. Active heating systems with temperature and moisture sensors, high-wattage elements, and even forced-air solutions for big dishes; passive protection with fiberglass radomes that block precipitation while keeping RF transparent; and the “middle path” of hydrophobic coatings that delay ice adhesion but require upkeep. You’ll hear the trade-offs that matter—power costs versus outage losses, added wind load versus electrical stability, and maintenance complexity versus long-term resilience.

Design and strategy round out the playbook. We talk fat-element antennas that resist detuning, clever high-frequency tuning so ice drift pulls you back toward target, and redundancy that lets one antenna carry the day when another ices over. Sometimes the smartest move is to monitor, protect the gear, and wait for a thaw; other times, critical sites justify every watt of heat and every ounce of fiberglass to protect coverage. If you’ve ever wondered why a station fades during a storm—or marvel at how it doesn’t—this conversation gives you the engineering, the economics, and the hard-earned judgment behind those choices.

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Episode Transcript

SPEAKER_00 (00:25):
Hey, welcome to Fully Modulated.
I'm Tyler, and today we'retalking about ICE on antennas.
Yeah, that's right.
ICE.
ICE ICE Baby.
Just a quick uh disclaimerbefore we get underway.
As usual, this podcast isn'tconnected or endorsed by any

(00:48):
radio stations, broadcastingcompanies or other
organizations.
I've uh I've been in radio since2014, a broadcast engineer since
2018, and a broadcast networkengineer since 2025.
This is just me sharing storiesand insights about radio
technology and broadcastinghistory.

(01:10):
The things that I love.
So winter is coming, and no, um,that's not a Game of Thrones
reference.
Or maybe it's already here,depending on where you're at.
And you might be wondering, howdo radio stations keep
broadcasting when everything'scovered in ice?
Well, you're about to find outbecause ice isn't just an

(01:34):
inconvenience.
It can literally take a stationoff the air.
Here's the thing when ice formson an antenna, it doesn't just
make it heavier.
It actually changes how theantenna works electrically.
Think about it.
Your antenna is carefully tunedto work at one specific

(01:57):
frequency.
Everything is calculated, thelength of the elements, the
spacing, all of it.
Now coat everything with ice,suddenly all those dimensions
are wrong.
Your antenna isn't tunedanymore.
And some companies, when theyput an antenna up, uh company
that I worked with um oncebefore, oh man, I'm blanking on

(02:20):
the name, but they wouldslightly put the antenna just
slightly out of tune.
So when it did ice up in thewinter, it would actually bring
it closer to what it shouldactually be.
Now, the worst part of this,when ice first forms, it's wet.

(02:40):
And wet ice conductselectrically electrically.
This is the absolute worstcondition for the antenna.
That wet conductive layer messeswith everything.
It can detune your antenna sobadly that you're basically off

(03:03):
the air.
The reflective power, thevisoir, gets so high that it
trips the transmitter off.
Later, the ice freezes solid anddries out.
No, it's not quite as badelectrically, but now you've got
a weight problem on your tower.

(03:25):
Ice is heavy.
And when I say heavy, I re Imean really freaking heavy.
A bad ice storm can add hundredsor thousands of pounds to the
antenna.
And remember, this thing is wayup on that tower, several
hundred feet in the air, youknow, maybe a thousand feet,

(03:46):
acting like a giant sail in thewind.
You can add all that ice, andthen the wind hits it, and
you're putting a massive stresson everything.
The tower, the mountinghardware, the antenna itself,
the towers have collapsedbecause of ice buildup.

(04:06):
Antennas have been ripped off oftowers.
I mean, it can get serious.
And then there's anotherproblem.
When the ice melts, it doesn'tmelt evenly.
One side might be shedding icewhile the other side is still
coated.
That creates an unbalanced load.

(04:29):
It can twist the antenna, stressit out.
Even worse, when big chunks ofice do start to break loose,
they can fall and hit otherequipment on the way down.
Now, imagine a 50-pound chunk ofice falling from 500 feet up.
As you can imagine, that's notgoing to end very well.

(04:51):
Um so how do how do stationsdeal with this?
Well, there are a few ways.
In which one you use depends on,you know, a lot of things.
But number one, money, yourbudget, your location, and
obviously your equipment.
The most effective method isheating, active heating.

(05:15):
Some antennas have built-inheating elements, kind of like
your car's rear windowdefroster, but way bigger.
These systems use electricity towarm the antenna and prevent you
know, prevent the ice fromforming in the first place.
The fancy ones have automaticcontrols.
You know, you know, thinktemperature sensors and moisture

(05:37):
sensors.
When it gets cold and maybe alittle wet, boom, the heaters
kick on automatically withoutany input.
Now, those type of systems,they're not cheap.
Not to buy, not to install, notto run.
We're talking kilowatts of powerjust to keep the antenna warm.

(06:00):
But for the big guys, the bigstations, for stations and
places that get brutal winters,you know, think Minnesota.
It's worth it because going offthe air will cost way more money
than running those heaters.
You can also heat antennas a youknow a couple different ways.

(06:20):
Um electric is the most common.
Heating elements running alongthe antenna structure powered
from the transmitter building.
Some big satellite dishes usedforced air.
Heated air blowing across thedish can be electric or gas.
Works great for large surfaces,but it's more complicated to

(06:42):
maintain.
Now, not every station canafford heating systems.
So there's another approach.
It's called radomes.
A radome is basically a coverthat goes over the antenna.
The name came from radar dome.

(07:04):
Radome, if you didn't guessthat.
It's made uh it's made of uhmaterial that it's it's
transparent to radio waves, butkeeps the weather out of it.
Like a jacket for your antenna.
Radarms uh radomes are reallycommon on uh satellite editions
and smaller directionalantennas, but for FM antennas,

(07:28):
you sometimes see those uhfiberglass tubes that enclose
the antenna elements.
The advantage is the radom keepssnow and ice from touching the
antenna directly, so you don'tget that electrical detuning
problem.
It's passive, no electricity isneeded, lower cost to operate.

(07:50):
But radomes, they come with constoo.
They're expensive to buy and toinstall.
They add wind load even whenthere's no ice.
And if ice does build up on theoutside of those radomes, it
stays there.
Unlike a heated antenna wherethe ice melts off, a radome just

(08:11):
sits there with ice on theoutside until it warms up.
And a harsh winter, that couldbe weeks or maybe months.
There's also a middle groundsolution.
There's a middle option.
Coatings.
Hydrophotic coatings make wateruh beat up and roll off instead

(08:31):
of sticking.
Like raineks for yourwindshield.
These can help delay iceformations, but um, you know,
they're not a complete solution.
They're expensive.
They wear off from sun andweather, so you have to reapply
them every so often.
And in really bad conditions,they can still get overwhelmed.

(08:54):
Other coatings like Teflon orPVC-based stuff, they've you
know, they've been tried a fewtimes, mixed results basically,
out of it.
They they might help uh you knowa little bit, but nothing
completely prevents ice in allconditions.
So coatings are usually usedwith other methods, not by

(09:18):
themselves.
Now, here's where design comesin.
Some antennas are built to bemore resistant to ice.
One way is using fatterelements.
When you have a thick antennaelement, ice doesn't change the

(09:38):
diameter as much as um, or Ishould say, doesn't change the
diameter as muchpercentage-wise.
Think about it.
If you've got uh you know a thinquarter inch element and you add
a quarter inch of ice, you'vetripled the diameter.

(09:59):
But if you've got a two-inchelement and you add a quarter
inch of ice, you only increasedit by about 12%.
Um the fat element, it's gonnabe less sensitive to the change,
basically.
Another uh clever trick istuning the antenna slightly
high, like I mentioned before.

(10:21):
Um so if you're on 95.5megahertz, you tune it for 96
megahertz.
Normally, this causes like zeroperformance loss.
But here's the cool part.
When ice forms, it makes theantenna elements electrically

(10:43):
longer.
That brings the frequency down.
So as ice builds up yourantenna, it actually tunes
itself closer to the you know,closer to your actual frequency
instead of further away.
The performance degrade, youknow, it degrades way more

(11:04):
gracefully.
For really important sites, um,you know, some places use
multiple antennas.
If one gets ice build up reallybad, the others pick up the
slack.
It's not perfect, but they'reall they're all in the same

(11:25):
weather.
I mean, uh, but if the icingisn't perfectly even, even
backups could help.
Then there's the brute forceapproach.
Just let it happen.
Some stations, especiallysmaller ones and areas that
don't get bad winters, they justaccept it.
They'll have reduced coveragefor a few days, or you know, you

(11:49):
know, a few days out of the yearwhen it's really bad, they'll
monitor everything, make surenothing's getting damaged, and
just kind of wait it out.
When it warms up, the ice meltsand they're back to normal.
And finally, there's manualintervention.
I've heard stories of engineersclimbing towers in the winter,
which I do not recommend toremove ice and check for damage.

(12:14):
Now, like I said, that'sdangerous work.
Tower climbing is already one ofthe most dangerous jobs in
broadcasting at ice, and it'sexceptionally worse.
This is a this is last resortonly.
Only when there's no otherchoice, and only by people who
really know what the hellthey're doing.

(12:34):
The reality is ice management isjust one of many challenges that
we as broadcast engineers face.
In summer, we worry aboutlightning and overheating.
In winter, it's ice and snow.
Year round, there's maintenance,failures, power outages, all
kinds of stuff, network loss.

(12:55):
I mean, anything, any number ofthings can go wrong.
But that's that's what makesthis job interesting, right?
At least for me.
They're constantly probablyproblem solving, adapting,
finding ways to keep the signalgoing no matter what.
Every station's situation isdifferent.

(13:15):
Different location, differenttower, different equipment,
different budgets.
There's no one solution thatworks for everybody across the
board.
The stations that do it right,they probably plan ahead.
They invest in the rightequipment for their situation:
heated antennas or radomes,ice-resistant designs, whatever,

(13:35):
whatever works for their budgetand their situation and their
location.
They have backup plans, theymaintain their gear, they have
engineers who understand thesystems and can respond fast
when things go wrong.
So the next time you'relistening to the radio during a
winter storm, take a second toappreciate what's happening

(13:55):
behind the scenes.
There's an antenna way up on atower somewhere, either being
heated, protected by a radome,or just tough enough to handle
whatever ice is forming on it.
And if you do lose a stationduring the storm, well, now you
know why.
It's probably ice.
The engineers are probablyalready working on it, or

(14:19):
they're waiting it out.
And as soon as they can, they'llget it back on the air.
That's what we're here for.
That's what we do.
Thanks for listening to FullyModulated.
If you enjoyed this, pleasefollow the show on Apple Podcast
and Spotify and leave a review.
It really helps other peoplefind the show.
I think.
I don't know.

(14:39):
Nobody's ever shown me the dataon that.
If you have uh if you havequestions or ideas for future
episodes, email me, Tyler atfully modulated.com.
You can also find the show onFacebook at Fully Modulated, on
Instagram at Fully ModulatedPod, and on Bluesky at Fully
Modulated.com.
This is Fully Modulated.

(15:00):
I'll catch you next week.