From Crackle To Clarity: The Rise And Fall Of AM Stereo

Forget the crackle. We dive into the secret life of AM stereo—the late-night rabbit hole that led us from a Wyoming station’s YouTube clip to the engineering that once promised FM-grade sound on an “old” band. We break down AM versus FM in plain terms, then follow the 1970s and 80s race among Motorola, Magnavox, Harris, and Khan to deliver true stereo on AM without abandoning listeners with mono radios. The result is a story of elegant design, messy standards, and a pivotal FCC misstep that left drivers and DJs caught between systems.

You’ll hear how C-Quam became the most practical path to AM stereo, why the Harris AMS G1 exciter made upgrades almost plug-and-play, and how a handful of stations proved music on AM could feel big, warm, and alive. We talk through the lawsuits, the car radio confusion, and the quiet truth that many “limits” of AM were set by policy choices and crowded dial conditions, not the raw capability of the gear. With real-world examples—from KEVA’s stereo oldies to pockets of Canada, Australia, and Japan—the episode paints a vivid picture of what might have been if the industry had moved faster and agreed sooner.

If you’ve ever wondered why AM sounds thin, or if it has to, this tour flips the narrative. Great processing, smart exciters, and clean spectrum can turn AM into a surprisingly immersive listen, especially for classic rock and soul that rely on stereo space. Stick around for a candid takeaway on timing, standards, and how technology wins only when it meets listeners where they are. If this story made you rethink AM radio, follow the show on Apple Podcasts or Spotify, drop a rating or review, and share your own radio memory—does your dial still hide a stereo surprise?

Send me a text message with your thoughts, questions, or feedback

Visible Wireless by Verizon
Same Verizon coverage, way cheaper bills. No contracts or hidden fees. $20 off for both of us.

Support the show

If you enjoyed the show, be sure to follow Fully Modulated and leave a rating and review on Apple Podcasts or your favorite podcast app—it really helps more people discover the show.

Fully Modulated is not affiliated with or endorsed by any station, media company, or network. All opinions are solely my own.

Episode Transcript

Tyl (00:24):
Tyler
And let's be real for a second.
If you grew grew up listeningto radio, you probably think AM
is the crackly buzz-filled bandthat you know plays talk shows,
ball games, late night weatherwarnings, maybe uh a preacher on

(00:45):
a Sunday morning.
But here's the you know, here'shere's what happened to me.
I'm cruising through YouTubeone night, not really searching
for anything in particular, youknow, that classic YouTube
rabbit hole.
And I get a recommendation forthis clip.
1240 K E V A and AM stereo outof Eveston, Wyoming.

(01:12):
Honestly, I'm expecting sometypical AM fuzz.
Instead, I hear music thatmakes me sit up straight.
But it's not just clear, it'spunchy and full and almost like
listening to FM.
So, you know, of course.
I clicked another uh demo videoand this one showing off C-QUAM

(01:37):
AM stereo.
Suddenly I'm hearing, you know,stereo coming off of AM radio.
And it's it it's a wild it'swild in the best possible way.
So, of course, I get curious.
Why does this sound so good?
And why in the world doesn't AMstereo exist everywhere?

(02:02):
That kicks off an all-nightdeep dive.
I swear I stayed up to like1.30 in the morning.
A real trip into radio's weirdhistory, technical twist, and
missed opportunities for AMstereo.
And, you know, at this point,AM Stereo was mostly history.

(02:35):
Nobody around me had it.
Sometimes you'd see folks inradio forums swap stories about
how great it was.
Like a legend, a unicorn youheard about, but you know, never
caught yourself.
But after those YouTube clips,I wanted to know what the deal
was.
Why wasn't this the standardeverywhere?

(02:58):
And what happened to it?
So here's the basics.
AM and FM radio are like twototally different ways of
getting sound from the stationto your speakers.
AM or amplitude modulation isthe old school method.

(03:19):
FM stands for frequencymodulation.
That's what you tune in for thebig sound, stereo music, and
minimal static.
While, you know, FM could putmusic in stereo from early on,
AM got stuck with mono fordecades.
That meant one channel, onespeaker, fine for voices and

(03:44):
sports, but kind of bland ifyou're a music fan.
And way back in the 1950s,engineers already knew how to
make AM stereo work.
Picture it as the differencebetween listening to a band play
live in front of you, instereo, versus hearing it from

(04:05):
just one tiny speaker, often uhdistance, being mono.
Problem was the people incharge didn't want AM stations
to get any stronger.
Especially since FM was stillthe underdog.
So adding stereo to AM gotshelved.

(04:27):
Everybody focused on getting FMreceivers in cars, pushing FM
stereo at home, and the musicaudience slowly slid away from
AM.
But in the early 70s, FM wasgetting trendy.
The record stores and the carjunkyards were full of cassette

(04:48):
decks and eight-tracks, youknow, geared to FM.
The whole world wanted music instereo, not flat old school
mono.
AM kept playing music for awhile, but was losing the battle
for younger ears.
FM became the spot for rock,pop, hip-hop, country.

(05:11):
It was sound that, you know,quote unquote, filled the room.
Companies like Motorola,Harris, Magnavox, Khan weren't
ready to give up the fight justyet.
Each built their own version ofa stereo system for AM.
Motorola C-QUAM, compatiblequad rat what is it, quad rature

(05:38):
amplitude stereo I'm screwingthat up.
Quadrature.
Basically, that won thepopularity contest over time.
Put simply, C-QUAM was a smartway of combining both left and
right channels into a regular AMsignal.

(05:59):
So anyone with one of thosefancy stereo radios could hear
real stereo, and the folks withthe old radios didn't get left
out, sort of being backwardscompatible.
All the cool stereo stuff hidin a second layer, invisible
unless you had the right kind ofradio.

(06:19):
Sort of like today's HD radio.
It's kind of like also, youknow, sending uh a secret
handshake along with the regularwave.
You pick up both, but if yourradio is old school, you just
get the regular handshake.
Obviously, this all soundspretty clever, right?

(06:48):
Until you hear it, I mean, it'sastonishing.
Each company wanted theirsystem to be the one system.
The FCC, after years oftesting, picked Magnavox as
their winner in the night in uhin the early 80s.
That made everyone elsefurious, of course.

(07:10):
Lawsuits cranked up.
A few months later, the FCCthrew up their hands and said,
you know what, screw it, let themarket figure this out.
Well, the market mostly justgot confused.
Different stations went withdifferent tech.
Car companies built radios thatonly worked with some systems,

(07:32):
and listeners kept hearing monoor got no stereo at all,
depending on their gear.
Dealers stopped stocking thefancy stereo models.
By the time Motorola C-QUAMfinally became the official US
standard in 1993, most AM musicstations had switched to talk,

(07:54):
news, or sports anyway, so itdidn't really matter.
But let's get hands-on for asecond.
What did it take for a radiostation to actually put out AM
stereo?
Enter the Harris AMS G1 exciter.

(08:15):
No, not the sci-fi kind ofexciter.
This was a simple metal boxthat plugged into the main
broadcast gear at the radiostation.
Its job was to take music andsend that out in a special
stereo format using Motorola'sC-QUAM system.

(08:35):
In other words, you could treatit like a magic box that
flipped your station from anordinary motto signal to full-on
stereo.
If your listeners owned theright kind of radio, they would
get AM stereo.
Engineers love these thingsbecause there was no rebuilding

(08:57):
the studio from scratch.
You'd run a couple of wires,turn a dial or two, and suddenly
your old AM music show soundedbigger and richer than ever.
The Harris box handled all thetricky bits, making sure the
signal stayed clean, separatingleft and right sounds, and
dealing with any weird quirks inthe transmission system.

(09:20):
It it worked with all kinds ofmusic, talk and anything you
tossed at it.
If a station wanted to trystereo for a late night show and
I don't know, stick to mono fornews in the morning, it could
just tap a button.
It was that simple.
The Harris AMS G1 and MotorolaC-QUAM combo, it was kind of the

(09:44):
dream t the dream team.
You could go toe-to-toe withany FM station on sound quality,
especially if your audience wasclose enough for a strong
signal.
But here's what happened.
While this tech could havehelped AM keep music relevant,
of course it showed up a littletoo late.

(10:07):
The years of confusion overwhich system to use mixed with
all those format switches meantmost music fans were, you know,
they were already long gone.
Even car companies dropped AMstereo on their radios.
Since so few buyers asked forit and most stations had
switched things up anyways.

(10:28):
The problem wasn't the sound,it was just bad timing.
Now, here's the part thatnobody talks about.
The limits on what AM can do.
The teeny tiny sound, lessbass, more static, those are
mostly because of rules, notwhat the equipment can do.

(10:52):
If you've got a station with aHarris exciter, a solid
transmitter, and nobody elsecrowding the same frequency, AM
stereo can blow you away.
Seriously, it it competes neckand neck with FM, in my opinion.
Stereo on AM isn't just goodfor AM, it's good, period.

(11:14):
That's why those old demosonline sound so surprising.
So, you know, why don't we hearmore AM stereo today?
Well, there's a few diehardstations still playing music in
stereo.
You'd need the right kind oftuner, not just any old radio.

(11:35):
The gear's rare and sometimestakes a little hunting to find.
But when you do, it's a treat.
Michael J.
Richard, the guy from KEVA, youknow, that station I mentioned
earlier, dug up some old C-QUAMgear and got permission to hook
it up to a station.
For about a decade, they ranoldies and rock tunes in stereo,

(12:00):
living proof that AM didn'thave to be second class.
The sound was good enough tograb the FM listeners.
You know, if they gave it achance, obviously.
Around the world, Canada,Australia, Japan, there were
still stations doing AM stereo,sometimes even using upgraded

(12:22):
versions of the same oldhardware.
A few newer high-end receiverscan decode it.
But here AM is well, you know,mostly talk, sports, and news at
this point.
Let's uh let's step outside thestudio for a second.

(12:42):
Imagine you're somebodylistening in your car.
You're used to AMB for weatherand sports.
Then one night you catch astation playing classic rock and
it sounds way better than usual.
Maybe you switch the radio overto stereo mode, and you s and
and you know, all of a sudden,that sound make you know, the

(13:05):
song just pops.
Like you're hearing live musicin the front seat.
Most people never got to hearwhat AM stereo could do, and
that's a real shame.
I've never heard it myself inperson other than those demo
videos, you know, I found onYouTube.
Those YouTube clips aren't justrelics for audio nerds.

(13:28):
They're a snapshot of what AMcould have been if all the right
pieces lined up.
Smart engineers, better timing,and a little luck from the FCC.
It was a road not taken, mostlybecause nobody could agree on
who could uh who should lead theway.
Today, AM stereo is a hiddentreat.

(13:52):
Something you search out likevinyl collectors hunt for rare
LPs.
It isn't just nostalgia.
Some hobbyists still run localAM stereo stations, and if
you're lucky enough to livenearby, you'll catch that music
alive and full, and not thatthin scratchy AM sound that we

(14:15):
typically hear.
And one more one more fun factfor you those old Harris AMS G1
exciters could even be set up sothat depending on the time of
day, daytime versus nighttimesettings, your stereo sounded
clean with less noise even aftersunset.

(14:36):
It had clever circuits thatkept music sharp and kept the
signal under control.
So, what do we take from this?
Radio changes because peoplechange.
Tech grows, formats flip,companies jockey for, you know,
their slice of the pie.

(14:57):
But every now and then there'sa solution that's genuinely
great, even if it doesn't catchon.
AM Stereo and gear like theHarris AMS G1 are those kinds of
ideas.
If you're into old school orjust want to hear something

(15:20):
different, try to find a stationor a YouTube demo.
There's nothing quite likegetting that full sweep of a
favorite song spilling out overa band most folks thought was
long out of style.
Alright, so let's wrap it upwith a few thoughts.

(15:41):
AM Stereo might uh never make afull comeback, but it's one of
those things that proves radiois always surprising.
Whether you're spinning thedial just to see what's on or
geeking out with old gear inyour garage, there's always
something worth listening for.
Thanks for sticking around forthis expanded episode of Fully

(16:04):
Modulated.
If you like the stories, wantto support what I'm doing, tap
the the uh the follow button onApple Podcasts or Spotify.
Every rating or review helps.
Got a radio memory yourself orjust want to nerd out over old
uh AM Tech, email me, Tyler atFully Modulated.com.

(16:24):
You can find me at FullyModulated on Facebook and at
Fully Modulated Pod onInstagram.
This is Fully Modulated wherethe stories are infinite and the
static is never just noise.
Go see what's on your AM dial.
You never know what gems mightbe waiting.
Hey, quick heads up from afellow phone bill hater.

(16:52):
If you're tired of paying toomuch for your cell service,
check out Visible Wireless.
It's the real deal.
Unlimited data, talk, text, andyes, even Hotspot, all running
on Verizon's 5G and 4G network.
Plan start at $25 a month withtaxes and fees already included,

(17:13):
no surprises, no games.
Plus, you can bring your ownphone and your phone number, or
maybe grab a new one if youwant.
Super simple to sign up, andyou can even activate via eSim
if your device is compatible.
Now, here's the kicker.
If you use my special link,visible.fulymodulated.com, when

(17:36):
you join, you'll get 20 bucksoff your first month, and I'll
get 20 bucks off.
It's a total win-win.
Now, this isn't some sponsoredthing.
It's just me sharing a hookup,my own referral code for you.
Whether you're sick of bigwireless or you just want to
save some cash without losingcoverage, visible makes it easy.

(17:59):
Unlimited everything.
No contracts and zero hiddenfees.
Seriously, why would you paymore?
Visible.fulymodulated.com andstart saving today.