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The tragic birth of FM radio (2006) (damninteresting.com)
234 points by ineedasername 6 days ago | hide | past | favorite | 65 comments





While reading through the comments on that article, I was reminded of my Dad's own journey through the years as a radio engineer.

When I was growing up, he was the market engineering director for one of the two or three local FM conglomerates, and through the past 30 years or so, they kept getting gobbled up by larger corporations until probably 90% of the AM/FM radio audience was owned by either Clear Channel or CBS-then-Entercom-now-Audacy.

These groups also cut back substantially not only on local radio talent (there used to be shows through the day run by local DJs, now you're lucky to get a morning show and maybe an afternoon drive show), but also on the radio engineers deployed to the stations.

A lot is due to automation and ease of IP audio (and popularity of alternative formats like YouTube and Podcasts), but it's a bit of a sad, slow death of something I remember more fondly as a kid.

I recently had my Dad take me on a tour of a 'megawatt' (ERP) FM tower site in St. Louis (we posted a YouTube video of it) and it's incredible the engineering that goes into getting a signal (in the case of this site, 10 signals) into an FM antenna system 300m above the earth!


>it's incredible the engineering that goes into getting a signal (in the case of this site, 10 signals) into an FM antenna system 300m above the earth!

this is what always amazed me. we used to drive by/through the local antenna farm in my area, and it always impressed me as a kid that these towers was where the radio/tv signals originated. driving by, you could see the bases of some of them were on a single point of an inverted pyramid which revealed the importance of the guide wires. these were the first structures that i understood to be designed to move. then learning stories of the power of the signal, the amount of electricity to create that power, the fact that the AM signals could change their wattage at night to be more powerful, that video was an AM signal with the audio being FM all multiplexed together.

then there was the time that a military jet clipped the guide wires forcing the 2 occupants to eject and causing the station on that tower to go off the air. or the much more gruesome time a local teenager climbed one of the smaller towers, thinking he could recreate an action movie scene, attempted to slide down the guide wires. the attempt was not successful as it sliced off his fingers causing him to free fall catching a lower wire which created 2 halves of him. in case anyone thinks of trying this, don't.

after all of that, wound up becoming a video engineer.


FYI, they're guy-wires not guide wires.

https://en.m.wikipedia.org/wiki/Guy-wire


yes, sorry, but you're clearly "not from around these parts".

https://en.wikipedia.org/wiki/Guide_wire

•Alternate spelling to guy-wire


But it doesn't make sense to call it a "guide wire", it's not "guiding" anything.

It is however guying the tower. guy; 3rd person present: guys; past tense: guyed; past participle: guyed; gerund or present participle: guying

secure with a line or lines. "it was set on concrete footings and guyed with steel cable"


https://www.etymonline.com/word/guy

> guy (n.1) "small rope, chain, wire," 1620s, nautical; earlier "leader" (mid-14c.), from Old French guie "a guide,"...

pretty wild what circles language may run in.


That is interesting to see that connection, thanks for sharing!

Maybe we should just call them pedant wires?

Man on internet tries to correct things outside his control, news at 11.

Today, a random person on the internet took it upon themselves to let the rest of the internet know that someone was doing something they did not like. Themselves, in all things being perfect, decided it was high time to correct the pedantic use of a word in a way that differs from their personal use. In other news, the internet yawned, and went about its day.


I'm just trying to share that the vast majority of people involved in towers would call them guy wires and not guide wires. Feel free to use whatever word you want to describe them, call them party lines or whippy clips or pedant wires or whatever you wish to call them. The people involved in actually running them will still call them guy wires in the end.

I mean, just do a quick Google image search. Search "guide wire" and then "guy wire". Which one returns images of towers?

I'm sorry you took offense to me sharing information with you. I definitely didn't intend to make you upset by letting you know those cables are almost universally called a different term.


Linguistically it’s easy to see why people would blur the line from cables that did guide something.

People use cables or ropes to guide long poles or similar structures into position and then tie them down for stability. Cranes of are of course easier, but not always available such as when replacing a sailing ships mast at sea.

Guy wires are often used similarly if for example wind loads are an issue during construction their tension need to be adjusted appropriately.


I suppose that makes sense if the wires are plotting to blow up antennas with gunpowder.

Enough people say it wrong it eventually becomes right. There's nothing definitive about language except for usage...

> Enough people say it wrong it eventually becomes right. There's nothing definitive about language except for usage...

This is a view that is common among English speakers. Among many German native speakers it is instead common to love to analyze words and tell why some word is wrong even if it is actually in common use sometimes for decades.


The noise these wires make when struck became the sound of blasters in Star Wars.

> could see the bases of some of them were on a single point of an inverted pyramid

I was under the impression these towers were AM because such a long wavelength is needed for AM radio stations that the whole tower is the antenna, with an insulator between the point of the inverter pyramid and the ground.

FM towers are not like this; the wavelength is much shorter and the tower is not part of the antenna. The antenna is a short element at the top insulated from the tower.

Happy to be corrected.


FM antennas are indeed placed as high up as possible on these towers, but the tower itself, being a guyed model and not freestanding, does come down to a "ball and socket" joint at the bottom, which allows the tower to move around slightly under the tremendous pressure of the guy wires yanking it down to earth.

Apparently there's a deep 25'x25' slab of concrete underneath that holds the socket the tower rests on.


AM stations generally reduce their power at night, rather than increase it.

Yeah that was later because the power stations caused too much interference. The reach of medium wave increases at night and you get some local interference of far stations. They mitigated that by raising their local power causing even more interference. FCC stopped that :)

I saw that video the other day - it was seriously amazing! That you for sharing it! I shared it around with a bunch of people who I figured would find it interesting as well. I would love to tour a facility like that one day, though chances are slim the stars will align in such a way. Who knows, maybe one day! haha :)

Small world, the youtube algorithm put that video in front of me the other day, enjoy it a lot.

I once worked for RCA and I briefly met David Sarnoff during the opening of a new RCA plant in Australia. I liked working for company and I found the electronics work I was doing there interesting—in fact it was one of the best jobs I've ever had. I was later involved with the introduction of FM into Australia but that's a separate story.

That said, David Sarnoff was a nasty opportunistic litigious man and frankly the way he treated Armstrong, Philo Farnsworth and others was despicable.


FCC’s move of FM frequencies influenced by Sarnoff really messed up with Armstrong, making his stations obsolete. This is also why there is no Channel 1 on TV in the US: https://en.wikipedia.org/wiki/Channel_1_(North_American_TV)

Another inventor Sarnoff stole from was Philo Farnsworth (https://en.wikipedia.org/wiki/Philo_Farnsworth). He didn’t kill himself like Armstrong but was broke and forgotten when he died in 1971.


Utah just decided to switch his statue out from the National Statuary hall in the US capitol but there’s a lot of consternation over it. It might be back in 10 years.

It's an indictment against the U.S. legal system, really. You'd think folks would be chagrined enough to fix it after 50 or 100 years.....

This article was written by a friend of mine, he passed away unexpectedly back in 2011. It's a shame, he was a swell fellow and had so many more stories to tell. We miss him.

It's a good article. So how do we keep things like it around after the author is gone?

For Damn Interesting (the site where this article originated), our approach is to offer our catalog as a DRM-free eBook, downloadable as a reward for certain donations (we are ad-free and user-supported). As a consequence, there are theoretically thousands of copies of this article (and our others) on our readers’ devices.

There are some technical inaccuracies in this article.

While Sarnoff did try to kill FM as a threat (more NIH than anything) The move to 88-108 had some other good technical reasons - the higher frequency is less prone to skip, multipath, and tropospheric ducting. When the band opens on 6m (where the original band was) stations hundreds of miles away can swamp local traffic. Because Television isnt subject to the capture effect, there are less issues with it with analog TV. The interference of remote stations at the frequency it happens on low band VHF, would have sunk FM in the long term.

AM Radio Bandwidth. The original allocated channel bandwidth for AM allowed closer to 11-12kc of audio bandpass, with 8-10 being pretty common - the quality was more a function of how the lines feeding the network traffic to the station and the station to transmitter link were conditioned, and often well into the 70's the STL link was a leased conditioned line from the telco.

I do not disagree that RCA used its market position as holder of most of the radio related patents to shut out Armstrong, and it was/is despicable - but not all of the bad thind that happened were just malicious to be malicious.


This would make a very good film for cinema/TV. It’s got many things from the checklist: technology, legal battles, pre-war era style, authenticity, personal struggle and so many that would make for a good scenario and paired with a couple of good actors, for sure it would be great.


“He built an experimental station and 410-foot tower at a cost of $300,000 in Alpine, New Jersey.”

Assuming this was done in 1938, this would cost the equivalent of $5.6 million today. And it was made obsolete by the frequency change just 7 years later.


And the spectrum RCA wanted between 42 and 50 MHz for television was only reserved. It was removed from the allocation table before it was ever used.

With that said, 88 to 108 MHz fits a lot more stations than 42 to 50 MHz would have. The 42-50 would have had to expand somehow.


The 200 khz bandwidth of an FM broadcast signal might have been narrowed to allocate more channels. It is wide enough to carry all that additional info such as the stereo signal (not much of an issue in the 1940's, as nobody had stereo speakers or amplifiers at home), and the additional services (e.g. talking books for the blind, foreign language broadcasts, etc that have been multiplexed on top of the FM signal during the decades since). Now it also can carry the hierarchical digital (some of the comments to the original article apparently accept hierarchical-digital as high-definition, which it isn't) signals. The quality of music received by FM now is not so good as it used to be before all that other stuff started freeloading on the carrier. Most FM broadcast tuners and receivers are supposed to suppress the unwanted content by approximately 70 to 80 db. I don't know if the receivers go out of spec over the years, but when listening to classical music broadcasts medium loud, I often hear a soft garbled chatter during the quiet passages and silences between movements. From my POV, FM is fine for casual music listening but dead as a preferred medium for high-fidelity music. I am too discouraged by the poor S/N ratio that I now hear on FM to dare to spend much for for a better receiver that may not be significantly superior.

They could have used 100kHz spacing in 42-50 MHz instead of the 200kHz spacing they use for 88-108 MHz. Wouldn't have sounded quite as good most likely, but still a substantial improvement from AM's 10 kHz channels.

Oh, I agree. Definitely an improvement over AM. With the 100kHz spacing, it would still only fit about 80% of the channels we currently have.

If they stuck with 42-50 MHz, they'd probably have to be creative, like have New York City use horizontal polarization and Philadelphia use vertical polarization (although now we know that doesn't make a huge reduction of interference).

If they expanded it downward, it would touch what's now the high end of the shortwave bands. Might have been some interesting propagation. Sometimes when the conditions are right, a 25 MHz signal can travel the globe during the daytime.


A 42-50 MHz FM band would have been an interference nightmare. During the summer months, Sporadic E propagation is very prevalent on those frequencies (with high signal strengths). And during large sunspot cycles, regular F2 layer propagation is possible during the fall and spring months.

During the peak of sunspot cycle 22 in 1989-91, a great F2 layer propagation indicator here on the west coast US was New Zealand TV channel 1 audio on 50.75 MHz (+/- 10 kHz). If you could hear the wideband FM audio on 50.75 MHz, it was almost guaranteed you could make a ham radio contact with New Zealand at 50.110 MHz.


That move destroyed the fledgling network. Armstrongs network was an eclectic bunch of radio stations, talk radio etc. The new fm band was at a higher frequency and equipment was more expensive so it drove the Indy operators out of business. Radio became a Cesspool of corporate radio stations pumping out music and ads.

AM talk radio revived that old spirit in the 1990s.

We see similar things happening nowadays. After the corporate takeover of Twitter, the old guard has been dispersed. The Twitter of years past will be remembered as a creative and diverse place…going forward it will not be the same.


Alpine Tower is so recognizable that it’s one of just a handful of visual reporting points for helo and low-flying fixed wing traffic transiting the Hudson River. (Verrazano Bridge, Statue of Liberty, Clock, Intrepid Aircraft Carrier, George Washington Bridge, and Alpine Tower.)

A slightly comical animated look at Edwin Armstrong's invention of FM radio can be seen as part of Tim Hunkin's "The Secret Life of the Radio": https://youtu.be/LMxate9gegg?t=779

It's split into two parts, with the second part later in the same video, here: https://youtu.be/LMxate9gegg?t=1350


The Secret Life of... series really is wonderful (and he has remastered versions on YouTube).

I ran across the fax machine episode on YouTube years ago and it is still one of my favorite half hours of television.

Any link to a master playlist?

YouTube search.. leaves a bit to be desired these days.



FM radio really is very good quality even still, it must have been spectacular back in the 30s. In fact, it's so good it's stymied the uptake of DAB radio, at least in the UK. Digital radio in fact is often worse as it is so compressed. Funny, they are trying the same 'stealing the frequency allocation' trick again, but delayed for now.

https://www.theregister.com/2020/07/03/analogue_commercial_r...


Am I reading this right: the UK government is making an organized effort to kill AM and FM radio stations, to free up their spectrum for... what exactly?

Not only in the UK. Norway too, and probably some other European countries. No more national wide FM stations in Norway (it's still possible to have a local FM station - for how long I don't know). There's some worthless talk about re-using the spectrum for 5G or whatever. So now there's DAB. I don't listen to radio anymore.

" to free up their spectrum for... what exactly?"

Whatever/whoever comes with the most amount of £££. Same old, same old.


This article reminded me about current changes related to EU's Unified Patent Court (UPC), discussed at https://news.ycombinator.com/item?id=33630823.

JUVE Patent website presents comments from UPC on the subject: https://www.juve-patent.com/news-and-stories/people-and-busi...

Edit: fixed the second link attribution to JUVE Patent, and removed speculation regarding trivialization of the issue by UPC.


> Through the years Armstrong’s widow would bring twenty-one patent infringement suits against many companies, including RCA. She eventually won a little over $10 million in damages.

Insert "(nearly a third of a billion in today's dollars)" there.

I don't know the actual figure.


The RCA suit was settled for $1 million in 1954. Assuming the other suits were completed around that time this would be $93 billion dollars today!

Hmmm my calculations show 1000% inflation over that time and $110m.

assuming he means "million" not "billion" you two are pretty close.

The Damn Interesting podcast is amazing please subscribe. They release not often and the long-form stories are super interesting and well-produced.

Also I like Damn Interesting Week podcast that discusses fun news articles, they have so much fun with them.


21 years before the invention of FM radio, the electric car had peaked in production. By 1933 they had gone out of fashion, and 2 years later effectively disappeared from roads.

Something that could have been spelled out more clearly is they NTSC uses FM for audio.

Which is why the audio of VHF Channel 6 (audio carrier on 87.75 MHz) is clearly audible on an analog-tuned FM radio. I remember my mom keeping a radio in the bathroom for listening to KWTX for the morning news and the first part of the Today Show as she got ready. She thought they had intentionally rebroadcast the audio on the radio.

This of course has gone away with digital TV.


Not quite gone away yet. There are 13 experimental channel 6 stations using ATSC 3.0 to continue sending an analog FM carrier on 87.75 MHz. ATSC 3.0 has reduced bandwidth options of 5.752, 5.671, 5.590 and 5.509 MHz. The 5.509 MHz option is used and the OFDM signal is shifted down approximately 200 kHz, leaving enough room for the FM carrier and modulation at 87.75 MHz.

The stations are WNYZ-LD New York City, KZNO-LD Los Angeles, WRME-LD Chicago, KBFW-LD Dallas/Fort Worth, KBKF-LD San Jose, WTBS-LD Atlanta, WDCN-LD Washington DC, KEFM-LD Sacramento, WEYS-LD Miami, KXDP-LD Denver, KGHD-LD Las Vegas, KMCF-LD Fresno, and WPGF-LD Memphis.

The FCC has issued an NPRM to decide if these stations will continue.

https://docs.fcc.gov/public/attachments/FCC-22-40A1.pdf


Ken Burns retells this story masterfully in "Empire Of The Air" which should be considered mandatory watching for anyone with an interest in this stuff.

Remember HD radio? I'm amazed how little adoption that still has. They got the radio stations to buy in which should've been the hard part. If it was like any other technology it should be built into the FM tuner chips for basically no cost by this point. Maybe the patent licensing is really expensive? The patents can expire just in time for nobody to care.

Perhaps we’re an outlier here in the Minneapolis/St. Paul MN area - a strong majority of FM stations here broadcast in HD. Most have at least one, if not two other HD broadcast streams in addition to their main one.

I tend to listen a lot to the HD2+ streams, as advertisers seem to not be interested in paying for ad spots there (which I guess could be indicative of poor adoption, at least beyond the main HD streams).


Another theory: SiriusXM bribed carmakers to install satellite radio receivers and to not install HD Radio. The first part is assumed given how Satellite radio receivers are (were?) installed close to universally, even in pretty basic cars. The second is a pretty plausible extension of that.

I’ve had it in the car for seven years I think. Was late then. Looked into getting it in the house but it was quite difficult for some reason.

I just finished reading The Master Switch by Tim Wu. It includes the history of broadcasting including why it took so long for FM radio to succeed.

According to him, Sarnoff and Armstrong were friends at some point and RCA financed the development of FM radio initially although they just wanted a more efficient AM network.


Edwin Howard Armstrong, like "The Man Who Fell to Earth", is one of those people who not only presented the world with an idea seemingly ahead of its time, but did so repeatedly.

Perhaps after he traveled back in time our future government(s) outlawed that sort of thing.


Someone need to add this to Sarnoff wikipedia page. https://en.m.wikipedia.org/wiki/David_Sarnoff



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