Armstrong: the Tragic History and Physics of FM Radio
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- Опубликовано: 5 авг 2018
- How Howard Armstrong created and detected frequency modulation (FM) radio and how it was so impressive that it actually caused his downfall!
Some links:
• Video
Very good video but, unfortunately, the methods that they described were not used by Armstrong. Still A+
• Video
OK video, not as detailed as the 1944 one.
The background music was from Kim Nalley and the "New Orleans Hop Scop Blues" which is by Jimmy Noone.
The theme song is by Kim Nalley and is a cover of "Electricity Electricity" from Schoolhouse Rock :)
• Electricity, Electric... 
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A simple and easy to understand explanation. Thank you! Edwin Howard Armstrong has always been one of my favorite inventors and inspirations. And what Sarnoff did to him was unforgivable!
I got interested in electronics and electromagnetic waves by discovering my grandad’s 1922-23 radio textbooks and some old radios in the attic, and ended up in a related career. The history was part of the fascination. You’ve done a great job of presenting it.
Very cool.
Armstrong invented the receiver regenenative, heterodyne and the superheterodyne. He is the great radio inventor. Chapeau
There is a radio tower called the Armstrong Tower, in northern NJ, across from NYC. First FM broadcast there.
@@robertewalt7789 Alpine, NJ, isn't it?
You do realize that "chapeau" is French for "hat?"
@investorguy, yes the Armstrong Tower is in Alpine, just off 9W, not far from the Palisades Parkway.
@@ApartmentKing66 He meant Chappaquiddick & something about a Kennedy getting away with a woman drowning in a car accident he caused by driving drunk because he did nothing to help or save her.
Great work, Kathy! Thanks for bringing us this great history of FM radio. Back when I was a flight instructor near NYC, we used the "Alpine Tower" as a visual landmark for flying up and down the Hudson. I never knew that tower's connection to FM broadcasting.
Armstrong did so much for us who depend on radio.
In order to get enough frequency deviation, Armstrong not only multiplied a low frequency signal many times, he took the resulting high frequency signal and heterodyned it back down so he could multiply it many more times, then he once again heterodyned it back down and multipiled it more. All of this multiplication finally gave him enough deviation.
When I started high school around 1970, our school started an FM radio station WCNE, which is now community station WOBO. Our first transmitter was a CCA FM10D, which used a low frequency crystal oscillator driving phase modulator. Phase shift and frequency shift are essentially similar types of modulation. In order to get enough deviation for broadcast, the FM10D had several multiplier stages, similar to Armstrong's Columbia prototype.
In fact, the de-emphasis network in the FM receiver, integrates the audio waveform above the knee of the de-emphasis curve with 6 dB per octave, essentially making high frequency audio compatible with a phase modulator. A phase modulated FM transmitter has what is called a pre-distortion network to adjust low frequency audio to be compatible with the de-emphasis curve. Note that the purpose of emphasis is to reduce high frequency noise, which is caused by the equal energy-per-octave response of the ear. It is just that de-emphasis can do double duty, both reducing the HF noise and integrating phase modulation. It seems this subtlety is missed by the amateur radio examination which wrongly asserts that the PURPOSE of de-emphasis is make an FM receiver compatible with a phase modulator; this is a byproduct, not the purpose.
It is somewhat complex to generate a stereo signal using frequency multipliers, so as stereo took hold in the late 1960s, Gates developed the TE-3 direct FM stereo exciter. The problem was that a crystal oscillator could not be "pulled" far enough for wideband modulation, so the TE-3 had a complicated phase-locked-loop automatic frequency control system to loosely lock the FM oscillator to a crystal reference. The problem was that certain audio, particularly heavy bass, would cause the AFC to unlock and the station would drift. Disco music of the mid and late 1970s was the death of the TE-3. As the 1980s were getting started, Harris (who had bought Gates) came up with the MS-15 exciter, which was a direct FM unit with a much improved AFC system. My experience with the TE-3 was at WMRI and the MS-15 was at WKHY.
So far as AM, broadcast could and did have good fidelity. When I worked at WBAA, our 5 kW Collins 21A transmitter had audio frequency response only 2 dB down at 15 kHz, which I measured. I had 2 different EE professors at Purdue tell me that AM broadcast stations must limit their audio to 5 kHz, which is completely incorrect. But a lot of people apparently believe this myth. In the early 1980s, the FCC started requiring stations to limit audio to 10 kHz (the NRSC emissions mask) so they could overpopulate the broadcast band. Wideband (10 kHz) c-quam stereo AM can sound amazingly good, but as time goes on modern electrical devices are raising the noise floor so that AM reception in cities may be too noisy. A couple years ago, during an extended power outage, I did some amazing AM broadcast DXing!
I have found it sad that few people working in broadcast know the names Fessenden and Armstrong, radio pioneers who created their industry.
Thanks for that interesting comment. Wd4cxq
In 1979, when I took over as Technical Director of our college station, they had recently purchased a new FM transmitter, antenna, and stereo generator. (Also, Emergency Broadcast device, mixer, mics and turntables.) Previously, the station had been 10W (ERP 10W from a monopole). The TD before me had installed the audio equipment, the EBS device and the Orban stereo generator.
My first major task was the technical portion a new license application for the 100W transmitter and 1.64 gain antenna. (They had spent the entire grant on hardware, and had nothing left to pay professionals to perform the license application. I _did_ get -a little- help from an alumnus EE to do setup and measuring/verifying the equipment performance. He worked for a company that let him borrow test & measurement equipment - he would drive 250 miles each way to help me on a few weekends.)
The Orban Optimod stereo generator seemed magical - easy to configure, compression that did not intrude (though it would allow one to crank up the compression until it had near-zero dynamic range), and our audio quality was better than the commercial FM stations available locally. (They caught up. One of the broadcast engineers came an asked us about it, read the manuals and played with the settings...then got his station to go Optimod, too.)
Others installed the new antenna before it was licensed. [I just went back and edited the station name out of the text above, to protect the innocent.]
In High School, I read a biography of E. Howard Armstrong. Starting during Jr. High, I also constructed and experimented with my own outdoor antenna to DX AM at night.
This is truly a story with a tragic ending (very sadly) and not click bate like so many other RUclips posts. Thank you for the history.
bait
Howard Armstrong was a genius! His demise was tragic. Rest in peace Howard. Kathy nice job!!!!!!
Your series of videos is really great. Please keep up the good work! Your subject may not appeal to everyone (I wish it did), but I am sure there is a small subset of viewers that really appreciate the work you have put into these videos!
It appeals to me - a lifetime with electronics and a history buff - win-win
Well that was way more interesting than I thought it would be. Thank you very much. Interesting how complex the original discriminator was compared to the 60's when I got into the game. It also demonstrated what was (is) so seriously wrong with the US patent system. Sarnoff shouldn't have only been fined, he should have been jailed along with all of his lying engineers and anyone else that colluded.
Meanwhile, at around the same time, the Wright Brothers were busy using their patent on controlled flight to suppress all competition in the US aviation industry, letting the Europeans get an early lead.
@@lawrencedoliveiro9104 monopolies at their most efficient! :/
@etmax1, no Sarnoff should've been imprisoned and buried under the prison.
The problem is really corruption and that rich power hungry psychopaths is running the world and has the power, it is now 1000 times worse then ever...
A very clear example that intelligence without wisdom can be a deadly weapon.
Today this is visible all over the place...
Yes, Armstrong's method was far more complex than needed. This often happens with inventions. The "ratio detector" seems very obvious to us today.
Very good video, Kathy! Major Armstrong truly WAS the "father" of radio, NOT de Forest. Armstrong took de Forest's Audion and actually figured out how it worked and why, de Forest really not having a clue as to its operation. Armstrong then developed circuitry which would amplify radio signals and also generate them. He went on and invented the regenerative, super-regenerative and superheterodyne circuitry, circuits which we still use today in all AM & FM radios, in television and in cell phones. Armstrong also, as this video explains, invented wide-band FM radio, which was truly "high fidelity" and also FM multiplexing. All this is explained in PBS' documentary "Empire of the Air: The Men Who Made Radio."
As an amateur radio (ham radio) operator, for the past three years, I have put on a special event, using my ham radio station at my home, in honor of Major Armstrong. I have a special FCC call sign assigned to me and I try to make it a 3-day affair. I use Morse Code only and try to work as many other hams here in the USA and around the world as possible. This is my on-going effort to honor Major Edwin Howard Armstrong. Truly a great man! Thank you.
Great series. RUclips should finally boost these videos, they are very valuable, as they tie together good explanation of how things work based on our knowledge of natural laws, the people who discovered them, and economy and politics together in a complete image. Everybody can learn something new from these videos. Truly great work. Hope your channel goes viral, it deserves it. The quality, precision and a good narrative communicated pleasantly and simply (yet not oversimplyfied) of your videos beats all those clickbait hype "tech", quantity content on RUclips. Other videos will be forgotten by history, but these are timeless.
@@sjb3460 I do not watch shorts at all. I hate vertical video and watch on PCs and in the rare cases when I watch on my phone, I always rotate it to its side. Shorts are perfect for the short attention span of the audience and RUclips makes it even worse and creates more and more "zombies" with an attention span of 30 seconds or less, just to forget what they just saw, as it gives literally zero new and memorable knowledge in the vast majority of cases. I really hate this trend.
@@erikziak1249 jesi naš?Skip,if you dont understand,you very well descibe me,i lost probably hour of valuable time watching shorts,literally forgotting things i saw.
@@trofaznimotor901 Kathy má oveľa kvalitnejší content ako priblblé shorts, odporúčam. A niečo aj o polyfáze, ideálne pre trojfázový motor.
Thank you so much for such an informative video Kathy. You were able to include so much important information in just 12 min. For me, Armstrong is the greatest American engineer.
Thank you for that great explanation. I still have the 1950's FM radio Tech Manual I filched from the army when I was working in communications in Korea. Your explanation makes a lot more sense than theirs did to someone new to the field.
Your channel is great. I love the straightforward and clear explanations of some very difficult material. You will probably never make as much as perhaps you should but from some of us who have lived through a lot of this, you have a great channel.
you are exactly doing the type of the program that I love most: history of electronics..
Ok, this is an instant sub. I'm a little upset RUclips's been sleeping on this channel in my reccs. Fantastic job, Kathy!
Wow, what a sad story! I wasn't expecting such tragic ending.
Thank you for your great videos!
Well done for making the explanation of FM and Armstrong's Phase modulator, and his demise that was so tragic.
THANKS for this, Armstrong is a hero of mine and it's always satisfying to see his story told as it deserves..
This is my new favorite channel. Thank you so much for making these videos.
srvr1007 thank you so much for thanking me so much (if that isn’t too meta)
SHOE! My new fav chan too! Kathy, you're brilliant. I hope to get fully caught up on your series here soon, and hopefully you've done a video sharing your own background. I'd love to hear the story on how you got so knowledgeable on the Big E.
What you've done here should be required for anyone getting a degree in EE. At least, if I was running a school I would require it. Actually, this is great stuff to teach to kids in gradeschool!
Maybe the next version of the $100 Bill will have a kite on it, helping to inspire many people toward a greater appreciation of this secret history of electricity.
And 2 years later I’m repeating what has been said, this is my new favorite channel.
@@Kathy_Loves_Physics, you know how physicists speak of The Big TOE.
Well your channel provides the SHOE to slip over the Theory Of Everything.
Thank you, Kathy, for the indeed clear description of Armstrong’s FM. Had been looking for this and per your comment, couldn’t find anything but the tragic storyline. I sincerely admire your ability to produce these wonderful videos!
You are a great presenter. Although I already know the technological details you present, the history you present and your enthusiasm make it a delight to watch.
I stumbled onto your video, as youtube suggested it. Happy to say I loved this explanation of FM! I work in radio so this is even more reason to understand how it works. Looking forward to more of your videos Kathy.
Another very enjoyable piece of EE history, well presented. Thank you, Kathy!
Facinating!! Can't wait to listen to all of your lectures
Major Armstrong gave his life and didn't back down in the face of corruption. He wouldn't take a pay off and sell out his soul. The superhet and FM are two of the most important contributions to the world of RF, and yet many people don't know who he was. Like the Hidden Figures of the space program, Major Armstrong was left out of many history books. Sarnoff and RCA stole more than Armstrong's patents for FM, they stole his soul and his life. Major Armstrong, you will NEVER be forgotten and all of us who work with RF THANK YOU for what you gave us.
Thanks for this series. The background about the people and the struggles of development of these technologies is fascinating
I recently came across your videos and have found all of them fascinating. Keep up the great work!
What a story! Thanks for telling it in such an interesting way. And in only 12 minutes.
Great video, ma'am. I'm glad the RUclips algorithm recommended this to me. I'll be watching more of your content. Have a good 2022!
Thanks
The clarity of your discussion is so much appreciated. Thank you.
Colonel Armstrong invented the limiter to eliminate noise often present AM transmissions as the was no intelligence carried in amplitude variations on a FM transmission. He must have foreseen AM Talk Radio.
Ha! It took me like 10 minutes to get the joke, but when I did... hehehe.
It's all right polarization circular modulation. Actually the limiter made FM the original digital radio as when limiting happens it is on or off hence digital mode just not PCM.
Yeah, to have foreseen Err Amerika so far in advance....
You are an excellent educator. I love the way your passion for the subject shines through you.
Edwin Howard Armstrong was the greatest electronics engineer that ever lived.
The world biggest profesional organization, IEEE, at the time IRE (Institute of Radio Engineers) also sanctioned him at Sarnoff's request...
Every wireless device to date contains something Armstrong created.
Thank you Kathy for this video.
no argument from me for the first statement.
Your videos are great! Understanding the history of how a technology came to be, helps to understand how it works. Thank You.
You have an instant sub...just because I Love Physics and History too, and you teach it so beautifully!
Very clear, concise discussion of FM radio and Armstrong's development of it, as well as the tragic outcome for Arnstrong. All of this was familiar material for me and I loved how you got right to the essentials.
Great video Kathy but what an incredibly tragic story, I am crying like a baby!
It’s so damn sad isn’t it? Sarnoff could be a real SOB when he wanted to.
That's a nice summary of Armstrong's invention (FM radio) and the legal battles that followed. Thanks Kathy.
Hello Kathy, I'm a herretic electronic hobbyist when it comes to simple radio circuitry, TRF for pure AM radio receivers : I built a straight--forward 3 transistor set using 2 FETs and 1 bi--polar. My home--brew schematic is an FET comon--source for the first--stage, a bi--polar for the 2 nd--stage, and another FET comon--source for the 3 rd--stage. Even with a single 240 uH tuning coil and matching 365 pF varriable capacitor, its performance rivals my cheap superheterodyne store--bought radio for RF gain and selectivity ( not the best, but satisfactory for my liking ) !!! My detector--circuit is a pump--rectifier using two 1N34A germanium--diodes. You are an enjoyable fantastic lady !!! Howie from 02446
Magnificent work Kathy, you are wonderful !! Thanks
Aww thanks
Kathy - You are clever. A well measured and beautifully presented video.
I researched my grandfather Elman Borscht Myers and discovered that he introduced Armstrong to Marconi. It was in written in a book that I now can't find. I heard from family that Marconi stole vaccuum tubes and patents from my grandfather. Many fell victim to the rush to claim credit! Sadly great men lost fortunes and some like Armstrong died defeated. Any info you have about this meeting would be greatly appreciated
Wow 😯
Wow , you're so good
I just discovered your channel
Very informative , thank you
Very interesting and informative. Thank you.
Armstrong is one of my heroes! Thanks for making this video and for also explaining his inventions in a clear and simple way! One thing that I heard from my professors when I learned about FM is that the RCA FM frequency allocations used narrower bandwidths than the ones proposed by Armstrong. That means that if we kept Armstrong original allocations we would have a higher fidelity FM radio than the one we listen to now.
But also less FM radio stations.
Very nice to watch and very interesting channel. Thank you Cathy!
Wonderful videos Kathy. I'm hooked!
Thanks for the informative video on FM and Armstrong. I grew up in NE NJ and visited the Armstrong tower at Alpine as a youngster. I learned some of the history then. I became an electronics engineer and amateur radio operator. I worked on microwave FM radio equipment in mid 1960's through 1980's. The technical descriptions resonated well with my experience. I've watched many of your videos, enjoyable and informative.
I am not an engineer but I feel like I grew up during some of this epic struggle. We were stuck with AM radios until about the mid 60s when the excitement was all about FM and FM stereo. It was great. I went on to work for a two-way FM radio provider (selling mainly Motorola equipment and repeater services) before that market was destroyed by the advent of cellphones.
Wow. Amazing story. I never knew that about Armstrong. I just discovered this channel this past week and love it!
Hey, this channel is a gift. I am learning history, electronics and english. Thank you.😃
Idk how it took me so long to find your channel but it makes me so happy 😁. I wish you were my teacher when I was in school you have an awesome ability to teach
Wow! Amazing presentation. Thank you!
Thank you for another fantastic video, I have to watch 10 times to understand the genius of this man ....
Thanks to FM radio, I’m an audiophile today, back in the early to mid 80’s, in Cuba my older brother an I, used to build these almost 5 meters long arrow shaped Yagi antennas with the rear pointing North to get stations from the US, we used to listen to the hit parades from back then the Super Q FM 108, in Stereo, from Miami, ( that was just one of many stations we picked up), we used to make mix tapes and loved it when that little Stereo Red indicator came on.
I always said that when it comes to music, I was born in the right era , (1971) but in the wrong country.
I love your content! And just started your book, "The Lightning Tamers." Thank you for the careful explanation in your videos.
Thanks for covering this topic!
Wow brilliant as a tv engineer in the UK in the 70s 80s i can now sit back and watch these fascinating facts
Great presentation watching from Thailand Thank you
I enjoy watching reruns of your shows.
Great content, Kathy, as always.
droh danka
This series are pure gold.
For any Radio or TV fan, Armstrong and Farnsworth forever will be our heros. 💫
Focusing on FM Stereo, introduced in the early 60s, turned in commercial success in the late 70s, it still is widely used in all it's glory and quality of sound, hi-fi standard (20-20K Hz).
I belive the broadcast range is the only limitation of FM, when compared with AM, for a same amount of power.
RUclips should really promote accessible and rigorous science videos like this.
Kathy Inspires People, could also be the name of this channel.
Thank you so much, please keep on the good work.
Cheers from 🇵🇹
Kathy, you are amazing! I was a "pirate" radio ham in Israel back in the early sixties... at the age of 14. I built all my equipment from 2nd WW junk...
Kathy that video was an excellent piece of American history. I love your presentation style and easy watch graphics. Thanks a lot.
They never told us about Armstrong when I was studying army radio techniques in the 70's !!
Bravo, enlightened viewer responds!
Armstrong's original broadcast tower, in Alpine, New Jersey still stands tall and is used continuously. New York City TV transmitters were all relocated there quickly after than world trade center was destroyed in '01.
This was a very good video on broadcasting... I never knew the history of AM vs. FM, but in 1974 obtained an FCC 1st phone. Thanks for a great technical video.
Love your videos! Keep up the good work!
So glad you liked it!
This is a good video. However, it suffers from lack of technical understanding, and as a result, some mistatements. For another, this is the only place I've seen Edwin H. Armstrong referred to as "Howard."
@@jimbelcher155 That is strange to me, as Armstrong's biographer Lawrence Lessing said he went by Howard in his book "Man of High Fidelity: A Biography of Edwin Howard Armstrong". That was also found in the book, "Empire of the Air". However, Glenn Beck was convinced that everyone called Armstrong "Edwin". Armstrong signed his patents E.H. Armstrong so it is hard to tell.
Thank you for this awesome video, Kathy. I wish you had been my teacher when I took college communications courses 50 years ago.
such an interesting story and you deliver it perfectly... thank you😍
This is great. I had a few professors that took time to teach us the importance of the history behind great inventions and discoveries.
I really appreciate this excellent video.
I really like your informative videos. Thanks.
This channel is a gem.
What a great video of the history! Thanks!
What an amazing channel! Bravo.
Kathy what a great job you do! Keep up the good work, outstanding.
Thank you
Well done. I'm an electrical engineer and your description is quite good while avoiding the more difficult math.
I wish she had been a teacher of mine in school, no I got stuck with teachers that put mold to sleep - boring. This was so well presented and so not boring...........Thank you for posting.
Wish I could have watched these videos of yours way back when all they had in high school science classes to calculate was a slide rule. I would have consumed all your videos back then like popcorn at a 35 cent Saturday double feature. The only question now is how many times to watch and rewatch all your videos until everything you’ve taught is completely internalized. You have converted dull science into fascinating, exciting drama that builds a hunger for more understanding. I recall you are writing a book….hooray!!!
Always informative and enjoyable. 🙂
Nice to know we haven't forgotten how all this works. Of course, this easy presentation made it easy to remember!
I just found your channel, I'm hooked! Fantastic!
Thanks Barry
These are so good. What a great history teacher!
This is friggin great..thank you for the presentation.
Oh my god! I'm new to this channel! LOVE IT!
Thanks
excellent video (and series), thanks! I'd love you to go deeper into the engineering, physics and math...
Extraordinary storytelling, thank you!
Excellently explained, bravo!
Thank you, I really struggled to figure that one out because Armstrong used a method that was not used for very long so it was really hard to find a description of how it worked and I actually just had to stare at his patent and try to figure out what he did and how it worked!
Enjoying these vids.
Excellent video! Thanks!
Excellent as usual. I wish you had more time and wherewithal to do these more often. Have you considered collaborations? Not with me, I mean someone with actual talent. 'The History Guy' here on RUclips comes to mind. Please keep going!
Jack D. Ripper I am hoping I will be back to doing one a week soon (a girl can dream). Feel like trying to collaborate would just take longer but I’ve never tried it. So glad u liked it and am soo happy to have survived radio
I think you do the videos very well. I think that with collaboration you get all those problems of 'design by commmittee'. I'd say keep going as you are, doubtless seeking input from others when you think you need it.
Excellent video, engaging and educating
breakablec so glad you liked it.
Great video as usual. It's a pity that the links in the description no longer work.
I remember reading a section of a textbook for college EE course about FM radio. It described how FM radio had obstacles as you mentioned, author wrote the FM broadcast band (88-108) was losing money in 1960s and there was consideration of reallocating that spectrum. PBS had a fascinating documentary about Sarnoff, Armstrong, and DeForest. It said DeForest managed to get himself labeled as inventor of tubes necessary for radio but IRE and others said Armstrong knows more and can describe principles better. Sarnoff described himself, "I don't get heartburns, I give them!" This documentary described how Sarnoff paid for Armstrong to work in static free radio system, all this was done on a floor in the Empire State building with a dedicated staff (imagine that, Silicon Valley like development in downtown NYC), when Armstrong and his team eventually demonstrated FM radio, "you can hear the difference between striking a wooden match from a paper match."
I have read Armstrong was an abusive person, as a Army captain in WWI he hit a subordinate so hard it broke his jaw. Also Armstrong had zero fear of heights as in that other video of him dancing on the high tower. In WW2 Armstrong granted patent rights to the govt for them to use whatever needed for free. But then everyone knew of FM and will use it anyway. Example is the Germans utilized FM for tank radios during WW2, and FM is far better than AM for land mobile radio.
Magnificent!
I've just finished to watch the videos from #30 to #36.
A real amazing history from Edison valve until Armstrong death.
Absolutely well done.
Thank you, Kathy.
You are welcome- glad you liked them.
Thank You Kathy for the history of FM radio. I had no idea that Armstrong was friends with Sarnoff.🥺
Appreciate all of your posts. 🤓
I stumbled onto this...great stuff!
Always with the good segue to the next video too.
You’re a great presenter. Thanks a million.
I recall reading the owner's manual for my grandparent's 1967 Dodge. It listed the radio as being an accessory (it was also the first car that I had ever ridden in that had power brakes, steering, and air conditioning). It said that they recommended AM radio, as they said the short distance range and line of sight signal made it impractical for automobiles.