Howard Armstrong & Frequency Modulation: History and Physics
video description
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.
Date: 2022-12-27
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Comments and reviews: 19
David
I first started to watch your videos somewhere in the 40's, but decided to start at #1 since you made so many references to your earlier videos. I am back at 37 and have realized that from static electricity to the word electricity a lot of the history and discoveries have been somewhat serendipitous. In the search for answers to some questions other discoveries were made along the way by parties at different ends of the spectrum, only later to realize that their discoveries were somewhat related. Furthermore it sometimes took a third party to tie it all together. I was also stricken by the fact that we had two kinds people, those in it for the science, and those willing to appropriate that science for profit and wrongfully claiming it as their own. There are so many people on both sides of the hemisphere that have contributed to this field, and had it not been for political referendum the field I feel would have advanced much faster. I majored in electronics in 76 but girls soon became a distraction for me, but I never lost the bug for the field. Thank you for sharing the history and doing the work to bring it to light. I am looking forward to continuing with the rest of your videos, as well as looking forward to your upcoming book.
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I first started to watch your videos somewhere in the 40's, but decided to start at #1 since you made so many references to your earlier videos. I am back at 37 and have realized that from static electricity to the word electricity a lot of the history and discoveries have been somewhat serendipitous. In the search for answers to some questions other discoveries were made along the way by parties at different ends of the spectrum, only later to realize that their discoveries were somewhat related. Furthermore it sometimes took a third party to tie it all together. I was also stricken by the fact that we had two kinds people, those in it for the science, and those willing to appropriate that science for profit and wrongfully claiming it as their own. There are so many people on both sides of the hemisphere that have contributed to this field, and had it not been for political referendum the field I feel would have advanced much faster. I majored in electronics in 76 but girls soon became a distraction for me, but I never lost the bug for the field. Thank you for sharing the history and doing the work to bring it to light. I am looking forward to continuing with the rest of your videos, as well as looking forward to your upcoming book.
reply
Yves
Very interesting video. Though the experiment with the bad contact transient current making noise on the AM program but not on the FM program is not on my opinion full proof. The radiated spectrum due to the transient current on the wire has a natural decay with frequency. The nominal AM Band is around 1 MHz, whereas the nominal FM band is around 100MHz. The order of magnitude on frequency is most probably the main reason of the less noise. It is also clearly the case of the atmospherics discharge that makes a lot of noise in the low frequency used by AM radio and much lower noise as frequency climbs. As an example, the old analog TV was also working on such high frequency and was generally using AM modulation for the sound and had a good sound quality with much less noise than the AM radio.
To conclude, the effect of the limiter stage, when it does limit the amplitude of strong received signals, in conjunction with a well tuned ratio detector will limit the static noise and the effect of any amplitude modulation, but the experiment you did is not a true illustration of the fact. and I love you too!
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Very interesting video. Though the experiment with the bad contact transient current making noise on the AM program but not on the FM program is not on my opinion full proof. The radiated spectrum due to the transient current on the wire has a natural decay with frequency. The nominal AM Band is around 1 MHz, whereas the nominal FM band is around 100MHz. The order of magnitude on frequency is most probably the main reason of the less noise. It is also clearly the case of the atmospherics discharge that makes a lot of noise in the low frequency used by AM radio and much lower noise as frequency climbs. As an example, the old analog TV was also working on such high frequency and was generally using AM modulation for the sound and had a good sound quality with much less noise than the AM radio.
To conclude, the effect of the limiter stage, when it does limit the amplitude of strong received signals, in conjunction with a well tuned ratio detector will limit the static noise and the effect of any amplitude modulation, but the experiment you did is not a true illustration of the fact. and I love you too!
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Jonas
More about Sarnoff.
Sarnoff didn't just pursue Armstrong. Sarnoff was an enemy of revolutionary designs and in favor of evolutionary designs. So it was with Armstrong's FM and also with Peter Carl Goldmark's sequential color TV system of CBS Labs. Sarnoff bet on compatible color TV, without the need to occupy other spectrum bands to allocate the sequential 144-fields, 24 frames per second. color system. Sarnoff put the brakes on the CBS project with help from the US government, which banned the use of mumetal, indispensable for Goldmark's sequential TV. The Sarnoff lobby had once again won another battle.
If Sarnoff were alive, digital TV would be compatible with analog TV!
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More about Sarnoff.
Sarnoff didn't just pursue Armstrong. Sarnoff was an enemy of revolutionary designs and in favor of evolutionary designs. So it was with Armstrong's FM and also with Peter Carl Goldmark's sequential color TV system of CBS Labs. Sarnoff bet on compatible color TV, without the need to occupy other spectrum bands to allocate the sequential 144-fields, 24 frames per second. color system. Sarnoff put the brakes on the CBS project with help from the US government, which banned the use of mumetal, indispensable for Goldmark's sequential TV. The Sarnoff lobby had once again won another battle.
If Sarnoff were alive, digital TV would be compatible with analog TV!
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Max
The US has the only judicial system in the developed world (the only I know off, btw - and I'm from a developing country) that makes the person who wins a judicial case to pay for the costs. This causes problems like the one she described: the owner of RCA lead Armstrong to bankruptcy before he could win the case forcing him to make a deal. LegalEagle said that is the single most important thing that should be changed in the US legal system for it gives an unfair advantage for those with more money.
Thanks for the video! I knew how FM worked and why it is immune to static but had never seen how de demodulation was done in analog systems. BTW, what is SSB? Thanks!
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The US has the only judicial system in the developed world (the only I know off, btw - and I'm from a developing country) that makes the person who wins a judicial case to pay for the costs. This causes problems like the one she described: the owner of RCA lead Armstrong to bankruptcy before he could win the case forcing him to make a deal. LegalEagle said that is the single most important thing that should be changed in the US legal system for it gives an unfair advantage for those with more money.
Thanks for the video! I knew how FM worked and why it is immune to static but had never seen how de demodulation was done in analog systems. BTW, what is SSB? Thanks!
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soumitra
Sorry,
this was not so lucid as her other lectures. Especially the substitution of Amplitude Modulation by Frequency Modulation in achieving noise-free transmission of aerial sound does not follow with the intended obviousness, clarity and ease, which is supposed to be the essence of such lectures. Maybe, a viewer like me needs further technical background to understand all this.
But then, what is the use of such popular-styled lectures when the true need is for a formal and rigid undergraduate physics class?
Was this lecture at all intended for the untrained but interested scientific layman? I think, not.
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Sorry,
this was not so lucid as her other lectures. Especially the substitution of Amplitude Modulation by Frequency Modulation in achieving noise-free transmission of aerial sound does not follow with the intended obviousness, clarity and ease, which is supposed to be the essence of such lectures. Maybe, a viewer like me needs further technical background to understand all this.
But then, what is the use of such popular-styled lectures when the true need is for a formal and rigid undergraduate physics class?
Was this lecture at all intended for the untrained but interested scientific layman? I think, not.
reply
Charles
Great video. usurping FM was not the only discovery scientist who was ripped off by Sarnoff as you will give testament to the inventor of television. I remember seeing this fellow on Whats my Line TV show back in the late 50s Early 60s and he won a carton of cigarettes. I remember how he looked. and I thought to my 12 year old self: why is this guy not rich beyond his dreams. I knew something was up and he was bullied off his discovery and his well earned fortune: sad! Love the videos. so informative with the personal stories!
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Great video. usurping FM was not the only discovery scientist who was ripped off by Sarnoff as you will give testament to the inventor of television. I remember seeing this fellow on Whats my Line TV show back in the late 50s Early 60s and he won a carton of cigarettes. I remember how he looked. and I thought to my 12 year old self: why is this guy not rich beyond his dreams. I knew something was up and he was bullied off his discovery and his well earned fortune: sad! Love the videos. so informative with the personal stories!
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RdgJr619
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 youve 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!
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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 youve 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!
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titicoqui
how tragic but what brutal honesty no details omitted there should be a book about all just such once ineffably sweet partnerships gone unspeakably sour the timeless story of betrayal perhaps the otto hahn and lise meitner tragedy is the one that most resonates with me
in the music world especially there are so many friend turned enemy stories thank you thank you for your insightful treasures not only into the realm of science but in the all too familiar realm of human nature itself
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how tragic but what brutal honesty no details omitted there should be a book about all just such once ineffably sweet partnerships gone unspeakably sour the timeless story of betrayal perhaps the otto hahn and lise meitner tragedy is the one that most resonates with me
in the music world especially there are so many friend turned enemy stories thank you thank you for your insightful treasures not only into the realm of science but in the all too familiar realm of human nature itself
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Mark
Sarnoff stole electronic television from Farnsworth. Edison, Westinghouse, Alexander Graham Bell, Watson and Krick all thieves. The patent system does not protect the small independent inventor.
BTW I had to do the calculations for both AM and FM radio modulation in a senior course on information theory. When I hear about digitization distortion of analog signals converted to digital and back to analog I have to laugh thinking about the capacitor in an AM detector circuit.
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Sarnoff stole electronic television from Farnsworth. Edison, Westinghouse, Alexander Graham Bell, Watson and Krick all thieves. The patent system does not protect the small independent inventor.
BTW I had to do the calculations for both AM and FM radio modulation in a senior course on information theory. When I hear about digitization distortion of analog signals converted to digital and back to analog I have to laugh thinking about the capacitor in an AM detector circuit.
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Peter
Thanks for your interesting video. I bought an AM/FM Zenith tube radio in Florida back in 2002. I was curious about the Armstrong label underneath as I'd heard a bit about the legal wranglings, but you have explained it clearly. I used the radio in the UK, and now in France via a 240/120 transformer. I think the demodulation system is slightly different between the US & Europe (something about milliseconds, but it sounds OK to me.
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Thanks for your interesting video. I bought an AM/FM Zenith tube radio in Florida back in 2002. I was curious about the Armstrong label underneath as I'd heard a bit about the legal wranglings, but you have explained it clearly. I used the radio in the UK, and now in France via a 240/120 transformer. I think the demodulation system is slightly different between the US & Europe (something about milliseconds, but it sounds OK to me.
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Paublus
Thank you for these incites into patents and the work done to even achieve television by an Idaho inventer. This is all why the Red Chinese theft without remuneration to America because in Communism you own nothing. Make a billion dollars in China and when the Communist maggots get through with you you have disappeared. Thanks Communists for taking all my forefathers ability and making it so cheap even Walmart can sell it.
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Thank you for these incites into patents and the work done to even achieve television by an Idaho inventer. This is all why the Red Chinese theft without remuneration to America because in Communism you own nothing. Make a billion dollars in China and when the Communist maggots get through with you you have disappeared. Thanks Communists for taking all my forefathers ability and making it so cheap even Walmart can sell it.
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apoulios
Daniel Earl Noble. joined Motorola as director of research in 1940. His Link SCR-300 backpack transmitter and receiver. provided the first practical FM band transmission for military use. Introduced in 1943, and first used at the Battle of Anzio, the portable FM field radio allowed communication with less interference than the AM walkie-talkie systems that had been used earlier in World War II.
Source: Wikipedia
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Daniel Earl Noble. joined Motorola as director of research in 1940. His Link SCR-300 backpack transmitter and receiver. provided the first practical FM band transmission for military use. Introduced in 1943, and first used at the Battle of Anzio, the portable FM field radio allowed communication with less interference than the AM walkie-talkie systems that had been used earlier in World War II.
Source: Wikipedia
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Jonas
When FM was invented there were no high fidelity recording and playback systems. So Armstrong's system could only be put to good use on live radio shows. Thus, it was only with the advent of the 525-line TV that FM sound came to be used. Sound recording systems on magnetic tapes and vinyl records became popular in the late 1950s. From then on, Armstrong's FM system gained its space in sound broadcasting.
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When FM was invented there were no high fidelity recording and playback systems. So Armstrong's system could only be put to good use on live radio shows. Thus, it was only with the advent of the 525-line TV that FM sound came to be used. Sound recording systems on magnetic tapes and vinyl records became popular in the late 1950s. From then on, Armstrong's FM system gained its space in sound broadcasting.
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Frank
What a fascinating while tragic story, all because of greed. Instead of such rivalry, Sarnoff and Armstrong should have joint forces to take the radio technology to its maximum development during that time and create an even bigger empire. Again Kathy, you are such a great story teller, intermixing the events and the technology together, showing your great knowledge of both. Thank you so much!
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What a fascinating while tragic story, all because of greed. Instead of such rivalry, Sarnoff and Armstrong should have joint forces to take the radio technology to its maximum development during that time and create an even bigger empire. Again Kathy, you are such a great story teller, intermixing the events and the technology together, showing your great knowledge of both. Thank you so much!
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Stephen
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.
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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.
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Belper
One problem with FM is that it needs a much wider bandwidth than AM. In the UK it's transmitted on VHF Band 2 (88 - 108 Mhz IIRC. The BBC started FM broadcasts in the late 50s which was the bane of my life: ) Having learned how AM receivers worked I then had to learn about Foster-Seeley and other discriminators! Technology was tough in those days!
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One problem with FM is that it needs a much wider bandwidth than AM. In the UK it's transmitted on VHF Band 2 (88 - 108 Mhz IIRC. The BBC started FM broadcasts in the late 50s which was the bane of my life: ) Having learned how AM receivers worked I then had to learn about Foster-Seeley and other discriminators! Technology was tough in those days!
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Yves
Armstrong and Memory alive: Mit Armstrong Lizenz hergestellt (made with Armstrong License) is what is printed on the back of my german Telefunken Operette7 radio, delivered in 1957. I have this radio to work fine and steady and give me the pleasure of good music program every day, until DAB will kill those radio stars.
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Armstrong and Memory alive: Mit Armstrong Lizenz hergestellt (made with Armstrong License) is what is printed on the back of my german Telefunken Operette7 radio, delivered in 1957. I have this radio to work fine and steady and give me the pleasure of good music program every day, until DAB will kill those radio stars.
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CampKohler
Einstine was once asked to explain radio. He said first he would explain the telegraph. Imagine a cat with its tail in New York City and its head in Los Angeles. When you pull its tail in New York City, its head meows in Los Angeles. Radio is the same thing except there is no cat.
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Einstine was once asked to explain radio. He said first he would explain the telegraph. Imagine a cat with its tail in New York City and its head in Los Angeles. When you pull its tail in New York City, its head meows in Los Angeles. Radio is the same thing except there is no cat.
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agentstona
ELECTRICITY ELECTRICITY This beat is catching onto me. hahaha this episodes are so beautiful and they teach more tin 10 minutes than what some teacher at school spends 6 months to teach in a boring way. thanks for this videos MORE ELECTRICITY ELECTRICITY VIDEOS FROM YOU
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ELECTRICITY ELECTRICITY This beat is catching onto me. hahaha this episodes are so beautiful and they teach more tin 10 minutes than what some teacher at school spends 6 months to teach in a boring way. thanks for this videos MORE ELECTRICITY ELECTRICITY VIDEOS FROM YOU
reply
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