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FM radio invention
- Thread starter jbl
- Start date
K.M. Richards
Program Director, The Eighties Channel™
Yes, Major Armstrong was a genius. It is a black mark on history that General Sarnoff litigated him to his breaking point and untimely end as a result.
Of course, Armstrong had the last laugh, posthumously. FM is the dominant aural transmission mode now, and AM is dying a slow death.
Of course, Armstrong had the last laugh, posthumously. FM is the dominant aural transmission mode now, and AM is dying a slow death.
Major Edwin Howard Armstrong's wife, Marion MacInnis, was formerly the secretary to David Sarnoff.
The relationship between the three was a pivotal, and ultimately tragic, part of radio history:
The relationship between the three was a pivotal, and ultimately tragic, part of radio history:
- The courtship: Major Armstrong met Marion when she worked for Sarnoff, who was an executive at the Radio Corporation of America (RCA). In 1923, as a wedding gift for Marion, Armstrong presented her with the world's first portable superheterodyne radio—a technology he invented.
- The bitter rivals: Armstrong and Sarnoff, once friends and allies, became bitter enemies. Armstrong's inventions were critical to RCA's success, but Sarnoff, as the head of RCA, was not willing to pay Armstrong the royalties he felt he was owed for the new FM radio technology.
- The aftermath: The long, expensive legal battles over patents took a severe toll on Armstrong's health and fortune. In 1954, after a breakdown in their marriage, Armstrong died by suicide. Marion Armstrong continued the legal fight on behalf of her late husband and eventually secured a successful settlement against RCA.
She then allowed the patent to lapse and the technology became public domain. For the first time, electronics manufacturers could include FM to their radios without paying a royalty. The availability of FM to the public increased. It happened at a time when the FCC passed it's format non-duplication rule. The combination of the availability of cheap FM radios with new formats caused listening to explode. Within ten years, FM listening started to exceed AM.
Even without listening to it, I can tell that video was AI-generated. All of the images it uses were. Try reading a book, instead of watching/listening to AI slop.
His widow formed a non-profit foundation that keeps his memory alive. The tower he built in Alpine NJ is still there, and hosts several FM antennae.
www.armstrongmemorialfoundation.org
home
EDWIN HOWARD ARMSTRONG, 1890-1954 A pre-eminent electrical engineer, who through his extraordinary inventions, FM radio among them, contributed immeasurably to the advancement of wireless communications and broadcasting.
www.armstrongmemorialfoundation.org
K.M. Richards
Program Director, The Eighties Channel™
The bottom line is that Sarnoff was a major league a-hole.
Another example: When WNBC-TV was still experimental license W2XBS, Sarnoff decided to begin commercial operation and the FCC had to admonish him over it.
Then, when DuMont started selling television sets in 1938, Sarnoff took his station off the air, even though it had a semi-regular program schedule, until the World's Fair in April 1939 ... because Sarnoff wanted RCA to be the first to offer sets and had planned to make the announcement then, on the first official day of commercial service.
Another example: When WNBC-TV was still experimental license W2XBS, Sarnoff decided to begin commercial operation and the FCC had to admonish him over it.
Then, when DuMont started selling television sets in 1938, Sarnoff took his station off the air, even though it had a semi-regular program schedule, until the World's Fair in April 1939 ... because Sarnoff wanted RCA to be the first to offer sets and had planned to make the announcement then, on the first official day of commercial service.
I'm finding that this thread is quite informative, enough to not even bother with the video!
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The main reason why Sarnoff built obstacles for FM was that he wanted consumers to be able to spend money on TV, not on cheaper FM radios.
The end of the Armstrong patents that restricted FM set production occurred in the early 60's, but those royalties were minimal... a few cents per device. But at the same time in the earliest 60's, FM AFC was developed, removing the significant negative of drifting. FM stereo was also introduced soon after (but was very slow in station acceptance). But it was not until the later 60's when non-duplication was prohibited for many stations that owners tried to make those stations... some approaching two decades in age...
I bought my first AM/FM radio in 1958 or early 1959 when I started part-timing and go-fering at an actual FM. It only cost a dollar or so more than a plain AM radio and had a "real leather" case! What restricted use of FM was the lack of attractive programming and the dramatic decline in the number of stations in the prior decade (in the 50's, nearly a third of all FMs signed off).
An excellent book you can read online thanks to @davideduardo is "Empire Of The Air: The Men Who Made Radio"... it is an excellent history and goes into detail on Marconi, Sarnoff and Armstrong.
A decade earlier, Farnsworth & Sarnoff/RCA were battling over that technology.
The one thing Sarnoff did right (whether he intended to or not, likely not) was to have the FCC move the FM band from 42-50 MHz to 88-106 (later 108) MHz. Had the wartime FM band continued as-is, the skip, mutual interference, and band crowding would have killed it in the 1950s. 8 MHz was just not enough.
Of course, Sarnoff pushed moving FM up the dial so that all the Armstrong work on the 42-50 mHz band would be made useless, setting the development back by years. He essentially tossed a bomb into FM's basement. Of course, WW II further slowed down FM development, and it gave Sarnoff time to come up with viable TV systems that he could make more money on than any kind of radio.
But the bomb was necessary. I'm not saying Sarnoff was doing anything out of the goodness of his heart (something that didn't exist), but the move had to happen. Once the band was moved, receivers were made that covered both bands. It took until 1948 for existing 42-50 MHz stations to move to the new band.
Tube technology also advanced during the war, allowing both FM and TV transmitters and receivers to work well above the 80 MHz or so (at best) limit of the early 1940s. Not only was FM limited to 8 MHz, but TV was effectively limited to four channels (50-56 and 60-
EDIT: Channels 2-4 were 60-66, 66-72, and 72-78 MHz, with Channel 4 moving to 78-84 MHz later on.
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If FM had stayed on the lower band, it probably wouldn't have remained limited to 8 MHz -- as I recall, there was a proposal to expand it to 41-56 MHz, which would have provided almost doubled the spectrum for FM radio. So apparently there was an awareness that 8 MHz wasn't enough if the service were to succeed.
Even with an expansion upwards from 50 mcs, low-band FM would have ended up being problematic simply because of the propagation characteristics at those frequencies.
E-skip is much more likely at 45 than at 90 MHz, as we know now (but didn't know well in Armstrong's era), which would have led to lots of interference in the summertime once the number of stations on the air began to grow substantially.
It wasn't much of a problem in the 1940s because most of the early FM stations were heavily concentrated on the east coast, with almost none operating in the areas of the Midwest where they would have been most likely to interfere via e-skip.
The problem would have been further exacerbated, ironically, by Armstrong's desire to make FM a wide-coverage regional service. That would have meant more powerful transmitters but also relatively weak protected signals in fringe areas, another recipe for both generating e-skip and suffering interference from it.
It would also have wreaked havoc in the summer on Armstrong's plan to daisy-chain FM signals over the air to avoid the need to use expensive AT&T long lines. If e-skip wipes out just one hop of the daisy chain, the rest of the "network" is lost.
Portable receivers would also have needed much bigger antennas for the 7-meter wavelengths of early FM compared to the 3-meter wavelengths "upstairs."
The move may have been somewhat driven by malice on Sarnoff's part, but it also made solid engineering sense in the end.
(Except for butting the top of FM broadcast right against the aircraft band. That was and is unfortunate.)
E-skip is much more likely at 45 than at 90 MHz, as we know now (but didn't know well in Armstrong's era), which would have led to lots of interference in the summertime once the number of stations on the air began to grow substantially.
It wasn't much of a problem in the 1940s because most of the early FM stations were heavily concentrated on the east coast, with almost none operating in the areas of the Midwest where they would have been most likely to interfere via e-skip.
The problem would have been further exacerbated, ironically, by Armstrong's desire to make FM a wide-coverage regional service. That would have meant more powerful transmitters but also relatively weak protected signals in fringe areas, another recipe for both generating e-skip and suffering interference from it.
It would also have wreaked havoc in the summer on Armstrong's plan to daisy-chain FM signals over the air to avoid the need to use expensive AT&T long lines. If e-skip wipes out just one hop of the daisy chain, the rest of the "network" is lost.
Portable receivers would also have needed much bigger antennas for the 7-meter wavelengths of early FM compared to the 3-meter wavelengths "upstairs."
The move may have been somewhat driven by malice on Sarnoff's part, but it also made solid engineering sense in the end.
(Except for butting the top of FM broadcast right against the aircraft band. That was and is unfortunate.)