# AM vs. FM radio and their content **URL:** \ **Category:** Factual Questions\ **Created:** [December 14, 2009, 2:55am UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178 "2009-12-14T02:55:40Z")\ **Posts on this page:** 11\ **Page:** 3
**Author:** ![LouisB](https://avatars.discourse-cdn.com/v4/letter/l/dfb087/32.png) [@LouisB](https://boards.straightdope.com/u/LouisB)\ **Post date:** [December 16, 2009, 4:10pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/41 "2009-12-16T16:10:18Z")
> [@elmwood](#): > > Interesting that you mention “old people”. I would imagine they stick with AM not because they’re all stuck with ancient cathedral radios that can’t tune FM, but rather because they’re creatures of habit. FM is a strange, mysterious land full of that rolling and rocking music these kids listen to nowadays. AM is familiar and comfortable, where they first heard about the Japs bombing Pearl Harbor. Their Buicks may boast impressive factory audio systems, but they’ll never take full advantage of it, instead sticking to the Music of Your Life and all-news stations on AM, and wondering why that slot by the stereo is too narrow to fit the sermon on tape from St. Gustavus Lutheran Church. Likewise, despite that V8 engine, they’ll never drive that Buick over 45 MPH. I’m an old people, closing in on 70, and I wouldn’t listen to AM radio on a bet. I use FM exclusively to listen to classical music from NPR. I also listen to several NPR programs on FM. The only people I know who still use AM are the rabid republicans I am presently surrounded by; these guys take Rush Limbaugh and his ilk as if they were all Moses, reading from the stone tablets inscribed by God. Listening to their conversations is downright scary to a guy like me. If I were to express my views, I would probably be stoned to death at the entrance to this gated community. ---
**Author:** ![KellyM](https://avatars.discourse-cdn.com/v4/letter/k/57b2e6/32.png) [@KellyM](https://boards.straightdope.com/u/KellyM)\ **Post date:** [December 16, 2009, 5:10pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/42 "2009-12-16T17:10:20Z")
> [@MsRobyn](#): > > This is another chicken-and-egg problem. In my market, there are few, if any, FM stations that play music that appeals to anyone over 60. Conversely, there are several AM stations that program for that demographic. So do older people listen to AM because they’re comfortable with the technology, with AM stations programming accordingly, or are older listeners listening to AM because there’s nothing for them on FM? Formats that remained on AM remained there because the fidelity increase offered by FM was not viewed by the station management to be of sufficient benefit to justify the increased costs and potentially decreased revenue (due to loss of footprint). FM stations cost more to operate than AM stations: FM station licenses typically cost more to obtain than AM licenses (although this has not always been true; the FCC is constantly jiggering the licensing structure), but more importantly, the cost of the transmitter for FM is typically higher. As FM is a line-of-sight band, an FM transmitter needs to be a high as possible; therefore, FM stations will tend to try to get their transmitters located on high points like mountaintops and tall buildings. The people who own such locations know that their altitude is desired and charge high rents. Conversely, an AM station doesn’t need altitude, and doesn’t have to be located as centrally as an FM station; what they do need is a good deal of space. As a result, AM stations are often located on the edge of or actually outside of town (e.g. WBBM in Chicago, whose transmitter is located in unincorporated DuPage County south of Schaumburg, or WIBC in Indianapolis, whose transmitter is in a former farm field well northwest of the city, just off I-65); such land is usually cheap to acquire and hold. The cost of the technology is about the same these days, although this also has not always been true. In any case, the decision of AM versus FM comes down to whether the increase in listener count from the better FM quality will offset the decreased revenue from lower listener count and increased operational costs. If not, then you go with AM. It’s not a chicken-and-egg problem at all; the current situation is entirely explainable as the consequence of an ongoing series of cost-benefit analysis decisions. Of course, once you’re going on a given format, you will be reluctant to move because changing frequency always costs you listeners in the short term, but that’s just part of the CBA that you are going to do each year (or however often) when you decide whether or not to renew your license, or your antenna site lease, etc. The FCC is constantly tweaking the licensing regime, increasing or decreasing license fees to push stations to go one way or the other on this analysis. On the specific issue of content for “old people” being more likely to be on AM, this is probably because people who are interested in such content are not going to be put off by the lower sound quality of AM; they might even prefer it because it reminds them of their younger days. There’s plenty of “old people” content on FM too; those stations no doubt appeal to listeners who do care about sound quality, or are on FM because they qualify for the segment of the FM band that the FCC sets aside for nonprofit and community broadcasters; that segment has lower power limits and much lower license fees; those considerations will often tilt the CBA back over to the FM side. In general the FCC would prefer to have small broadcasters on FM because they’re much less work for them to regulate. Inertia no doubt plays a role for many of these AM broadcasters as well; if your station is making a profit, why risk that by changing things? ---
**Author:** ![LouisB](https://avatars.discourse-cdn.com/v4/letter/l/dfb087/32.png) [@LouisB](https://boards.straightdope.com/u/LouisB)\ **Post date:** [December 16, 2009, 5:10pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/43 "2009-12-16T17:10:49Z")
> [@](#): > > Originally posted by KellyM: > It’s obviously possible to put tube radios into a car (we put tube radios into airplanes during WW2, after all) but there are all sorts of difficult issues involved. It does occur to me that many of the hard problems with tube radios in mobile environments are limited to transmitters, which generally require high voltages. I’d be curious, though: did those radios carry their own batteries, or were they driven from the car’s electrical system? Tube radios in cars were very heavy, I had to pull a few to be sent to radio repair shops. I have to comment re radios in aircraft; it wasn’t feasible to put radios in aircraft for years, due to the fact that as the plane gained altitude, the outside temperature dropped and that drop in temperature caused the frequency of the radio to change, and what it changed to was anybody’s guess. Enter the quartz crystal unit and the frequency could be stabilized over a very wide temperature range. The same thing applied to field radios and ships at sea, as well as other communications equipment. I’ve forgotten what the name of the station was, but the first commercial broadcast station to use a quartz crystal unit to stabilize frequency was in New York state and that station adapted quartz crystal units sometime in the 1920s and that paved the way for other stations to do the same. You might guess that I spent a lot of years in the quartz crystal industry and you would be correct. I could go on and on about their significance during the war but I won’t. I will say that in terms of priority and money spent, the quartz crystal industry was second only to the Manhattan project. The quartz crystal industry was a critical industry for many years but it has now been forfeited to the far east, which is why I am no longer emplyed within my beloved industry. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [December 16, 2009, 5:40pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/44 "2009-12-16T17:40:49Z")
LouisB, have you met KellyM? KellyM, LouisB. LouisB, KellyM. LOL ---
**Author:** ![KellyM](https://avatars.discourse-cdn.com/v4/letter/k/57b2e6/32.png) [@KellyM](https://boards.straightdope.com/u/KellyM)\ **Post date:** [December 16, 2009, 5:47pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/45 "2009-12-16T17:47:39Z")
> [@LouisB](#): > > Enter the quartz crystal unit and the frequency could be stabilized over a very wide temperature range. The same thing applied to field radios and ships at sea, as well as other communications equipment. I’ve forgotten what the name of the station was, but the first commercial broadcast station to use a quartz crystal unit to stabilize frequency was in New York state and that station adapted quartz crystal units sometime in the 1920s and that paved the way for other stations to do the same. I am reminded of a story regarding a religious broadcaster in the early days of radio. Their transmitter was not well-stabilized and tended to wander, causing interference with other stations. When ordered by the FRC (the predecessor to the FCC) to take steps to stabilize their frequency and stop interfering with other stations, they responded defiantly to the FRC with “God will choose my frequency”. (Sadly, the very excellent radio history website where I first read of this appears to have gone offline.) ---
**Author:** ![KellyM](https://avatars.discourse-cdn.com/v4/letter/k/57b2e6/32.png) [@KellyM](https://boards.straightdope.com/u/KellyM)\ **Post date:** [December 16, 2009, 6:14pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/46 "2009-12-16T18:14:58Z")
> [@KellyM](#): > > I am reminded of a story regarding a religious broadcaster in the early days of radio. Their transmitter was not well-stabilized and tended to wander, causing interference with other stations. When ordered by the FRC (the predecessor to the FCC) to take steps to stabilize their frequency and stop interfering with other stations, they responded defiantly to the FRC with “God will choose my frequency”. (Sadly, the very excellent radio history website where I first read of this appears to have gone offline.) Aha, found it! From [http://www.w0abr.com/\_hamshack/history06.html:](http://www.w0abr.com/_hamshack/history06.html:) > [@](#): > > An interesting example of this was the Los Angeles station of “Sister” Aimee Semple McPherson, an evangelist who was the leader of the International Church of the Foursquare Gospel. Her station was notorious for drifting up and down the broadcast band. When the Federal Radio Inspectors tried to keep her on frequency, she imperiously wrote to Secretary Hoover, demanding that his “Minions of Satan” stay away from her transmitter. The Almighty would choose her Wavelength, she wrote, not the Department of Commerce. ---
**Author:** ![tetranz](https://avatars.discourse-cdn.com/v4/letter/t/a587f6/32.png) [@tetranz](https://boards.straightdope.com/u/tetranz)\ **Post date:** [December 16, 2009, 6:22pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/47 "2009-12-16T18:22:37Z")
> [@KellyM](#): > > The short of it is that while you could put an AM radio into a device the size of an MP3 player, it would have extremely poor reception because of the lack of a suitable antenna system. This isn’t as much a problem with FM broadcast because FM broadcast uses radio waves of about 3 meters in length; a functional antenna for this wavelength can be made small enough to tuck inside the case of an MP3 player of reasonable size. I think most MP3 players with an FM radio use the headphone cable as the antenna. ---
**Author:** ![whitetho](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whitetho/32/1059_2.png) [@whitetho](https://boards.straightdope.com/u/whitetho)\ **Post date:** [December 17, 2009, 8:45pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/48 "2009-12-17T20:45:39Z")
> [@LouisB](#): > > I’ve forgotten what the name of the station was, but the first commercial broadcast station to use a quartz crystal unit to stabilize frequency was in New York state and that station adapted quartz crystal units sometime in the 1920s and that paved the way for other stations to do the same. “In 1926 the A. T. & T. radio station WEAF in New York City became the first radio station in the United States to control its frequency with a quartz crystal unit” according to [A History Of The Quartz Crystal Industry In The USA](http://www.ieee-uffc.org/main/history.asp?file=bottom) by Virgil E. Bottom. WEAF later became WNBC and is now WFAN, still in NYC. ---
**Author:** ![whitetho](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whitetho/32/1059_2.png) [@whitetho](https://boards.straightdope.com/u/whitetho)\ **Post date:** [December 17, 2009, 8:50pm UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/49 "2009-12-17T20:50:39Z")
> [@](#): > > An interesting example of this was the Los Angeles station of “Sister” Aimee Semple McPherson, an evangelist who was the leader of the International Church of the Foursquare Gospel. Her station was notorious for drifting up and down the broadcast band. When the Federal Radio Inspectors tried to keep her on frequency, she imperiously wrote to Secretary Hoover, demanding that his “Minions of Satan” stay away from her transmitter. The Almighty would choose her Wavelength, she wrote, not the Department of Commerce. Hoover claimed in his bibography that she sent him a telegram, but no one has been able to find it, and the church claims it never happened. So it may end up being only a “good story”. ---
**Author:** ![LouisB](https://avatars.discourse-cdn.com/v4/letter/l/dfb087/32.png) [@LouisB](https://boards.straightdope.com/u/LouisB)\ **Post date:** [December 23, 2009, 2:34am UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/50 "2009-12-23T02:34:56Z")
> [@whitetho](#): > > “In 1926 the A. T. & T. radio station WEAF in New York City became the first radio station in the United States to control its frequency with a quartz crystal unit” according to [A History Of The Quartz Crystal Industry In The USA](http://www.ieee-uffc.org/main/history.asp?file=bottom) by Virgil E. Bottom. WEAF later became WNBC and is now WFAN, still in NYC. I had the pleasure of knowing Dr. Bottom fairly well; he was one of my mentors in the industry. He was also one of the very few men who knew how to manufacture quartz crystal units when the war started; he was teaching physics one day and was commandeered by the Army the next. He was a very entertaining man who could tell stories about the old days better than anyone I ever knew. He was still answering questions for me until shortly before his death. I still miss chatting with him. ---
**Author:** ![elmwood](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/elmwood/32/3060_2.png) [@elmwood](https://boards.straightdope.com/u/elmwood)\ **Post date:** [December 25, 2009, 3:36am UTC](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178/51 "2009-12-25T03:36:36Z")
> [@salinqmind](#): > > I’m probably ‘old’ to you…let’s say over 50 but under 60. Just out of curiosity, what do you think I listen to on the radio, or what YOU think I listen to on the radio? Stations that play bands with “and His Orchestra” in their names, with DJs waxing nostalgic about long-gone outdoor dance clubs out in the country and neighborhood ballrooms. Commercials for prescription-only drugstores, Buick dealerships, assisted living communities, and funeral homes. 😃 Seriously, I can’t say. You might be the target demographic for “classic hits” stations, but for all I know you’re an NPR or alt rock fan. Let’s hope your tastes haven’t ossified quite so soon. 🙂 [Previous page](https://boards.straightdope.com/t/am-vs-fm-radio-and-their-content/521178.md?page=2)