AM frequencies can also bounce off water. So you can get cases where it hops into the atmosphere, off the ocean (or lake), back off the atmosphere, etc. and gets half way around the planet. In the military, we'd occasionally tune in our HF into a local AM station for music. Half-hour later, you could hear a faint signal, re-tune it a few hundred megahertz and you'd be listening to an Iranian station. You could often guess the station by where it was dark at the time of day you are hearing it and eliminating languages you could identify. We had a big chart of world stations which could finally tell you who it was.
@@olafelsberry420 No. Summer job in the Canadian militia with a radio communications trope. Just a large AM receiver in the back of the truck along with smaller VHF units. We'd often tune the HF to some AM radio station and listen to music while up all night while doing exercises on the VHF units. You just had to make sure you didn't grab the wrong mic when answering or else everyone in 50 miles listening to the local radio station could hear you. Fun times.
@@VicGreenBitcoin Not so. AM is from 500 to 1,700 kHz, FM 88 to 108 MHz. Both will bounce off water, but FM is scattered more by water (i.e. clouds, rain, or humidity) and most importantly shorter wave lengths are not reflected back by the ionosphere. On a raining day, VHF radios really suffer in range while HFs far less effected. For bouncing, both with bounce off a large body of water. However, VHFs go off into space while HFs will bounce back from the upper atmosphere. Hence why we could detect an Iranian radio station bouncing a half-dozen times off the upper atmosphere and oceans. We never detected VHF radio signals at any long distance while HF often had odd background interference from distance sources.
@@BW022 No, AM and FM are not necessarily set by frequency . You can talk perfectly on 1700kHz on FM if you set the receiver on FM to (Most normal radio receivers have not that option). Also you can perfect modulate Am on 88 to 108 Mhz band, remember just a little higher on 118 Mhz air-planes use AM. So its not the AM that makes the skip trip...just saying
But... the sad thing it does. 2 questions for the flat earthers. 1 why would NASA and the government lie, and 2 because of that layer in the video, and the fact it's curved, the radio waves go farther. It works on a flat earth but not when the wave is curved. Also, if the earth is flat, does it spin? Does it move? Does it have gravity? And is it in space?. Answer all of these questions please.
Brendan Nichols I think you took that wayyyyy to close to home... I was simply commenting on his sarcastic use of "supposedly"... I'm well aware of the spheroid nature of the Earth.
+AwesomeGuy , I'm putting up a video for the Project for Awesome (hopefully tomorrow). I have a full-time job though, so my uploads for now will remain mostly every 2-3 weeks.
KOMO in Seattle is correct, but for Chicago it’s WMVP for our radio station. All radio stations in the US are split by prefix along the Mississippi River. K to the west, W to the east.
Vijaya Teja Rebbapragada I don't think so. He said "Without the bounce", which is indicative of FM, and was explaining how FM radio has the drawback of reaching a shorter distance than AM day and night. AM frequencies on the other hand, reach further than FM during the day, and significantly farther still at night, due to the bounce off the ionosphere. As for the curvature bit, he was saying that the curvature was considered in the calculation. On a Flat Earth, the range of FM radios would be significantly larger as there would be an infinite line of sight to the tower, the only consideration being the barriers in the way, including skyscrapers, mountains and as FEers would be quick to point out, the air itself, that would scatter the signal over distance.
Vijaya Teja Rebbapragada No, it's clearly meant to be FM, it just tells us the range difference between AM (~~150 km radius) and FM (~~50 km radius). [just for clarification, this means FM waves from one station can be picked up in an area of ~8.000 square Kilometers, while AM in an area of ~70.000 km {which is roughly the size of Ireland, if my memory serves me right}]
One night, during a vacation in the US, I remember waiting in the car for our parents who were visiting with family (listening to old people talk gets boring, obviously). We decided to turn on the AM radio. We were able to pick up two or three stations conflicting with each other. It kind of sounded like they were arguing too. So that was entertaining.
Gee, I heard that and thought the opposite: "No, a LARGER stab wound is better [at stopping a bad guy]." I guess it depends if you see yourself as the stabber, or the stabee!
In the last week of November 1994 I picked up an AM radio signal late at night being broadcast from Denver, Colorado while driving in Southern Illinois. The station identified itself as "The Blow Torch of the West".
Every night, I can pick up KSL News Radio (1160 AM) from all the way in Boise, ID. they are based in Salt Lake City, UT. I also once picked up a signal from a religious talk station based out of Colorado.
I live in Saint Louis Missouri. I have heard AM stations from 42 states over the years, all the way from California to Massachusetts. I have kept the log book of what I've heard. Yes, I'm a geek.
I thought at first this referred to phase modulation (I’m an engineering student) but then I realized this refers to pm the time and it made the pun that much worse for me and made me feel kinda dumb
I'm Venezuelan and I live in the central coast. During last month's blackouts I realized my car picked up an AM radio station from New York that I later identified as WCBS 880 and I was really really really puzzled about it, because I didn't understand how in heavens could I listen to the same thing that people in NYC were listening to. Thanks for explaining why, I can rest easier now.
MoutainMan3000 One type of radio navigation aid is essentially an AM radio that can tell the direction to the transmitter. Their communication radios use higher frequencies closer to those for FM broadcasts.
It uses different frequency, planes use high directive antenna so that they can pick up only the freq they need to recieve. But even with that, some interfernce still occurs.
Actually they do, however it is at a frequency of 108 MHz to 137 MHz, right above the FM broadcast band. It is the frequency that determines propagation so bounce isn't an issue. The modulation (AM vs. FM) affects audio quality, so pilots don't get as clear reception as an FM signal would.
I remember when I was a kid and had an old 'ghetto blaster' stereo with one of those old school retracting antennas on it. I found that at night, and with some strategic placement of aluminum foil on the antenna, I could pick up WGN radio in Chicago, the aforementioned KOMO 1000 radio from Seattle, KNX 1070 in Los Angeles, and an AM news radio station from Vancouver, Canada. Mind you, I was living in Billings, MT at the time. I thought it was kinda cool getting AM stations from all over the country.
Even wrong information is useful as there's usually a correction in the comments. Knowing what the wrong info is is important. Sure, when correct info is given there's often a mis-correction following. Some info is wrong but is good enough. Newton was wrong but his physics was close enough for almost everything. KE = 1/2 MV^2 but in Einsteinian atomic physics E = MC^2. We're now finding out that Einsteinian physics is a little off but it, again, is good enough for way past Newton.
I slash a big shallow cut or I can aim for something important like a lung or the heart. The rib cage does this funny thing of keeping the gibbly bits, that let you live, safe in one place
More. If a killer, whether defender or murderer, does stabbing only, more wounds means more leaks. Um, what does this have to do with AM waves and FM carrier waves?
Perhaps too technical for your target audience, but you failed to mention that many AM stations, rather than signing off or drastically reducing power, shift to directional antenna patterns after sunset. I worked in broadcasting for a few years in the early ‘70s. The first place I worked was a small town AM & FM outlet, WCOR in Lebanon, TN. They were 1000 watts on AM and 10,000 watts FM. At sunset, the AM shut down and the FM continued. They simulcast, broadcasting the same content on both transmitters. Later I worked for WLAC in Nashville. Their AM & FM were separate operations. The FM at 105.9 MHz broadcast 24 hours with 100,000 watts ERP. The AM was 50,000 watts at 1510 KHz. Both were the maximum legal power for U.S. stations. At sundown the AM shifted to a directional pattern, oriented north/south if I remember correctly. Another Nashville station, WSM at 650 KHz, broadcast 24 hours with their full licensed 50KW and an omnidirectional pattern. The power and reach of WSM, “clear channel 650,” is one of the reason the Grand Ole Opry, and country music in general became so popular. A bit of radio trivia for you. Did you know that WLS 890 KHz in Chicago was started by Sears, Roebuck and Co. to encourage people to buy radio receivers? The call letters were an acronym for Sears slogan, the World’s Largest Store. Mid-1920’s editions of the Sears catalog contain full page ads for WLS opposite the page selling radio sets.
the chicago am 1000 station is not KMVP, it is WMVP. This is because all stations east of the mississippi river start with a W, and every station west of the mississippi start with a K.
Welllllll...that's mostly true, but not all. KDKA in Pittsburgh and KYW in Philadelphia are a couple of notable exceptions to this rule. So are WOAI in San Antonio and WBAP in Fort Worth. From WOAI-AM's Wikipedia article (emphasis and parenthetical info by me): Because it went on the air in the earliest days of broadcasting, the station's call sign begins with a "W." Stations in Texas were in the W territory before 1923, when the dividing line became the Mississippi River. From that point, nearly all stations in Texas received "K" call letters. But WOAI has been grandfathered (exempted) with its unusual call sign. And when it added a TV station, it was given the WOAI-TV call letters. Even though Channel 4 is no longer co-owned with WOAI Radio, it has kept its W call sign...WOAI and WOAI-TV are currently the westernmost stations to have "W" call signs (in the continental U.S.; WVUV-FM in American Samoa, a U.S. territory, is the actual westernmost station in North America). There are still about two dozen W stations in states west of the Mississippi River.--So as you can see, radio stations existed before the rule change in 1923 brought a little more order to call sign assignments. I will add that some stations in close proximity to the Mississippi River may receive exceptions as well.
@@marksymbala3454 If you mean smoke,no I do not and I don't see the relevance of the question. I just deleted a similar post. Have a wonderful day,sir.
AM is capable of comparable sound quality to FM under the right conditions there is also an AM stereo broadcast standard (though it came so late it has very poor adoption). There are 2 factors that normally limit AM audio quality Bandwidth and noise. Bandwidth comes down to transmitter and reciever design and use. Prior to the 70's AM was the major music medium and there were AM stations with better fidelity and bandwidth than FM stations...An example of this is WLW which after the FCC told them you "can no longer transmit at 500KW as the world's strongest AM station" decided "if we can't be the strongest then we'll be the highest fidelity"...HH Scott certified their AM station as having better fidelity than most FM stations at the time. Most stations and radios used on AM today are expected to be used for talk radio which prompts many stations and receivers to limit bandwith and fidelity to land-line phone like lousiness for cost savings. FM has the advantage of being mostly immune to RF noise. Most RF noise is more of a varying amplitude impulse than a varying frequency so FM recievers are basically designed to ignore it (called capture ratio)...FM recievers also tend to ignore whichever station has a weaker signal...So unlike the AM band the FM band will have closer spaced stations that effectively interfere with eachothers geographical outer fringe coverage...Case in point ever listen to FM on a long road trip and after a moment of noise (say while cresting a hill) suddenly your hearing a different station despite not changing the frequency?...That's capture ratio in action. In the last 20-30 years switchmode power supplies have become more prevalent (in every device you plug in) and those tend to be basically huge RF noise polluters and tend to disproportionately affect AM because of AMs lower frequency. A switchmode supply usually creates (and doesn't bother to contain) a 17KHz square wave...And if enough of my college electrical engineering Fourier analysis class is still with me, a square wave consists of a STRONG sine wave at its fundamental frequency (in this case 17KHz) and an infinite series of harmonic (read that multiples fo the fundamental) frequencies above that (for example 34KHz, 51KHz, 68KHz, etc all the way up to infinity Hz ) and as the harmonic frequency decreases its intensity decreases so a 17KHz CFLor phone charger, or computer power supply, etc will generate louder RF noise in the AM and frequencies than at the FM band frequencies. A final mind blower to some people: AM and FM are just interchangeable techniques to place audio on an RF carrier...So you could modulate an RF signal in the AM band with FM modulation or an RF carrier in the FM band with AM modulation....In fact in the Ham radio world, there are frequencies that are/have been used interchangeably with AM or FM modulation.
Nothing changes the fact that AM BW is limited by the FCC at 5kHz max while FM is 15 kHz, noise be damned. AM will never surpass FM fidelity. Maybe *at the time* WLW was better but not now.
WABC 770 AM in NYC was always on my sister’s car radio when I was a kid growing up in the early 70’s in Connecticut. After we’d moved to Pittsburgh in 1981 I put a TV antenna atop the back porch of our house and connected it to my AM/FM stereo receiver. I did it to get better local FM but I was stoked to discover that at night I could pick up WABC in NYC. I thought it was the coolest thing to get that familiar signal from 400 miles away.
WABC operates a single tower omnidirectional station at 50kW from Lodi, NJ--about a mile away from Tony Soprano's "Badda Bing" strip club filming location (Satin Dolls, in Lodi).
I like to listen to WSM in Nashville, though I live in Louisiana. I've spent many warm summer nights on my back patio with just a radio and a bottle of beer, listening to the music while staring up at the stars. More recently I've been having fun tuning into distant shortwave stations.
There's a station based in denver that runs on 850khz (850KOA) that is nicknamed the "blowtorch of the rockies". It is so ludicrously powerful to get through all our mountains that it can be picked up in Siberia.
As this video just explained, AM signals bounce off the ionosphere at night, and carry for great distances. The Rocky Mountains have no impact on a 50kW AM signal like KOA. The mountains DO have a huge effect on Denver’s FM stations however, since their signal waves do not bounce.
As a kid in Minnesota in the 1980s I discovered that at night I could regularly tune in KOA from Denver and WLS from Chicago, and occasionally I even picked up WOR from New York, and over the years I learned about 'clear channel' (lowercase) stations, but I don't think I really understood *why* they were stronger at night until I watched this video today.
FYI - There’s a mistake in the narration starting at 01:44. After he shows the green lines going upward and correctly says “the FM waves go right through (the ionosphere”), the RED lines that appear represent an AM signal but the narrator inadvertently refers to it as an FM signal. Indeed it is an AM signal which, at night when the lower level ionosphere dissipates, the AM signal bounces off the upper level ionosphere and can travel a much longer distance.
I’ve always wanted to start a radio station that plays Video Game music unfortunately I learned about copyright later in life and my dream may never become a reality. :/
I don't know how it's like where you are, but where I am radio stations simply pay a fee to an organization and can then play whatever they want. That organization then distributes money to the copyright owners according to how much their stuff has been played. So what I'm saying is it might be easier than you think.
Close but no cigar. The ionosphere does play a major part in this, however it's the lowest layer, called the D-Layer, that makes it possible. Or rather the *absence* of the D-Layer. At sunrise the D-layer forms and lower frequencies are absorbed by it, so the station remains ground-wave only and covers the local listening area. At night the D-Layer disappears and the signals can get to the higher layers of the ionosphere where they bounce back to Earth. Also, most AM broadcast stations operate directional arrays changing pattern at daybreak and twilight.
Here in Brazil, a former radio station used 10 kW at day and 1 kW at night, with their transmissions reaching almost the same distance (slightly better at night, of course). The transmitter operator always received a letter from a government agency with a schedule indicating the precise time to change the transmitters along the year to avoid conflict with another stations from the region.
Back in the 60s, in my teens, I had a hobby of tuning for, and catching am radio stations at night. There used to be a LOT more of the "clear channel" stations than there are today. A few years ago the FCC removed a bunch of the 50,000 watt clear channel stations from being "clear channel". If you sent a letter/postcard to most of these stations, reporting what you heard and the time, they'd send you a return postcard, known as a QSL card, proving you heard that station. I had quite a collection of these cards, with the farthest away station I received being KDKA in Pittsburg PA, with me being in San Diego CA. That station was somewhat of a hard one to get as there was another station on the same frequency in Los Angeles. What it took to catch KDKA was, the LA station would go off the air late sunday night-early monday am for maintainance and one early monday morning I caught KDKA. KDKA is better known as the first actual commercial radio station in the US, on Nov 2, 1920.
I'm pretty sure that the channel in Chicago is not "KMVP", since that call sign is for a station in Arizona (that recently switched from AM to FM. Also, radio stations broadcasting from East of the Mississippi all begin with the letter "W" (For the most part, there are a few exceptions like for instance in cities that straddle the river like the Twin Cities in Minnesota, which use "K" even if the tower is on the East side of the river, like for instance KSTP in St Paul, which I used to live across the street from)
WMVP is a broadcast radio station in Chicago, Illinois, United States, providing Sports News, Talk and Live coverage of sports events as the flagship station of the Chicago Bulls.ESPN Network.
As I am old (40+), I remember playing with my radio and the antenna some nights as kid, trying to pick up radio stations from as far away as possible. Past AM, you move into SW, MW and LW (short, medium and long wave) territory... but thats another story for another time or for a doomsday scenario.
InsaneGamers, I can sometimes pick up a German AM radiostation. The last Russian am radiostation was shut down 3 years ago, a shame, really, now geologists, meteorologists, hunters and etc. have nothing to listen too.
2:36 Wrong. The AM band starts at 530 kHz, but that frequency and 1610 kHz is only used for traveler information stations. 3:16 WMVP not KMVP. Chicago is located east of the Mississippi River. Stations east of the river have callsigns that begin with W, whereas stations west of the river have callsigns that begin with K.
2:20 this is completely true, I work for a AM station in Boston and someone got our signal in Norway and sent us a audio recording a couple months ago.
I learned about this from Lost. Sayid tells Hurley that the sound they’re hearing from the radio is from really far away and bouncing off the ionosphere.
Excellent video as always, but I noticed a little mistake. There is no station called KMVP in Chicago, but there is a station called WMVP. Generally in the US, stations west of the Mississippi have a call sign starting with K (although there are some exceptions like WFAA in Dallas) and stations east of the Mississippi have a call sign starting with W (there might be some exceptions, but I'm not sure).
I am a native of the Chicago area and never knew AM 1000 had the WMVP call sign! I only remember it as WCFL back in the day when it was a rock station! LoL.
What isn't mentioned is, just like propagation (or skip) with CB and HAM operators, people outside the line of sight but not along the outer edge of that circle may not even know that station exists because the signal passes right above them while bouncing.
30-40 mile range for FM? I've picked up FM radio in my car from 60-70 miles away from the tower. Apparently 103.5 BOB-FM Austin has a big antenna (like 1200 ft) and the place I got it from that far away is around 150 ft lower in elevation
Truth is, it depends. HAI generalized a lot so his vids could be more on topic. The average station usually makes it 80-90 mi if one is willing to put up with some static. If you go up on a local hill or mountain, the range now becomes 120 mi. It's all about line of sight. Also, Tropo can increase this range even further.
Huh. This explains a weird thing that happened when I was a kid. My grandparents live ~12 hours away from me and I spent many hours in the back seat of a car riding to and from their house. One time as we were returning from their house, we were flipping channels on the radio and were able to tune in to their local talk radio station some 600+ miles away.
I presume this is why one of the largest companies that own an operate radio stations is called "Clear Channel Communications". Even though most of their stations are FM, naming the company after the most powerful and highest status AM stations is definitely a power move.
Informational but super simplified. AM and FM are only modes and have very little to do with propagation. As for the FM sounding better because of the higher frequency, that in itself real doesn't have much to do with it. It has to do with the mode. Wide FM takes up over 100kHz of bandwidth, while an AM station is only 1/10th that. As far as the distance AM signals travel during the day, there is also a lower layer of the ionosphere that absorbs RF energy with wavelengths generally below 10Mhz during the day, but is one of the first layers to dissipate around sunset. Its all a lot more complicated than a short 5 minute video can address, but it gives the general gist of it.
I don't know if this is a normal occurrence, but I was able to pick up WJR 760 AM out of Detroit all the way from Rochester, NY, through Western Pennsylvania and the entirety of Ohio, all the way to Indianapolis, IN, during a drive during daylight hours. Of course if you look at a map during that journey you are never super far from Detroit, but still that is pretty impressive.
Yep, if this was in the winter, stations come in well before sunset, since that "D" layer doesn't build as much. Same thing in reverse after sunrise. I had a couple of 600 mile stations close to noon locally.
When I was a kid, a friend gave me a large console tube radio from the 30's. I was able to get it working and found new tubes for it, built a high gain antennaand started listening. I was able to get Radio MOSCOW from Long Island.
Um, that was an extremely confused explanation of radio wave propagation. AM and FM are techiques to modulate ("add sound to") a radio signal. It doesn't matter if the freequency is 1000 kHz or 100 MHz, you can modulate both with AM or FM. If you [break the rules and] modulate a 1000 kHz transmitter with an FM signal, then you would experience exactly the same radio wave propagation as you do with the usual AM broadcasts on the same frequency. It will be the same thing at 100 MHz; where the signal propagation won't change because you switch between AM and FM. What does matter for the radio wave propagation is the frequency (or the wavelength if you prefer using that) and how it interacts with the atmosphere, mainly the ionosphere, and how that, in turn, is affected by radiation from the sun.
FM radio isn’t only line of sight. That is an old wives tale. I’m originally from Hartford, Connecticut and can remember back in high school I used to routinely pick up FM stations from New York City and Boston, Massachusetts which are both just over a hundred miles in either direction from Hartford. My favorite stations were KISS 108 (WXKS 107.9) in Boston and the now defunct KISS FM (WRKS 98.7) in New York City. I could also pick up WBLS 107.5 in New York City. When my brother went away to college. He went to Purdue University, which is in West Lafayette, Indiana. That is about a hundred miles outside of Chicago. He used to pick up the now defunct WBMX 102.7 as well as WGCI 107.5 on the regular on his boom box and record their house music mixes on cassette and bring them home.
I thought I was the only one with this experience. I remember back in Winnipeg MB we could pickup FM stations from as far away as Fargo ND which was about 220mi away.
*Farther Further is only used for non-literal descriptions. "Getting a good education can help further your career." Farther is used when you are talking about physical distance.
Living in Chicago, I have to make a correction to this video. At 1000 am, the radio station is actually WMVP, which is ESPN. KMVP is actually Arizona sports radio. Just letting you know!
For a few minutes, night time reception prevailed; but remember, it's day or night in the AREA OF THE BOUNCE that counts; so radio stations and listeners AT EQUAL DISTANCES AND OPPOSITE HEADINGS FROM THE CONE OF TOTALITY are briefly connected, NOT stations or listeners IN the cone of totality.
Allan Richardson I am confused with you trying to highlight too many of your words with capitalization. The previous comment didn't specify anything, OP just wanted to know what happens to radio stations during a solar eclipse.
MischievousMoo Sorry I can’t use italics or bold or underlining in this app. After rethinking the matter, it may not be worth computing the effect of an eclipse on radio wave reflection, since the darkness is so short. The transition from night to day and day to night are slow and gradual, giving time for ions to form or neutralize. An eclipse takes much less time. If anyone has actually had a radio contact during an eclipse on a frequency and over a distance that would normally only be possible at night, they can post their experience or a reference to any data that may have been published. In any event, the eclipse would have to be passing a point halfway between the two stations, not the location of either station. Meteor scatter works the same way, but that’s another story.
This is very important for people who work out in the open ocean, as one the ways of sending a distress/safety message is using HF equipment (basically AM). We work out a distance to a coast station, from that we know the frequency to use. For 500NM it’s 8kHz, but if it’s night it’s 4kHz. So it’s important to always remember this, as the last thing you want is for your mayday to bounce miles away from station you wanted to get in contact with.
and thats why the world is switching to DAB+, also can you do a vid on the naming of us radiostations? the names seem a bit wheird to me as a european.
Kars Noordhuis most of the characters mean nothing, but the first letter will tell you location. The division here is the Mississippi River. To the west, you’ll find stations that start with K (KOMO KTAR KIIS KJZZ KSLX), and to the East you’ll find W and Z (Z100 WPLK WVLM).
Mystery Man Z100 is a name for WHTZ, among others (there is/was also a Z100 in Portland, Oregon). Z is primarily assigned to the UK & Brazil by the ITU.
From an radio frequency engineer's point of view I think your video here is pretty good, however there is one issue I have with it. You can be left with the impression that AM radio signals go further because of the mode of transmission, this is not the case. The propagation of the radio signal is purely based on frequency (and consequently it's wavelength) and not the mode of operation. In theory there is nothing (except licencing) to stop you transmitting an FM signal on 1000kHz (or 1MHz as I would prefer to say), and this would travel as far as an AM signal would do. And the opposite is true too, there is nothing stopping you transmitting an AM signal at 100MHz. In fact this (almost) happens as the aircraft band 108-137MHz uses AM as it's mode of transmission. But overall you have a good video that the general public will understand and enjoy :)
You've left out a LOT of important details! KOMO and WMVP (not KMVP) are both directional Class A, but they both use directional antenna arrays at night (KOMO actually provides a signal with more than 50,000 effective watts, but almost no signal to the West, WMVP (not KMVP) sends it's power eastward, in fact, WMVP actually bought billboards in Detroit to advertise Bulls basketball when the Bulls dominated the NBA. They send almost no signal westward at night. The coverage of seemingly similar AM stations can vary drastically. A 5,000 watt station in North Dakota, near the bottom of the band, can carry through ND, SD and a lot of Saskatchewan, whilst a 5,000 watt station in Georgia at the top of the band may only go out to 15 miles. Most of the regional channels were given out on a "first come, first served" basis, the first station on the channel will have good coverage, every other station on said channel tolerates the first station's interference, and has to build an expensive directional array so it doesn't affect the "senior" station. You'll know an AM station is directional by seeing more than one tower (as many as twelve!) at its site. Also, there are six "local" channels (1230, 1240, 1340, 1400, 1450 and 1490) where Class C "local" stations are 1,000 watts all day and night. By day, these stations go out as far as the soil under the station can carry the daytime signal. If you look up the FCC's "M3 soil conductivity map", you'll get to know which local stations have good or bad daytime coverage (at night, all of these stations interfere with each other, leaving only their small town with a good signal) For what it's worth, there are cases where FM stations can be heard FAR beyond the line-of-sight. Often, an "air inversion" can "trap" an FM signal into following the curve of the earth (most often observed late at night or early morning). This is particularly true over lakes and oceans. Sporadic-E skip will sometimes reach the FM broadcast band. It is not as common as it is on the 6m amateur band or TV Channels 2-6, but it is a true ionospheric skip mode, allowing FM reception from stations about 1,000 miles (1,600km) away, and not the stations between your site and 700 miles. Look for it late May through early August, in late mornings and around sunset.
If the circumference of Earth was 25,000 miles, it would calculate to a curvature of .75 x #miles squared; which means that for a FM radio signal to reach 35 miles the transmitter tower would have to be over 900 feet tall, as tall as the Empire State building in NYC. DO YOU SEE ANY RADIO TRANSMISSION TOWERS AS TALL AS THE Empire State BUILDING?
The Empire State Building is already a radio tower. Most transmitters are placed on tall buildings in the city in the US, so they don't have to make the tower so tall. Also: The empire state building is 381 metres tall. Bilsdale transmitting station in the UK is 314 metres tall. Emley Moor is 330 metres tall. So yes, I have seen them get that big.
900 FT? No the Empire State Building is 1200 FT high, and that's not including the antenna on top which gives the overall building a height of 1400 FT.
OK, smart guy, how about this: for the Earth to have a spherical circumference of 25,000 miles, and curvature of .75 x miles squared this would calculate to .75 x 50 x 50, or 2500 x .75, which is 1875 feet of curvature over 50 miles. The new 'freedom' tower in NYC is 1776 feet tall, so for radio transmission signals to cover America, it would require one tower every 50 miles as tall as the 'freedom' tower. Now, DO YOU SEE A RADIO TRANSMISSION TOWER AT LEAST 1875 FEET TALL EVERY 50 MILES? YES, OR NO?
"Much like a stab wound" LOL, this channel is one of the best I have ever seen. You make the boring stuff from a textbook seem WAY more interesting. You have a great talent, and I love your dry sense of humor. Keep up the good work.
Why doesn't a single buyer just buy up all the channels on a given frequency? That way during the day they can customize programming to the area and at night they can just broadcast some common programming everywhere? I get that there are clear channel broadcasters but I'd imagine there would be some synergies here that a single owner could exploit.
When you mentioned KMVP in Chicago, didn't you mean WMVP? Because Chicago is east of the Mississippi River, and all call signs east of the river begins with W. I bring this up because I live in Phoenix, Arizona, and we have a radio station with the callsign KMVP.
Nope. He meant 'FM'. Listen to the two sentences before that one. Basically, AM can bounce off the ionosphere, so it doesn't need direct line of sight. But "without the bounce" (because it doesn't bounce off the ionosphere), FM can only cover in line of sight (ignoring things like most buildings and trees, since FM can generally penetrate those, but not the earth itself).
In the old days those were called "Daytimers". They had to go off the air at sundown to avoid interfering with stronger stations in larger cities. Daytimers were only in small towns. KNGS 620 in Hanford, CA had to go off the air at night to avoid interfering with KFRC 610 in San Francisco, 150 miles away.
I had no idea AM radio was still a thing? I don't think I've heard any AM radio for decades. In my country FM radio is also dying out, we're switching to digital radio (DAB+)
If you are doing 'science talk' don't equate broadcast mode with frequency band. I know that's how the bands have long been referred to in the US, and we in the UK eventually adopted it because of imported japanese radios, but it's wrong!
If you want to hear what it would be like if every station transmitted full power around the clock, tune in to a “graveyard” frequency at night: 1230, 1240, 1340, 1400, 1450, 1490 kHz!
I screen shotted this comment I’ll try those frequencies tonight. I’d imagine it sounds like you’re sitting in a full restaurant people talking all at once glad FM don’t have this problem
@@kevindavis4709 thanks to the capture effect, and that VHF waves mostly pass through the ionosphere! But, every now & then you get tropospheric ducting on VHF, and that’s fun!
Given the population density in rural America, low-bandwidth & high-distance channels like news, sports, traffic are good to have in AM radio. for music and local stuff you would use FM stations. Also, thousands of AM stations in such a large landmass is not very significant.
I live in Phoenix, and I can pick up AM stations from as far west as Los Angeles and San Francisco, as far north as Denver, and as far east as Dallas-Ft. Worth.
AM frequencies can also bounce off water. So you can get cases where it hops into the atmosphere, off the ocean (or lake), back off the atmosphere, etc. and gets half way around the planet. In the military, we'd occasionally tune in our HF into a local AM station for music. Half-hour later, you could hear a faint signal, re-tune it a few hundred megahertz and you'd be listening to an Iranian station. You could often guess the station by where it was dark at the time of day you are hearing it and eliminating languages you could identify. We had a big chart of world stations which could finally tell you who it was.
If I may ask, were or are you in the Navy?
@@olafelsberry420 No. Summer job in the Canadian militia with a radio communications trope. Just a large AM receiver in the back of the truck along with smaller VHF units. We'd often tune the HF to some AM radio station and listen to music while up all night while doing exercises on the VHF units. You just had to make sure you didn't grab the wrong mic when answering or else everyone in 50 miles listening to the local radio station could hear you. Fun times.
Same for FM, will bounce to, same as AM
@@VicGreenBitcoin Not so. AM is from 500 to 1,700 kHz, FM 88 to 108 MHz. Both will bounce off water, but FM is scattered more by water (i.e. clouds, rain, or humidity) and most importantly shorter wave lengths are not reflected back by the ionosphere. On a raining day, VHF radios really suffer in range while HFs far less effected. For bouncing, both with bounce off a large body of water. However, VHFs go off into space while HFs will bounce back from the upper atmosphere. Hence why we could detect an Iranian radio station bouncing a half-dozen times off the upper atmosphere and oceans. We never detected VHF radio signals at any long distance while HF often had odd background interference from distance sources.
@@BW022 No, AM and FM are not necessarily set by frequency . You can talk perfectly on 1700kHz on FM if you set the receiver on FM to (Most normal radio receivers have not that option). Also you can perfect modulate Am on 88 to 108 Mhz band, remember just a little higher on 118 Mhz air-planes use AM. So its not the AM that makes the skip trip...just saying
"The Earth supposedly curves" XD
Checkmate, round earthers!
and "the much loved FCC"
“If you want a surefire way to make your millions, you should start a radio station.”
But... the sad thing it does. 2 questions for the flat earthers. 1 why would NASA and the government lie, and 2 because of that layer in the video, and the fact it's curved, the radio waves go farther. It works on a flat earth but not when the wave is curved. Also, if the earth is flat, does it spin? Does it move? Does it have gravity? And is it in space?. Answer all of these questions please.
Brendan Nichols I think you took that wayyyyy to close to home...
I was simply commenting on his sarcastic use of "supposedly"...
I'm well aware of the spheroid nature of the Earth.
2:35 "Much-loved FCC"
Forest Bird the best part is how data on the internet is no longer treated equal because of them.
Aka the Air-Wave Police xD
@@BillAnt "F**k the airwave police!"
I always have to think about the Family Guy Song "Freaking FCC", when I hear FCC
Because it's AM duh! You'll need PM station to listen at night
*Taps head*
Gold! Comedy comment gold here.
hey, I still can't listen to it after midnight! I call rip-off!!
Glorious
a
"With wavelengths, much like stab wounds, smaller is better."
That pun really left me hangin'
+Tesser 4D That's not a pun.
What's a radio? Is that kinda like a podcast?
You should upload more
CrazyFace, Inc. Of course he is
+AwesomeGuy , I'm putting up a video for the Project for Awesome (hopefully tomorrow). I have a full-time job though, so my uploads for now will remain mostly every 2-3 weeks.
FutureNow :( alright. Great channel, though
Hah.
You and Wendover Productions should make podcast and pretend to be the same guy. It will blows people mind, you guys sound alike.
SierraLima Congratulations, that's the joke.
I think they were kidding...
Weird TH-cam Name HAI is like the more sarcastic alter ego of WOP no? :P
Shaunak De More like savage millennial cousin.
SierraLima That is why the the original comment said "pretend". Read thoroughly next time.
KOMO in Seattle is correct, but for Chicago it’s WMVP for our radio station. All radio stations in the US are split by prefix along the Mississippi River. K to the west, W to the east.
Not all of them. Older stations are "grandfathered," i.e. KQV and KDKA in Pittsburgh, east of the Mississippi.
Not all. I.E.: KYW in Philly. KDKA in Pittsburgh.
@bcubed72 you're right, but it's still WMVP for AM 1000 in Chicago, which is what his main point was.
WHO, Des Moines, is West of the Mississippi. Another Grandfathered example, and a 3-letter one at that!
Came to say the same.
0:54 jesus fucking hell man, metaphor of the year
deadasfak I had to go back to that, he is getting dark!!
It's actually a similie
Damn, I thought they're mammograms
deadasfak mammograms?
That's not a metaphor. Metaphors state one thing is another thing. Not "like" another thing.
"Earth is 'supposedly' curved" lol you're savage
edit; wow thanks for the likes. i opened up this comment after 2years and saw 1.9k likes. wow!
Dodges FE rants like Neo.
GHUMAN THE BAND Half as Interesting is more Sarcastic than Wendover Productions. I like It :V
+Stephen Waldron At 01:47, I think he meant to say AM, but, you said FM instead
Vijaya Teja Rebbapragada I don't think so. He said "Without the bounce", which is indicative of FM, and was explaining how FM radio has the drawback of reaching a shorter distance than AM day and night. AM frequencies on the other hand, reach further than FM during the day, and significantly farther still at night, due to the bounce off the ionosphere.
As for the curvature bit, he was saying that the curvature was considered in the calculation. On a Flat Earth, the range of FM radios would be significantly larger as there would be an infinite line of sight to the tower, the only consideration being the barriers in the way, including skyscrapers, mountains and as FEers would be quick to point out, the air itself, that would scatter the signal over distance.
Vijaya Teja Rebbapragada
No, it's clearly meant to be FM, it just tells us the range difference between AM (~~150 km radius) and FM (~~50 km radius).
[just for clarification, this means FM waves from one station can be picked up in an area of ~8.000 square Kilometers, while AM in an area of ~70.000 km {which is roughly the size of Ireland, if my memory serves me right}]
"Learn how to think"
Oh thank god, I need this.
I do too
Just a disguised ad hominem attack. Can't refute? Demean the intelligence of the opponent.
One night, during a vacation in the US, I remember waiting in the car for our parents who were visiting with family (listening to old people talk gets boring, obviously). We decided to turn on the AM radio. We were able to pick up two or three stations conflicting with each other. It kind of sounded like they were arguing too. So that was entertaining.
Aslo it happens to fm too aslo I had that happen to me but with fm it usually starts bleeding near one of my neighbors houses or car
0:54 That's an interesting comparison 🤔
Capitalist Roope what does he say? I can't understand the word. English isn't my native tongue
OnlineAcc
"but with wavelengths, much like stab wounds, smaller is better..."
Gee, I heard that and thought the opposite: "No, a LARGER stab wound is better [at stopping a bad guy]." I guess it depends if you see yourself as the stabber, or the stabee!
bcubed72 Well that's not terrifying.
+Haiku Metzger
How is being able to defend one's self from an assailant terrifying? There's nothing immoral about self-defense.
In the last week of November 1994 I picked up an AM radio signal late at night being broadcast from Denver, Colorado while driving in Southern Illinois. The station identified itself as "The Blow Torch of the West".
I picked up a German radiostaion when I was 200km to the east of the eastern border of Finland.
Every night, I can pick up KSL News Radio (1160 AM) from all the way in Boise, ID. they are based in Salt Lake City, UT. I also once picked up a signal from a religious talk station based out of Colorado.
NorthernChev That would be AM 850 KOA. I live in St. Louis, and can confirm that it's still active.
MrPaukann so you were in Russia?
I live in Saint Louis Missouri. I have heard AM stations from 42 states over the years, all the way from California to Massachusetts. I have kept the log book of what I've heard. Yes, I'm a geek.
Video killed the Radio Star
The Buggles
In my mind and in my car
And MTV killed the Video Star
*OH, OH OH OH*
The internet killed the video star
As an engineer in the commercial broadcast sector I must say this was a very well done explanation!
Much loved FCC lol xD
At least their symbol (should I call it trademark?) looks cool in almost all of my devices
Fuck the FCC and fuck Ajit Pai
Disband them!
what a slimy pie
I hate the FCC after they ended net {pay 9.99 to your internet provider to see the rest}
Its because they don't turn into PM waves.
I'll see myself out.
bleh mehm This right here. The real reason
I thought at first this referred to phase modulation (I’m an engineering student) but then I realized this refers to pm the time and it made the pun that much worse for me and made me feel kinda dumb
A Bite-Sized Taco Thank you for that. I just got my ham license recently and studied phase modulation, so the joke flew right over my head.
bleh mehm i was gonna make that joke, you sucker
it's funny because there's actually a modulation named PM.
*”Earth is supposedly curved”*
*Wait a minute... -.-*
I noticed that too
Thought the same
Depends on what is meant by "earth." Anyone can see that "the" earth is neither flat nor round (spherical). Mountains for example.
I'm Venezuelan and I live in the central coast. During last month's blackouts I realized my car picked up an AM radio station from New York that I later identified as WCBS 880 and I was really really really puzzled about it, because I didn't understand how in heavens could I listen to the same thing that people in NYC were listening to. Thanks for explaining why, I can rest easier now.
But where are the airplanes? Do airplanes use AM signals?
MoutainMan3000 One type of radio navigation aid is essentially an AM radio that can tell the direction to the transmitter. Their communication radios use higher frequencies closer to those for FM broadcasts.
It uses different frequency, planes use high directive antenna so that they can pick up only the freq they need to recieve. But even with that, some interfernce still occurs.
Yes, as a matter of fact.
Actually they do, however it is at a frequency of 108 MHz to 137 MHz, right above the FM broadcast band. It is the frequency that determines propagation so bounce isn't an issue. The modulation (AM vs. FM) affects audio quality, so pilots don't get as clear reception as an FM signal would.
Wrong channel, that's Wendover
I remember when I was a kid and had an old 'ghetto blaster' stereo with one of those old school retracting antennas on it.
I found that at night, and with some strategic placement of aluminum foil on the antenna, I could pick up WGN radio in Chicago, the aforementioned KOMO 1000 radio from Seattle, KNX 1070 in Los Angeles, and an AM news radio station from Vancouver, Canada.
Mind you, I was living in Billings, MT at the time. I thought it was kinda cool getting AM stations from all over the country.
"In this video you might actually learn something"
I always learn something from these videos
Double as Interesting?
Even wrong information is useful as there's usually a correction in the comments. Knowing what the wrong info is is important.
Sure, when correct info is given there's often a mis-correction following.
Some info is wrong but is good enough. Newton was wrong but his physics was close enough for almost everything.
KE = 1/2 MV^2 but in Einsteinian atomic physics E = MC^2. We're now finding out that Einsteinian physics is a little off but it, again, is good enough for way past Newton.
But what about TC?
(Toyota Corolla)
Wrong channel xD
Here we'd need PM (Plane Modulation)
if you have to put it in paranthesis why bother shortening it
Patsonical Crossover episode
Sebastian S am/fm/tc get it?
Darth Guilder This isn’t RealLifeLore, my friend.
What's with that statement? Aren't bigger stab wounds better if you're doing the killing?
*EDGY*
No seriously the edge of the knife is too sharp i'm dying
I slash a big shallow cut or I can aim for something important like a lung or the heart. The rib cage does this funny thing of keeping the gibbly bits, that let you live, safe in one place
Don't cut yourself on that edge
More. If a killer, whether defender or murderer, does stabbing only, more wounds means more leaks. Um, what does this have to do with AM waves and FM carrier waves?
"Much-Loved" FCC
Gtfo
Perhaps too technical for your target audience, but you failed to mention that many AM stations, rather than signing off or drastically reducing power, shift to directional antenna patterns after sunset. I worked in broadcasting for a few years in the early ‘70s. The first place I worked was a small town AM & FM outlet, WCOR in Lebanon, TN. They were 1000 watts on AM and 10,000 watts FM. At sunset, the AM shut down and the FM continued. They simulcast, broadcasting the same content on both transmitters. Later I worked for WLAC in Nashville. Their AM & FM were separate operations. The FM at 105.9 MHz broadcast 24 hours with 100,000 watts ERP. The AM was 50,000 watts at 1510 KHz. Both were the maximum legal power for U.S. stations. At sundown the AM shifted to a directional pattern, oriented north/south if I remember correctly. Another Nashville station, WSM at 650 KHz, broadcast 24 hours with their full licensed 50KW and an omnidirectional pattern. The power and reach of WSM, “clear channel 650,” is one of the reason the Grand Ole Opry, and country music in general became so popular.
A bit of radio trivia for you. Did you know that WLS 890 KHz in Chicago was started by Sears, Roebuck and Co. to encourage people to buy radio receivers? The call letters were an acronym for Sears slogan, the World’s Largest Store. Mid-1920’s editions of the Sears catalog contain full page ads for WLS opposite the page selling radio sets.
the chicago am 1000 station is not KMVP, it is WMVP. This is because all stations east of the mississippi river start with a W, and every station west of the mississippi start with a K.
Welllllll...that's mostly true, but not all. KDKA in Pittsburgh and KYW in Philadelphia are a couple of notable exceptions to this rule. So are WOAI in San Antonio and WBAP in Fort Worth.
From WOAI-AM's Wikipedia article (emphasis and parenthetical info by me):
Because it went on the air in the earliest days of broadcasting, the station's call sign begins with a "W." Stations in Texas were in the W territory before 1923, when the dividing line became the Mississippi River. From that point, nearly all stations in Texas received "K" call letters. But WOAI has been grandfathered (exempted) with its unusual call sign. And when it added a TV station, it was given the WOAI-TV call letters. Even though Channel 4 is no longer co-owned with WOAI Radio, it has kept its W call sign...WOAI and WOAI-TV are currently the westernmost stations to have "W" call signs (in the continental U.S.; WVUV-FM in American Samoa, a U.S. territory, is the actual westernmost station in North America). There are still about two dozen W stations in states west of the Mississippi River.--So as you can see, radio stations existed before the rule change in 1923 brought a little more order to call sign assignments. I will add that some stations in close proximity to the Mississippi River may receive exceptions as well.
Kdka pittsburgh
Wow- I just posted the same thing-guess I have to delete it. LOL.
@@PC4USE1 do you smok
@@marksymbala3454 If you mean smoke,no I do not and I don't see the relevance of the question. I just deleted a similar post. Have a wonderful day,sir.
AM is capable of comparable sound quality to FM under the right conditions there is also an AM stereo broadcast standard (though it came so late it has very poor adoption). There are 2 factors that normally limit AM audio quality Bandwidth and noise. Bandwidth comes down to transmitter and reciever design and use. Prior to the 70's AM was the major music medium and there were AM stations with better fidelity and bandwidth than FM stations...An example of this is WLW which after the FCC told them you "can no longer transmit at 500KW as the world's strongest AM station" decided "if we can't be the strongest then we'll be the highest fidelity"...HH Scott certified their AM station as having better fidelity than most FM stations at the time. Most stations and radios used on AM today are expected to be used for talk radio which prompts many stations and receivers to limit bandwith and fidelity to land-line phone like lousiness for cost savings. FM has the advantage of being mostly immune to RF noise. Most RF noise is more of a varying amplitude impulse than a varying frequency so FM recievers are basically designed to ignore it (called capture ratio)...FM recievers also tend to ignore whichever station has a weaker signal...So unlike the AM band the FM band will have closer spaced stations that effectively interfere with eachothers geographical outer fringe coverage...Case in point ever listen to FM on a long road trip and after a moment of noise (say while cresting a hill) suddenly your hearing a different station despite not changing the frequency?...That's capture ratio in action.
In the last 20-30 years switchmode power supplies have become more prevalent (in every device you plug in) and those tend to be basically huge RF noise polluters and tend to disproportionately affect AM because of AMs lower frequency. A switchmode supply usually creates (and doesn't bother to contain) a 17KHz square wave...And if enough of my college electrical engineering Fourier analysis class is still with me, a square wave consists of a STRONG sine wave at its fundamental frequency (in this case 17KHz) and an infinite series of harmonic (read that multiples fo the fundamental) frequencies above that (for example 34KHz, 51KHz, 68KHz, etc all the way up to infinity Hz ) and as the harmonic frequency decreases its intensity decreases so a 17KHz CFLor phone charger, or computer power supply, etc will generate louder RF noise in the AM and frequencies than at the FM band frequencies.
A final mind blower to some people: AM and FM are just interchangeable techniques to place audio on an RF carrier...So you could modulate an RF signal in the AM band with FM modulation or an RF carrier in the FM band with AM modulation....In fact in the Ham radio world, there are frequencies that are/have been used interchangeably with AM or FM modulation.
Came here for this comment alone. AM sound quality is the victim of its modulation and current bandwidth.
Nothing changes the fact that AM BW is limited by the FCC at 5kHz max while FM is 15 kHz, noise be damned. AM will never surpass FM fidelity.
Maybe *at the time* WLW was better but not now.
WABC 770 AM in NYC was always on my sister’s car radio when I was a kid growing up in the early 70’s in Connecticut. After we’d moved to Pittsburgh in 1981 I put a TV antenna atop the back porch of our house and connected it to my AM/FM stereo receiver. I did it to get better local FM but I was stoked to discover that at night I could pick up WABC in NYC. I thought it was the coolest thing to get that familiar signal from 400 miles away.
WABC operates a single tower omnidirectional station at 50kW from Lodi, NJ--about a mile away from Tony Soprano's "Badda Bing" strip club filming location (Satin Dolls, in Lodi).
@@W2IRT Bada Bing
I like to listen to WSM in Nashville, though I live in Louisiana.
I've spent many warm summer nights on my back patio with just a radio and a bottle of beer, listening to the music while staring up at the stars.
More recently I've been having fun tuning into distant shortwave stations.
I sometimes to listen to WABC 770 through a old AM radio i have, I live in Fort Wayne, Indiana
There's a station based in denver that runs on 850khz (850KOA) that is nicknamed the "blowtorch of the rockies". It is so ludicrously powerful to get through all our mountains that it can be picked up in Siberia.
As this video just explained, AM signals bounce off the ionosphere at night, and carry for great distances. The Rocky Mountains have no impact on a 50kW AM signal like KOA.
The mountains DO have a huge effect on Denver’s FM stations however, since their signal waves do not bounce.
As a kid in Minnesota in the 1980s I discovered that at night I could regularly tune in KOA from Denver and WLS from Chicago, and occasionally I even picked up WOR from New York, and over the years I learned about 'clear channel' (lowercase) stations, but I don't think I really understood *why* they were stronger at night until I watched this video today.
I miss WLS 89khz before it became talk radio in the late 1980s.
FYI - There’s a mistake in the narration starting at 01:44. After he shows the green lines going upward and correctly says “the FM waves go right through (the ionosphere”), the RED lines that appear represent an AM signal but the narrator inadvertently refers to it as an FM signal. Indeed it is an AM signal which, at night when the lower level ionosphere dissipates, the AM signal bounces off the upper level ionosphere and can travel a much longer distance.
Fun fact: You can also sometimes hear meteors enter the atmosphere at night on AM radio
I’ve always wanted to start a radio station that plays Video Game music unfortunately I learned about copyright later in life and my dream may never become a reality. :/
I don't know how it's like where you are, but where I am radio stations simply pay a fee to an organization and can then play whatever they want. That organization then distributes money to the copyright owners according to how much their stuff has been played. So what I'm saying is it might be easier than you think.
Start A unlicensed radio station on Shortwave or LW or on AM (MW)
you get an ascap/bmi license like every other radio station bro
This is INCREDIBLY fascinating!! Thank you for putting so much work into these videos - we all appreciate it!
8 people are flat earthers
I don't normally reply to these kinds of things, but it's 319 now.
@Andy Madden Now 366
Close but no cigar. The ionosphere does play a major part in this, however it's the lowest layer, called the D-Layer, that makes it possible. Or rather the *absence* of the D-Layer. At sunrise the D-layer forms and lower frequencies are absorbed by it, so the station remains ground-wave only and covers the local listening area. At night the D-Layer disappears and the signals can get to the higher layers of the ionosphere where they bounce back to Earth. Also, most AM broadcast stations operate directional arrays changing pattern at daybreak and twilight.
Here in Brazil, a former radio station used 10 kW at day and 1 kW at night, with their transmissions reaching almost the same distance (slightly better at night, of course). The transmitter operator always received a letter from a government agency with a schedule indicating the precise time to change the transmitters along the year to avoid conflict with another stations from the region.
Back in the 60s, in my teens, I had a hobby of tuning for, and catching am radio stations at night. There used to be a LOT more of the "clear channel" stations than there are today. A few years ago the FCC removed a bunch of the 50,000 watt clear channel stations from being "clear channel". If you sent a letter/postcard to most of these stations, reporting what you heard and the time, they'd send you a return postcard, known as a QSL card, proving you heard that station. I had quite a collection of these cards, with the farthest away station I received being KDKA in Pittsburg PA, with me being in San Diego CA. That station was somewhat of a hard one to get as there was another station on the same frequency in Los Angeles. What it took to catch KDKA was, the LA station would go off the air late sunday night-early monday am for maintainance and one early monday morning I caught KDKA. KDKA is better known as the first actual commercial radio station in the US, on Nov 2, 1920.
I'm pretty sure that the channel in Chicago is not "KMVP", since that call sign is for a station in Arizona (that recently switched from AM to FM. Also, radio stations broadcasting from East of the Mississippi all begin with the letter "W" (For the most part, there are a few exceptions like for instance in cities that straddle the river like the Twin Cities in Minnesota, which use "K" even if the tower is on the East side of the river, like for instance KSTP in St Paul, which I used to live across the street from)
WMVP is a broadcast radio station in Chicago, Illinois, United States, providing Sports News, Talk and Live coverage of sports events as the flagship station of the Chicago Bulls.ESPN Network.
820 WBAP (Dallas) and 1200 WOAI (San Antonio) are some other exceptions to that west of the Mississippi rule.
Some nights, you used to be able to hear an AM station from Boston all the way down in Florida on a walkman.
yup
As I am old (40+), I remember playing with my radio and the antenna some nights as kid, trying to pick up radio stations from as far away as possible.
Past AM, you move into SW, MW and LW (short, medium and long wave) territory... but thats another story for another time or for a doomsday scenario.
....and Short Wave is the most interesting of the three. Maybe worth doing a video on as a follow up to this one?
In the UK (and I'm guessing most of Europe) it's MW, FM and DAB (Digital Radio) now. No AM.
Get over yourself mate
InsaneGamers, I can sometimes pick up a German AM radiostation. The last Russian am radiostation was shut down 3 years ago, a shame, really, now geologists, meteorologists, hunters and etc. have nothing to listen too.
I've heard that some of the BBC World Service channels have very long wavelengths that you can listen to it from the other side of the globe
2:36 Wrong. The AM band starts at 530 kHz, but that frequency and 1610 kHz is only used for traveler information stations.
3:16 WMVP not KMVP. Chicago is located east of the Mississippi River. Stations east of the river have callsigns that begin with W, whereas stations west of the river have callsigns that begin with K.
2:20 this is completely true, I work for a AM station in Boston and someone got our signal in Norway and sent us a audio recording a couple months ago.
@roger darthwell Yes, guy said that he was in the Telemark region.
I learned about this from Lost. Sayid tells Hurley that the sound they’re hearing from the radio is from really far away and bouncing off the ionosphere.
Excellent video as always, but I noticed a little mistake. There is no station called KMVP in Chicago, but there is a station called WMVP. Generally in the US, stations west of the Mississippi have a call sign starting with K (although there are some exceptions like WFAA in Dallas) and stations east of the Mississippi have a call sign starting with W (there might be some exceptions, but I'm not sure).
I am a native of the Chicago area and never knew AM 1000 had the WMVP call sign! I only remember it as WCFL back in the day when it was a rock station! LoL.
Try KDKA in Pittsburg...
What isn't mentioned is, just like propagation (or skip) with CB and HAM operators, people outside the line of sight but not along the outer edge of that circle may not even know that station exists because the signal passes right above them while bouncing.
30-40 mile range for FM?
I've picked up FM radio in my car from 60-70 miles away from the tower.
Apparently 103.5 BOB-FM Austin has a big antenna (like 1200 ft) and the place I got it from that far away is around 150 ft lower in elevation
Truth is, it depends. HAI generalized a lot so his vids could be more on topic. The average station usually makes it 80-90 mi if one is willing to put up with some static. If you go up on a local hill or mountain, the range now becomes 120 mi. It's all about line of sight. Also, Tropo can increase this range even further.
I love how we can see your style evolve in your videos. Your currently ones are way more animated
Personally I'm finding that I like the calmer and quieter sam. Much easier to take in all the information
You don't need to be an skilled operator. Just buy a shortwave radio and you can listen to radios from literally all around the world
Huh. This explains a weird thing that happened when I was a kid.
My grandparents live ~12 hours away from me and I spent many hours in the back seat of a car riding to and from their house. One time as we were returning from their house, we were flipping channels on the radio and were able to tune in to their local talk radio station some 600+ miles away.
I'm a little concerned that I knew 100% of the technical stuff in this video.
Go brewers
I sleep everyday listening to your podcast... when are going to upload a new episode? I really enjoy listening it at night. Greetings mate.
Oh shit I might actually have to learn something.
αηδγ ςλαη Greek?
I guess this explains why my PC speakers start picking up French radio after the sun sets!
I presume this is why one of the largest companies that own an operate radio stations is called "Clear Channel Communications". Even though most of their stations are FM, naming the company after the most powerful and highest status AM stations is definitely a power move.
Informational but super simplified. AM and FM are only modes and have very little to do with propagation. As for the FM sounding better because of the higher frequency, that in itself real doesn't have much to do with it. It has to do with the mode. Wide FM takes up over 100kHz of bandwidth, while an AM station is only 1/10th that. As far as the distance AM signals travel during the day, there is also a lower layer of the ionosphere that absorbs RF energy with wavelengths generally below 10Mhz during the day, but is one of the first layers to dissipate around sunset. Its all a lot more complicated than a short 5 minute video can address, but it gives the general gist of it.
Because there are not enough TOYOTA COROLLA.
Wrong channel xD
Here, we need him to talk about PLANES
Also, where was the cartoon cow?
This is Half as Interesting, not RealLifeLore.
This shows that most of the subscribers of the two channels are shared :) mee too, great videos
The Earth wrong channel m8
Here in Philippines you can pick am stations from far away place at night but not in a day
“you might have to learn something this episode” *clicks off*
That's why people still go to American school, because school doesn't teach anything! It actually doesn't teach effectively or the right information.
I just tried tuning in to AM radio in Barcelona at night and I was able to listen to a few radio stations in Arabic.... I'm guessing from Morocco.
I don't know if this is a normal occurrence, but I was able to pick up WJR 760 AM out of Detroit all the way from Rochester, NY, through Western Pennsylvania and the entirety of Ohio, all the way to Indianapolis, IN, during a drive during daylight hours. Of course if you look at a map during that journey you are never super far from Detroit, but still that is pretty impressive.
Yep, if this was in the winter, stations come in well before sunset, since that "D" layer doesn't build as much. Same thing in reverse after sunrise. I had a couple of 600 mile stations close to noon locally.
Even here in New Jersey,too!
When I was a kid, a friend gave me a large console tube radio from the 30's. I was able to get it working and found new tubes for it, built a high gain antennaand started listening. I was able to get Radio MOSCOW from Long Island.
Supposedly curves.... Doesn't want to lose views from flat earthers
Those sweet sweet views
@@eelsemaj99 they're attractive 😂
Um, that was an extremely confused explanation of radio wave propagation. AM and FM are techiques to modulate ("add sound to") a radio signal. It doesn't matter if the freequency is 1000 kHz or 100 MHz, you can modulate both with AM or FM. If you [break the rules and] modulate a 1000 kHz transmitter with an FM signal, then you would experience exactly the same radio wave propagation as you do with the usual AM broadcasts on the same frequency. It will be the same thing at 100 MHz; where the signal propagation won't change because you switch between AM and FM.
What does matter for the radio wave propagation is the frequency (or the wavelength if you prefer using that) and how it interacts with the atmosphere, mainly the ionosphere, and how that, in turn, is affected by radiation from the sun.
Half Toyota Corolla references and Half Plane references
FM radio isn’t only line of sight. That is an old wives tale. I’m originally from Hartford, Connecticut and can remember back in high school I used to routinely pick up FM stations from New York City and Boston, Massachusetts which are both just over a hundred miles in either direction from Hartford. My favorite stations were KISS 108 (WXKS 107.9) in Boston and the now defunct KISS FM (WRKS 98.7) in New York City. I could also pick up WBLS 107.5 in New York City. When my brother went away to college. He went to Purdue University, which is in West Lafayette, Indiana. That is about a hundred miles outside of Chicago. He used to pick up the now defunct WBMX 102.7 as well as WGCI 107.5 on the regular on his boom box and record their house music mixes on cassette and bring them home.
I thought I was the only one with this experience. I remember back in Winnipeg MB we could pickup FM stations from as far away as Fargo ND which was about 220mi away.
I live in the Philippines and when I turn on the AM radio at night occasionally, I hear chinese radio stations hahaha
Wehh meron nga ano oras??😂
RCI perhaps?
seyymmmm. Taga Mindanao pa ako ahahahah
*Farther
Further is only used for non-literal descriptions. "Getting a good education can help further your career."
Farther is used when you are talking about physical distance.
Very interesting... but how does this affect planes?
Lotsa bunny trails. Info you might not encounter otherwise.
Living in Chicago, I have to make a correction to this video. At 1000 am, the radio station is actually WMVP, which is ESPN. KMVP is actually Arizona sports radio. Just letting you know!
Because it's pm!
lmfao
well phase modulation is a thing
hhahaha...no.
Only half of the night is in PM, the rest is in AM. And half of the daytime is in PM, anyways. AM and PM don't have to do with day and night.
It's WMVP in Chicago, not Kmvp....
So what happened to radio stations during the solar eclipse?
For a few minutes, night time reception prevailed; but remember, it's day or night in the AREA OF THE BOUNCE that counts; so radio stations and listeners AT EQUAL DISTANCES AND OPPOSITE HEADINGS FROM THE CONE OF TOTALITY are briefly connected, NOT stations or listeners IN the cone of totality.
Allan Richardson I am confused with you trying to highlight too many of your words with capitalization. The previous comment didn't specify anything, OP just wanted to know what happens to radio stations during a solar eclipse.
MischievousMoo Sorry I can’t use italics or bold or underlining in this app.
After rethinking the matter, it may not be worth computing the effect of an eclipse on radio wave reflection, since the darkness is so short. The transition from night to day and day to night are slow and gradual, giving time for ions to form or neutralize. An eclipse takes much less time. If anyone has actually had a radio contact during an eclipse on a frequency and over a distance that would normally only be possible at night, they can post their experience or a reference to any data that may have been published.
In any event, the eclipse would have to be passing a point halfway between the two stations, not the location of either station. Meteor scatter works the same way, but that’s another story.
This is very important for people who work out in the open ocean, as one the ways of sending a distress/safety message is using HF equipment (basically AM). We work out a distance to a coast station, from that we know the frequency to use. For 500NM it’s 8kHz, but if it’s night it’s 4kHz. So it’s important to always remember this, as the last thing you want is for your mayday to bounce miles away from station you wanted to get in contact with.
and thats why the world is switching to DAB+, also can you do a vid on the naming of us radiostations? the names seem a bit wheird to me as a european.
Kars Noordhuis most of the characters mean nothing, but the first letter will tell you location. The division here is the Mississippi River. To the west, you’ll find stations that start with K (KOMO KTAR KIIS KJZZ KSLX), and to the East you’ll find W and Z (Z100 WPLK WVLM).
K
Ah, you live west of the Mississippi River?
Kars Noordhuis Some of the non-callsign names foreign stations have seem weird to we Americans, like, for example “Super Happy Fun FM!”
Mystery Man Z100 is a name for WHTZ, among others (there is/was also a Z100 in Portland, Oregon). Z is primarily assigned to the UK & Brazil by the ITU.
From an radio frequency engineer's point of view I think your video here is pretty good, however there is one issue I have with it. You can be left with the impression that AM radio signals go further because of the mode of transmission, this is not the case. The propagation of the radio signal is purely based on frequency (and consequently it's wavelength) and not the mode of operation. In theory there is nothing (except licencing) to stop you transmitting an FM signal on 1000kHz (or 1MHz as I would prefer to say), and this would travel as far as an AM signal would do. And the opposite is true too, there is nothing stopping you transmitting an AM signal at 100MHz. In fact this (almost) happens as the aircraft band 108-137MHz uses AM as it's mode of transmission.
But overall you have a good video that the general public will understand and enjoy :)
Wait
"Since the Earth is supposedly curved,"
Wendover is a Flat Earther confirmed?
No, it’s a joke at the expense of flat Earthers.
True.
You've left out a LOT of important details!
KOMO and WMVP (not KMVP) are both directional Class A, but they both use directional antenna arrays at night (KOMO actually provides a signal with more than 50,000 effective watts, but almost no signal to the West, WMVP (not KMVP) sends it's power eastward, in fact, WMVP actually bought billboards in Detroit to advertise Bulls basketball when the Bulls dominated the NBA. They send almost no signal westward at night.
The coverage of seemingly similar AM stations can vary drastically. A 5,000 watt station in North Dakota, near the bottom of the band, can carry through ND, SD and a lot of Saskatchewan, whilst a 5,000 watt station in Georgia at the top of the band may only go out to 15 miles.
Most of the regional channels were given out on a "first come, first served" basis, the first station on the channel will have good coverage, every other station on said channel tolerates the first station's interference, and has to build an expensive directional array so it doesn't affect the "senior" station.
You'll know an AM station is directional by seeing more than one tower (as many as twelve!) at its site.
Also, there are six "local" channels (1230, 1240, 1340, 1400, 1450 and 1490) where Class C "local" stations are 1,000 watts all day and night. By day, these stations go out as far as the soil under the station can carry the daytime signal. If you look up the FCC's "M3 soil conductivity map", you'll get to know which local stations have good or bad daytime coverage (at night, all of these stations interfere with each other, leaving only their small town with a good signal)
For what it's worth, there are cases where FM stations can be heard FAR beyond the line-of-sight.
Often, an "air inversion" can "trap" an FM signal into following the curve of the earth (most often observed late at night or early morning). This is particularly true over lakes and oceans.
Sporadic-E skip will sometimes reach the FM broadcast band. It is not as common as it is on the 6m amateur band or TV Channels 2-6, but it is a true ionospheric skip mode, allowing FM reception from stations about 1,000 miles (1,600km) away, and not the stations between your site and 700 miles.
Look for it late May through early August, in late mornings and around sunset.
If the circumference of Earth was 25,000 miles, it would calculate to a curvature of .75 x #miles squared; which means that for a FM radio signal to reach 35 miles the transmitter tower would have to be over 900 feet tall, as tall as the Empire State building in NYC. DO YOU SEE ANY RADIO TRANSMISSION TOWERS AS TALL AS THE Empire State BUILDING?
The Empire State Building is already a radio tower. Most transmitters are placed on tall buildings in the city in the US, so they don't have to make the tower so tall.
Also: The empire state building is 381 metres tall. Bilsdale transmitting station in the UK is 314 metres tall. Emley Moor is 330 metres tall. So yes, I have seen them get that big.
I should have been more specific; do you see 900 foot tall radio antennas every 35 miles?
900 FT? No the Empire State Building is 1200 FT high, and that's not including the antenna on top which gives the overall building a height of 1400 FT.
OK, smart guy, how about this: for the Earth to have a spherical circumference of 25,000 miles, and curvature of .75 x miles squared this would calculate to .75 x 50 x 50, or 2500 x .75, which is 1875 feet of curvature over 50 miles. The new 'freedom' tower in NYC is 1776 feet tall, so for radio transmission signals to cover America, it would require one tower every 50 miles as tall as the 'freedom' tower. Now, DO YOU SEE A RADIO TRANSMISSION TOWER AT LEAST 1875 FEET TALL EVERY 50 MILES? YES, OR NO?
InsaneGamers, there is a 628 meters tall mast in the us and there was even taller one in Poland.
"Much like a stab wound"
LOL, this channel is one of the best I have ever seen. You make the boring stuff from a textbook seem WAY more interesting. You have a great talent, and I love your dry sense of humor. Keep up the good work.
I think you mean WMVP not KMVP
Why doesn't a single buyer just buy up all the channels on a given frequency? That way during the day they can customize programming to the area and at night they can just broadcast some common programming everywhere?
I get that there are clear channel broadcasters but I'd imagine there would be some synergies here that a single owner could exploit.
Yess!!! Finalyy smaller is better
Manas Sharma Chinese and Indians must be overjoyed 🤣
manhoosnick Chinese people*
That's a racist joke.
When you mentioned KMVP in Chicago, didn't you mean WMVP? Because Chicago is east of the Mississippi River, and all call signs east of the river begins with W. I bring this up because I live in Phoenix, Arizona, and we have a radio station with the callsign KMVP.
because if they did work they would be called PM's
That ad transition targeted me directly. I'm in the process of starting a radiostation😂
at 1:44 you say 'FM' but you mean AM
Nope. He meant 'FM'. Listen to the two sentences before that one. Basically, AM can bounce off the ionosphere, so it doesn't need direct line of sight. But "without the bounce" (because it doesn't bounce off the ionosphere), FM can only cover in line of sight (ignoring things like most buildings and trees, since FM can generally penetrate those, but not the earth itself).
In the old days those were called "Daytimers". They had to go off the air at sundown to avoid interfering with stronger stations in larger cities. Daytimers were only in small towns. KNGS 620 in Hanford, CA had to go off the air at night to avoid interfering with KFRC 610 in San Francisco, 150 miles away.
I had no idea AM radio was still a thing? I don't think I've heard any AM radio for decades. In my country FM radio is also dying out, we're switching to digital radio (DAB+)
DAB is not really that good. Expensive and not much better than FM
There are some stations in Europe.
PapaQ AYYYYYYYYYY DAB ON EM
The US NAB is primarily why we don’t have a separate DAB band here. We’re stuck with “HD Radio” by iBiquity which is horrible.
If you are doing 'science talk' don't equate broadcast mode with frequency band. I know that's how the bands have long been referred to in the US, and we in the UK eventually adopted it because of imported japanese radios, but it's wrong!
What was meant by "the earth curves, supposedly", flat earther on this channel?
joke at the expense of flat earthers
If you want to hear what it would be like if every station transmitted full power around the clock, tune in to a “graveyard” frequency at night: 1230, 1240, 1340, 1400, 1450, 1490 kHz!
So very true. Sometimes you get lucky and something pops out, but yep, jumbled speech on those frequencies (unless they're local)
I screen shotted this comment I’ll try those frequencies tonight. I’d imagine it sounds like you’re sitting in a full restaurant people talking all at once glad FM don’t have this problem
@@kevindavis4709 thanks to the capture effect, and that VHF waves mostly pass through the ionosphere! But, every now & then you get tropospheric ducting on VHF, and that’s fun!
America still uses AM?
Maybe for the sparsely populated areas it's better with its range, but FM has better quality, no?
I think FM is way more expensive, and as said, doesn't reach as far.
Given the population density in rural America, low-bandwidth & high-distance channels like news, sports, traffic are good to have in AM radio. for music and local stuff you would use FM stations. Also, thousands of AM stations in such a large landmass is not very significant.
Typically speaking, AM radio tends to be talk radio while FM is music.
You people still use FM? We use DAB (yes it's a thing, and it's better than both FM and AM)
im using DAB
I live in Phoenix, and I can pick up AM stations from as far west as Los Angeles and San Francisco, as far north as Denver, and as far east as Dallas-Ft. Worth.
Cool
Nice
Neat
You deserve a million subs for both channels because of your exact quality of each vids
@0:03 I already know how to think so I don't need brilliant. Brilliant! 😋 (worst pun ever)
The subtle humor is hilarious. Well done.