Mexican radio stations have call signs that begin with the letter X which is what ZZ Top was referring to when in that song “I heard it on the X”.
American stations east of the Mississippi start with W and west of the Mississippi start with K except for older stations that have grandfathered call signs like WOAI in San Antonio TX.
Broadcast AM station’s long range has everything to do with its low frequency and long wavelength and nothing to do with frequency modulation. Television stations use AM for the video and FM for the audio and they are just as line of sight as FM stations because of the short wavelength. In fact the entire FM broadcast band is right between TV channels 6 and 7.
There are two reasons for AM’s long range. First it is vertically polarized. The broadcast antenna’s are 1/4 wavelength with the other 1/4 wavelength reflected by the ground. This attaches the wave to the ground, so it tends to want to follow it.
The long wavelength extends from the ground to quite high in the air. The denser air at the ground causes the lower part of the wavefront to move slightly slower than the top part of the wavelength. The top move ever so slightly faster so it “tips over” at about the same rate the earth curves, so it will follow the curvature of the earth for long distances.
FM is horizontally polarized so the whole wavefront is at the same height above ground. A half wavelength antenna is needed because there is no ground reflection. The signal just travels in a straight line, but due to its relatively long wave length compared to say microwaves, there is more “scatter” so antennas that are not in the direct line of sight can also pick up a useful signal, just not at the distances of AM signal.
At night where the ground keeps air a little warmer that the air higher up, the tipping is increased so the signal can travel much further than during the day. The correct term of the tipping of the wave is refraction.
When I was 12 years old my 6 transistor AM radio sometimes had trouble receiving the local station 8 miles away during the day but could frequently receive Wolfman Jack over 1,000 miles away near Tijuana, Mexico loud and clear late at night.
This also happens with sound waves. In the late evenings, you get a thermal inversion where there is cold air near the ground and it gets warmer as you go up in altitude. The speed of sound is slower in cold air than hot air so the sound waves tend to “tip over” and stay near the ground.
This is why you can sometimes hear the marching band at a high school football game from five miles away, or fishermen talking to each other on a boat a mile offshore on a lake.
It’s called acoustic refraction. That layer of cool air on the ground does to sound waves what an optic fiber does to light beams. The sound is trapped in that cool blanket of air.
I get Michigan and Chicago on my little walkman in Minnesota at night. Not in the day though. Did you know that Michigan borders Minnesota? Yes it is so. North and South Dakota, Iowa, Wisconsin, and Michigan, not to mention Canada. You can’t drive there though because the border is in Lake Superior. You need a boat or an amphicar.
Can’t you just cut through Wisconsin to get to the Upper Peninsula?
You know, I have always wondered what it’s like to live where the state line isn’t an all day drive away.
Yes of course Wisconsin borders the UP. Getting tired though. Lake Superior, not Lake Michigan. Take the boat east a little from Minnesota and you’ll run into the border of Michigan. A few hundred miles though by boat to the UP if it’s land you want.
Where I live is a 20 min.from Alabama when I lived in south Fla it was an all day drive to get to the state line the only problem with me going io Alabama depend’s on what I am going for as Alabama is in the central time zone.
An hour was about how long it took me to cross Alabama when I drove from Austin to Tampa. Mississippi and Alabama went by real fast and then it took all day to reach Tampa from Pensacola.
I-10 through Louisiana was all concrete with expansion joints every hundred feet or so, ka-bump, ka-bump, ka-bump through that entire state. Once I flew to Tampa with a stopover in New Orleans and when that plane landed there and taxied to the terminal, ka-bump, ka-bump, ka-bump, I said, “did we land on I-10?”.
What is it with Florida’s exit numbers on I-10? Most places, the exit numbers correspond to the mile markers but in Florida, it’s exit 1, exit 2, etc regardless of the mile markers.
This isn’t a stop sign, but it’s a road sign, so I thought someone would get a kick out of it.
I took it on a secondary highway in North Dakota in 1971. I never did understand the reasoning behind it.
Texas used to have a 65 mph night time speed limit on its 70 mph speed limit highways but they did away with that a few years ago. Now it’s the same speed limit day or night.
I can’t figure out why the night speed limit would be higher unless it’s related to lower congestion, or maybe it originally had a higher daytime speed limit and when they lowered it, they forgot to take the night time speed limit sign down.
If you remember back in the old days, 50’s and 60’s, the day speed limit used to be 65 most places on two lane roads. But they all had a night limit of 55 that was blacked out during the day but could be seen at night with the headlights on. So probably the guy was told to put the new speed limit sign up but forgot to take the old one down. Who knows. Actually though the dual speed limits made a lot of sense.
I dunno though driving through Montana or South Dakota west to east is very long. Probably told it before but we left Mt. Ranier Friday night and I headed for Minnesota. Drove all Friday night. All Saturday and Saturday night. All Sunday and Monday morning I was still around Wall Drug with about 600 miles to go yet so I called work saying I wouldn’t be in. Yeah I did stop a few times for a few hours sleep at rest areas but still that was a wicked drive straight through.
There was no congestion anywhere in N.D. in that era. The area where the sign was is downright desolate… always.
Your second possibility makes sense. But I have no way of knowing if that was the actual reason. Or perhaps the town budget could only pay for changing one sign that year.
If anybody knows the real answer, I’d love to know… even 46 years later!
I forgot about that. I think the city of Austin has more people in it than North Dakota, South Dakota, and Wyoming combined. States where the senators outnumber the representatives to the US Congress.
At least in the plains, you want to slow down at night. Deer and antelope do indeed play out there, and they like to do it on the road.
I was driving from Aberdeen SD to MN one year late at night. Speed limit was 65, and that’s what I was doing. Suddenly I saw a semi about half a mile ahead of me swerve and slam on the brakes, then pull over and stop.
I slowed down, of course, but the dope in the Cavalier that had been barreling up on me did not. Passed me, accelerated, then ran over the absolutely giant buck the semi had hit. Thing was the size of a moose.
Looked like a scene out of Knight Rider. His car shot up in the air, then slammed down and threw sparks everywhere. Broke his suspension on all 4 corners, and I’m surprised he didn’t break himself.
I’m always leery driving out there at night since then.
I live in a suburban neighborhood and we have plenty of deer playing in our yards, along the roads, and even in the roads. I drive with my high beams on everywhere I can without blinding someone because of deer traffic. I go 20 to 25 in the neighborhood during the day because of children, but I do it after dark because of the deer.
