Radio Station numbers and power?

Question

Does the radio station number reflect how powerful the signal may be? If not then what does? I have some stations that I can pick up for a long way and others that I lose quickly. Why is that? Does it matter that I live in Colorado very near and in the mountains? Star me!

Answer 1

I actually asked a question in this same vein earlier.

Typically, a station with a lower frequency (around the 540 kHz range), will travel farther than one with a higher frequency (AM stations have lower frequencies than FM ones), also the wattage of the station's transmitter may help things out too. Also, AM radio waves travel up the atmosphere and bounce back onto the ground at a long distance, keeping the signal strong, where FM signals go in a straight line, and are affected by obstructions such as buildings and mountains

Answer 2

I have read what others have written and some of them are fairly well informed.. I suspect that the did a search before they answered your question. I think most of them have missed something which is very important to your question. First of all there are no 100,000 watt stations.. some fm stations claim to have that much strenght but the truth is their maximum power is 50,000 watts.. fm stations actually have two signals.. one is horizontal and the other is verticle.. most a m stations have only one signal and it is horizontal.. fm stations who claim to have 100,000 watts.. use a polarized antenna.. it broadcasts 50,000 watts verticle and 50,000 watts horizontal.. combined it is 100,000 watts but each signal is only 50,000.. a horizontal signal pattern is flat.. (throw a pebble in to a pond and you will see the waves move away from the splash area in a horizontal pattern. Most a m stations have less wattage and must direct their signals to certain areas.. daytime and nighttime directions are different. That is why you may get on station in the morning but not in the evening.. Years ago.. the government allowed 16 am stations to be what is called clear channel stations.. in other words they were given patterns to follow and enough wattage to reach from coast to coast.. One of those stations is in Tulsa oklahoma.. KVOO.. it broadcasts its pattern in the immediate area and then south toward Lousiana and Texas and is strong enough to reach the souther tip of the country during the daytime, but it is required to follow the path of  the sun and at night it is directed towards California.. it is heard throughout the south west at night.. the stations were set up so that in case of a national emergency there could be complete coverage of the country.. As stations muliplied they were assigned less wattage and a more condenced service area.. because am stations have only a horizontal pattern.. the signal can be blocked by buildings and bridges.. fm stations with a dual signal pattern of verticle and horizontal ( verticle is an up and down signal pattern) this allows the signal to go aroung corners, buildings, under bridges and such.. some of the stations you cannot pick up all the time are probably directional am stations who must power down when the sun goes down.. some of the fm stations that you can pick up all the time, have more power and do not have to reduce power at night.. I know this was long, but you did ask a question that required it.

Answer 3

The other answers are fine and mostly accurate. (JWH could use a paragraph break or two). But there's one point I didn't see. And that is: in a manner of speaking, there is a correlation between the frequency and the power. I have simplified below:

You know about AM and FM. But radio stations are also separated by CLASS and CHANNEL. It's way too complicated to go into here, but suffice to say that it is easy to see why you perceive that certain frequencies are stronger than others. It's not your imagination.

Among FM stations, Class A's are the lowest commercial classification. Class A stations are limited in power (up to 6,000 watts) and tower height (about 300 ft). So their power is relatively low.

The highest-powered FM stations are Class C, or 100,000 watts and tower heights over a thousand feet. There are several classes and sub classes in between.

Power and tower height drive reception.

Certain frequencies are allocated to the classes. Therefore if you are listening to a station on 92.1 (anywhere in the country) it is a Class A station, and limited in its power.

I'm not going to list all the frequencies and their corresponding classes. At this point, anyone who is really interested can find all sorts of stuuf by going to their favorite search engine.

And yes it matters that you are in the mountains ;<)

-a guy named duh

Answer 4

Radio station numbers (i.e., their frequency) don't relate to how powerful the signal is.  The FCC licenses stations to transmit at different amounts of power and with different antenna patterns.  The power and pattern may be different for night and day since radio signals, especially AM signals, propagate differently during night and day.  You can go to www.fcc.gov, click on Mass Media Bureau, and look for AM Query and FM Query, then do searches for stations based on various criteria.  You can look up the stations' licenses to see what power and patterns they can use.

Above the AM band (e.g., for FM and TV), signals tend to propagate line-of-sight, so a mountain in the way will block the signal.  However, if you are high enough to look over surrounding elevations, radio signals should be able to travel over those surrounding elevations, too, so it depends on your height relative to the transmitter's height relative to the intervening terrain.

The AM band is low enough in frequency that the radio waves bounce off the ionosphere, so they can bounce right over the mountains.  That happens more at night than during the day, but reduced power and patterns tend to reduce the full effect of the increased nighttime propagation.

If you want to get better reception, you can put up an external antenna and/or add a preamplifier ("preamp") between the antenna and radio.

Answer 5

As the others said, those that are lower in frequency due to carry further than stations higher on the band on both AM and FM HOWEVER it's not a direct reflection on how powerful a signal may be.

Many factors come into play on that one... Basically how high is the tower (with the mountains being one of the best things for range), how much power is allowed by the FCC for that station (as some are only allowed say 5,000 watts, whereas others are allowed 100,000 watts depending upon where you live) and direction of the antenna (Am mostly as most FMs try to cover in a circle but not always)

So this is why say a station at 107.5 can be heard farther sometimes than say a station at 92.1 for... it all depends upon those three factors mentioned above.

A great idea of how far stations can go is the website http://www.radio-locator.com which gives all the details on the stations including power, height and clicking on a link..how far they will go.

For example, a station in Colorado Springs that can be heard perfectly in Denver, yet it's broadcasting from 70 miles away

http://www.radio-locator.com/cgi-bin/inf...

http://www.radio-locator.com/cgi-bin/pat...