Outdoor FM Antenna

You stated Washington DC that is 10 miles square not having 6.3 million people. 20 mile radius of Washington DC is 3.7 million not 6.3 million, .I am not changing radio station antenna length as they are normally 1000 to 1500 feet. Home antennas are limited to 100 feet. You been posting bad info consistently. FM antenna height by FCC.

The average FM station antenna height is determined by the Height Above Average Terrain (HAAT), which is crucial for effective broadcasting.

• For Class C0 stations, the HAAT must be at least 300 meters (984 feet) above average terrain. 

  Class C stations require a HAAT of at least 451 meters (1480 feet). 

• The HAAT is calculated based on the average altitude in the area near the antenna site, which helps in determining the range of broadcast

• 
  These regulations are set by the FCC to prevent interference and provide optimal signal coverage.

Have a nice day. I have no idea what this was about or what you wanted from it. As to the population data, once again you put words in my mouth and then claim they were erroneous. I did not say anything about the square area of Washington DC proper. I did say that the census bureau says that the population of “the greater Washington area” was 6.2 million in 2023. And we are talking about a 22 mile radius (not area) at 330 feet. I trust you would agree that a broadcast antenna radiates signal in all directions typically. A circle with a 22 mile radius has an area of more than 1500 square miles. If you’ve ever been here you would know that DC is surrounded by densely populated towns in MD and VA, to account for most of the population of the greater DC area.

You stated Washington DC not greater area. My info is from the internet and city radius calculator that does not agree with your now greater radius population- not even close.. You are just wrong.

An FM station antenna power and height vary by region. Most of the East down to Southern VA and over to Missouri as well as much of California are in Region II, where maximum power and antenna height is 50 kw ERP @ 150 M (492'). Much of the Southeast, all of the Great Plains and Rocky Mountains and Pacific NW, max power is 100 kw at 600 M (1,968'). There are other classes of FM station that operate with lower powers and antenna heights - too many to go into here. Needless to say, a station with 100kw ERP at nearly 2,000 ft has a signal that will go much farther than one with 50 kw @ 492'. So, it all depends on where you live. If you want an estimation of FM coverage areas, check radio-locator.com, enter your market or the calls of a particular station and click on the yellow spot with the "i" in it for power and with an additional click, the typical coverage area. It will show whether the station is directional or not and give you city-grade, usable and fringe coverage contours. It's invaluable for FM listeners.

@realgoodsound 

First time I hear of radio-locator.com. It's an amazing resource, thanks for sharing.