# Radio transmission range

**URL:** <https://boards.straightdope.com/t/radio-transmission-range/28448>\
**Category:** Factual Questions\
**Created:** [August 7, 2000, 6:20pm UTC](https://boards.straightdope.com/t/radio-transmission-range/28448 "2000-08-07T18:20:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![castle\_bravo](https://avatars.discourse-cdn.com/v4/letter/c/7ab992/32.png) [@castle\_bravo](https://boards.straightdope.com/u/castle_bravo)\
**Post date:** [August 7, 2000, 6:20pm UTC](https://boards.straightdope.com/t/radio-transmission-range/28448/1 "2000-08-07T18:20:09Z")

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What is the approximate range (distance) per kilowatt of power of an FM radio transmitter? I have searched the net and there aren’t many beginners guides to high power radio transmitting.

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**Author:** ![LIONsob](https://avatars.discourse-cdn.com/v4/letter/l/76d3ee/32.png) [@LIONsob](https://boards.straightdope.com/u/LIONsob)\
**Post date:** [August 7, 2000, 6:46pm UTC](https://boards.straightdope.com/t/radio-transmission-range/28448/2 "2000-08-07T18:46:53Z")

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The output power of the station has little to do with the distance that it can be received.  
At the frequences that broadcast FM operates (VHF) the height of the transmit and recieve antennas and the curvature of the earth control how far away from the station that you can receive it.  
On a normal day that range is about 50 to 120 miles depending on how high your recieve antenna is and how sensitive your reciever is.

Peace  
LIONsob aka KC5LNN \<-My Amateur Radio Operator Callsign Issued By The FCC

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**Author:** ![whitetho](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whitetho/32/1059_2.png) [@whitetho](https://boards.straightdope.com/u/whitetho)\
**Post date:** [August 7, 2000, 7:10pm UTC](https://boards.straightdope.com/t/radio-transmission-range/28448/3 "2000-08-07T19:10:12Z")

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There is a comprehensive review at: [Prediction of FM Coverage using FCC Charts](http://www.rapidnet.com/~tepco/fccpred.htm)

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**Author:** ![KCB615](https://avatars.discourse-cdn.com/v4/letter/k/ea666f/32.png) [@KCB615](https://boards.straightdope.com/u/KCB615)\
**Post date:** [August 7, 2000, 8:12pm UTC](https://boards.straightdope.com/t/radio-transmission-range/28448/4 "2000-08-07T20:12:04Z")

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Our radio transmits at 100 watts, and its odd how far the signal can travel. At the opposite side of town (5 miles to the west, slightly downhill), one can’t hear the signal. Go 25 miles north (somewhat uphill), and you can pick the signal up like you’re standing next to the tower.

I don’t profess to know how it works, I just know when it doesn’t work.