# USA Centric: Radio Station Prefix **URL:** \ **Category:** Factual Questions\ **Created:** [April 19, 2015, 10:24pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071 "2015-04-19T22:24:48Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [April 19, 2015, 10:24pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/1 "2015-04-19T22:24:48Z")
My search-fu is failing, possibly from an exhausting day at work so here goes: Back before most of us were born radio stations here in the USA were finally designated with prefixes W for east of the Mississippi River and K for those west of it with a few notable exceptions. I realize the X prefix was used also. Now for my question. Why “W” and why “K”? Was this a Morse Code kinda thing? .-- for W and -.- for K? Idle minds want to know. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 19, 2015, 10:38pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/2 "2015-04-19T22:38:11Z")
this was arrived at by international treaty. the USA got to use call signs starting with AA to AL, K, N and W for radio. only W and K are used for broadcast radio. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [April 19, 2015, 10:41pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/3 "2015-04-19T22:41:15Z")
The Master Speaks (prodded, if memory serves, by SD poster **WhiteTho** ): > **[Why do U.S. radio call letters start with W in the east and K in the west...](https://www.straightdope.com/21343450/why-do-u-s-radio-call-letters-start-with-w-in-the-east-and-k-in-the-west-revisited)** ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 19, 2015, 10:45pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/4 "2015-04-19T22:45:09Z")
X was never a USA call sign letter. in North America XA–XI Mexico XJ–XO Canada , their broadcast calls start with C. ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [April 19, 2015, 10:56pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/5 "2015-04-19T22:56:04Z")
> [@Northern\_Piper](#): > > The Master Speaks (prodded, if memory serves, by SD poster **WhiteTho** ): > > [Why do U.S. radio call letters start with W in the east and K in the west (revisited)? - The Straight Dope](http://www.straightdope.com/columns/read/2303/why-do-u-s-radio-call-letters-start-with-w-in-the-east-and-k-in-the-west-revisited) Thanks. Still unanswered is why W is east, and K is west. Probably best commented by Cecil about civil servants and bureaucracy: “ **What happened is not known, but one suspects a memo stating in essence, all right, you morons, enough is enough.** ” ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [April 19, 2015, 10:58pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/6 "2015-04-19T22:58:39Z")
> [@johnpost](#): > > X was never a USA call sign letter. > > in North America > > XA–XI Mexico > XJ–XO Canada , their broadcast calls start with C. Yes I knew Mexico had call prefixes with X. I thought that originally X meant experimental. ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [April 19, 2015, 11:02pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/7 "2015-04-19T23:02:56Z")
> [@johnpost](#): > > this was arrived at by international treaty. > > the USA got to use call signs starting with AA to AL, K, N and W for radio. only W and K are used for broadcast radio. So call letters AA-AL are used for what here? And are they assigned specific frequencies? The FCC website is confusing and my brain is tired. 😃 PS You guys are great! ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [April 19, 2015, 11:11pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/8 "2015-04-19T23:11:56Z")
> [@Cabin\_Fever](#): > > So call letters AA-AL are used for what here? And are they assigned specific frequencies? The FCC website is confusing and my brain is tired. 😃 > > PS You guys are great! Well, one example I know of would be ham radio operator hobbyists. When I was a young child in the late 1950s-early-1960’s, my big brother was one. He was K6OAF. One could (and he did) even get automobile license plates with your call sign back then, long before “personalized license plates” were otherwise a thing. ETA: Okay, that began with K, not A. Still, it’s an example of radio usage other than the usual broadcast station stuff. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 19, 2015, 11:13pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/9 "2015-04-19T23:13:02Z")
> [@Cabin\_Fever](#): > > So call letters AA-AL are used for what here? And are they assigned specific frequencies? The FCC website is confusing and my brain is tired. 😃 > > PS You guys are great! radio services like ham radio, business radio and telemetry (remote data and control) all get call signs. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [April 19, 2015, 11:13pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/10 "2015-04-19T23:13:39Z")
The AA and other A series are used by hams, possibly other services as well. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 19, 2015, 11:18pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/11 "2015-04-19T23:18:11Z")
> [@Cabin\_Fever](#): > > Yes I knew Mexico had call prefixes with X. I thought that originally X meant experimental. X was often in the call sign of early experimental stations but not the first letter. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 19, 2015, 11:25pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/12 "2015-04-19T23:25:46Z")
> [@Cabin\_Fever](#): > > So call letters AA-AL are used for what here? And are they assigned specific frequencies? The FCC website is confusing and my brain is tired. 😃 > > PS You guys are great! most radio licenses are assigned a specific frequency(s). in ham radio you are allowed to use any frequency in a range of frequencies (band) based on your level of license (higher qualification license allows more frequency range). ---
**Author:** ![Rick\_Kitchen](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rick_kitchen/32/522_2.png) [@Rick\_Kitchen](https://boards.straightdope.com/u/Rick_Kitchen)\ **Post date:** [April 19, 2015, 11:27pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/13 "2015-04-19T23:27:04Z")
Although K in general is west of the Mississippi and W is east of the Mississippi, there are exceptions. KDKA is in Pittsburgh, and claims to be the first commercial radio station in the US. And WHO is in Des Moines. ---
**Author:** ![Cabin\_Fever\_1](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cabin_fever_1/32/2908_2.png) [@Cabin\_Fever\_1](https://boards.straightdope.com/u/Cabin_Fever_1)\ **Post date:** [April 19, 2015, 11:31pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/14 "2015-04-19T23:31:31Z")
> [@johnpost](#): > > radio services like ham radio, business radio and telemetry (remote data and control) all get call signs. Got that and understand. Just wondering where the W and K came from. OK - International treaty. Would have loved to see it: “What do mean W? We want a K also!” “We want a X! And a couple of XX’s while we are at it!” “Yah. C belongs to us.” “No. Marconi invented this. All alphabet belongs to us.” ---
**Author:** ![alphaboi867](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alphaboi867/32/3898_2.png) [@alphaboi867](https://boards.straightdope.com/u/alphaboi867)\ **Post date:** [April 20, 2015, 12:25am UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/15 "2015-04-20T00:25:15Z")
> [@johnpost](#): > > …XJ–XO Canada , their broadcast calls start with C. Some radio stations in Newfoundland & Labrador still use the **VO** prefix Newfoundland was assigned back when it was an independent dominion. ---
**Author:** ![Mr\_Downtown](https://avatars.discourse-cdn.com/v4/letter/m/8e8cbc/32.png) [@Mr\_Downtown](https://boards.straightdope.com/u/Mr_Downtown)\ **Post date:** [April 20, 2015, 4:43am UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/16 "2015-04-20T04:43:02Z")
I always speculated that W and K were particularly well-fitted to give to an English-speaking country, given the curiosity of those letters in Romance languages. [All you’d want to know about the K/W dividing line.](http://www.oldradio.com/archives/general/kwtrivia.htm) ---
**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:** [April 20, 2015, 9:43am UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/17 "2015-04-20T09:43:03Z")
> [@Mr\_Downtown](#): > > I always speculated that W and K were particularly well-fitted to give to an English-speaking country, given the curiosity of those letters in Romance languages. > > [All you’d want to know about the K/W dividing line.](http://www.oldradio.com/archives/general/kwtrivia.htm) That is a copy from ten years ago, and I update the page on my site annually, so if you are interested in what has changed in the last 10 years (ans: not much) then here is a link to the January 1, 2015 edition: [K/W Call Letters in the United States](http://earlyradiohistory.us/kwtrivia.htm). And to recap what the others have said, the assignment of K and W seems to have been completely random, with no significance behind their selection. ---
**Author:** ![JohnGalt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johngalt/32/184_2.png) [@JohnGalt](https://boards.straightdope.com/u/JohnGalt)\ **Post date:** [April 20, 2015, 5:24pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/18 "2015-04-20T17:24:41Z")
Someone told me a long time ago is K and W are silent letters in English and that’s why they’re chosen. But I’ve never heard of a radio station that didn’t spell out its name and omit the W or K from the pronunciation, so I call “bullshit” on that theory. My hometown radio station was KDIO (Ortonville MN) which I thought was an interesting rhyme for RADIO. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [April 20, 2015, 9:29pm UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/19 "2015-04-20T21:29:32Z")
Besides KDKA Pittsburgh that Cecil mentioned there is also KYW Philadelphia which is currently shown as a CBS station, which it wasn’t when I was growing up. I have a dim memory, it was NBC and WCAU was the CBS affiliate (it still is; I just googled it). When KYW started a TV station, they wouldn’t let it be called KYW-TV (at least it wasn’t called that) and used WPTZ. Now I have seen that WPTZ is a Plattsburgh station (how reasonable) and the original KYW TV station is now called–surprise–KYW-TV. Will wonders never cease? ---
**Author:** ![ZurBob](https://avatars.discourse-cdn.com/v4/letter/z/71e660/32.png) [@ZurBob](https://boards.straightdope.com/u/ZurBob)\ **Post date:** [April 21, 2015, 1:25am UTC](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071/20 "2015-04-21T01:25:15Z")
> [@whitetho](#): > > That is a copy from ten years ago, and I update the page on my site annually, so if you are interested in what has changed in the last 10 years (ans: not much) then here is a link to the January 1, 2015 edition: [K/W Call Letters in the United States](http://earlyradiohistory.us/kwtrivia.htm). You have a very interesting site! If you care, an addition to your listing you might consider: WLPI-KLPI Ruston, Louisiana. I was a DJ there in the early '70s while a student at Louisiana Tech. WLPI-AM went off air in '74, but KLPI-FM carries on. BTW: I DXed a lot when I was a kid, and Whites Radio Log was my Bible … Any Info on what became of it would be greatly appreciated. [Next page](https://boards.straightdope.com/t/usa-centric-radio-station-prefix/718071.md?page=2)