US AM radio stations are required by law to self-identify in English as close to the top-of-the-hour as possible during a natural station break. The bigger the station (larger stations in bigger markets) the more reliable this will be as they often are carrying syndicated network content that follows a very strict schedule and has specific time allotments for station IDs.  Outside of the U.S. you will find this type of rule can be hit or miss.

​

The below is a great example of what a top-of-the-hour ID will sound like, from 50,000-watt clear channel powerhouse, 870 WWL in New Orleans, LA

​

​

​

But what if you are listening to a station and it isn't the top-of-the-hour, are you going to just have to wait until a new hour to identify?  Of course not.  Many stations will also ID at some point around the bottom-of-the-hour, or at the quarter-hour marks as there are typically commercial breaks around these times.  Going into or coming out of a commercial break, especially one that contains local commercials, is an excellent time to listen for a station ID.

​

In addition to an outright station ID, you can listen for other clues to help you narrow down which station you might be receiving. Depending on the quality of the evidence available to you, you might even be able to positively identify a station without ever hearing them provide their call letters.  

​

Some great examples can include slogans, such as "ESPN Miami," "Newsradio 790", etc.  These can help you narrow down who you are hearing at least to a small handful of stations.  A quick Google search of what slogan you heard can usually point you to your most likely candidate.

​

Local advertisements are also excellent sources of evidentiary material for identifying a station.  Pay particular attention to any phone numbers provided, as they can provide you with a clue on who you are hearing.  While toll-free numbers are not very helpful, numbers with local area codes can be. You may also catch local business names, street addresses or place names which can also be helpful.  If you are hearing clues like "Southern Colorado's tire specialists," you know you are likely looking at a station located somewhere near Southern Colorado (which can include northern New Mexico, southwest Kansas, etc.).

​

Another fantastic clue comes from Public Service Announcements (PSAs).  National PSAs are not helpful, but listen closely when they start listing off "this message is brought to you by.." as you can sometimes pick up something along the lines of "the [insert state name here] association of broadcasters and this station."  If you hear "the Vermont Association of Broadcasters" then that is a very strong clue that the station you are listening to is licensed in the state of Vermont. 

​

Another helpful piece of information can be weather and traffic.  Hear a station giving temperatures in degrees Celsius?  Congrats, you are hearing a non-US station.  Do they mention "76 degrees inland, in the mid-60s at the beaches"?  Then you are hearing a coastal station.  

​

​

​

​

​

In the example above, we hear 680 WPTF in Raleigh, NC and they do give us a few IDs with call letters.  Let's imagine though that they didn't, let's swap out the call letters for "Newsradio 680".  There is still plenty of information in this clip to give us clues that we are hearing a station in Raleigh, North Carolina, which would help us have enough context to narrow down that this was indeed WPTF.

​

Be careful though of syndicated content.  Stations running network programming such as sports talk, political talk shows, etc. will often have syndicated "network commercial breaks" which run the same commercial across all of their stations.  These are easy to pick out as they are for national brand names/companies (Zip Recruiter, Boll & Branch bedsheets, Progressive insurance are all examples from the US that come to mind).  You may hear city names mentioned during syndicated content...don't fall for it being a clue.  Just cause you hear them take a call from "Jerry in Sandusky" doesn't mean you are receiving a station in Ohio.  Listen closely and wait for local ad breaks, between the ads and any station imagine (slogans, etc.) you should be able to suss out who it is.

​

Formats can be helpful for you, but do not rely on them as stations can change their format with little to no warning.  While there are many elements of a radio station governed as part of the license held with their governing body (such as the FCC in the US), station format is NOT one of those.  The FCC doesn't care what your format is as long as you are not broadcasting anything obscene or against FCC rules.  Therefore, a station can change formats sometimes overnight with little to no warning.

​

I was once employed by a large radio station corporation and we launched a complete reformat of a radio station overnight, without telling any one.  Listeners were shocked and local media was playing catch up trying to get the story out about what happened to that little AM station that all of the sudden was broadcasting a new format.  

​

Some formats can be more helpful than others.  Sports talk will not get you far as there are usually at least 2-4 sports talk stations on most frequencies. However, a station with programming in French is very noticeable and something that likely wouldn't change often.  It can be a great indicator of who you are receiving.  Below is a clip of a Canadian French-speaking station, 860 CJBC in Toronto, ON, that stands out pretty easily from the rest of the stations on the frequency.  Not just because they are dominant on the freq and loud, but because they are the only French station we hear and the station in question is a French formatted station.

​

​

​

​

​

​

Finally, you can also try to "parallel" a station to their online stream to see if programming details match.  Be careful, though, like we discussed above, syndicated programming is not a good indicator of station identification because any station on that frequency running that network will have the same content. As an example, if you are tuning in an ESPN station, the online stream will just confirm it is an ESPN program.  It will not help you confirm it is the ESPN station in Milwaukee when there are also ESPN stations in Buffalo and Dallas on the same frequency that you could be receiving.  Also, many stations will run special 'online-only' commercial breaks so advertising may be different online compared to over-the-air.  However, if you hear non-syndicated and distinct programming content, that can be an excellent clue that you are receiving the station in question.  Note, they will usually have a delay that can run anywhere from a few seconds to a minute or longer between the on-air signal you are receiving and the online stream.

​

In the example video provided below, we hear 1120 WMSW in Hatillo, Puerto Rico weak under a dominant 1120 KMOX in St. Louis, MO.  However, we hear just enough very distinct audio to run a comparison with their online stream to get an exact match that validates the station heard as being the Puerto Rican.  Notice also the slight delay, this is actually a very short one.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

Sometimes, you cannot find an online stream for the target station.  In those situations, you can use an online receiver/Web SDR that is located near the target station to try to compare what is being received in that location to your location.  This is demonstrated in the clip below, where we have a received audio in Charleston, SC for what we believe is coming from YVMN, Radio Coro, in Coro, Venezuela.  I was able to use an online receiver located in Bonaire, which is located just off the coast of Venezuela and has a nearly line-of-sight from Coro to Bonaire.  As such, YVMN should be dominating the Web SDR in Bonaire on 780 kHz.  In the clip, we see that it is and contains a direct match for received audio on my local SDR in Charleston.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

If non-domestic stations are your target, there are a couple of things to look out for.  In the United States, I listen for what are known as "latin nights."  If I hear certain frequencies where there are usually loud domestic stations to be found, but on a given night they have been overtaken by Spanish-speaking stations, I know that conditions are favorable to Latin America.  So, I will search for other Latin American stations and try to determine just how deep (far South) the opening is going. 

​

The below clip is a great example of what one might hear during a "latin night".  Here, 640 Radio Progresso in Cuba is dominating the frequency.  While this can be common in some Southern US locations, for others this would be abnormal.  If you are hearing latin stations this strongly, over the top of all other domestics on channel, it is a good idea to tune around a bit including to normal "clear channel" stations to see if you are hearing other stations from Latin America.

​

​

​

​

Another good example of what one might hear in a "latin night" would be stations from deeper into Latin America, such as those found in South America.  Below, a station in Colombia is heard, dominating 650 kHz over usual dominant American domestic, WSM in Nashville, Tennessee.  The presence of Colombia so strongly is an indicator that other Latin American stations may be audible.'

​

​

​

​

​

​

​

One night I remember fondly is when 840-WHAS in Louisville, Kentucky was going to be going off-air for transmitter maintenance on a Sunday evening.  So I tuned on to frequency and waited.  Even before they powered down, 4VEH in Haiti was already overtaking the frequency, dominating with what wounded like a religious sermon in French.  Sure enough, there were other stations from Latin America that were strong that night as I also logged two stations in Colombia I had not heard before, several new stations in Cuba and soon after, logged my first station from Venezuela.  

​

If you are looking for Transoceanic stations, then you are looking for "hets".  Heterodynes or "hets" are high pitched tones caused by carrier frequencies that are just off of the frequency you are tuned to.  While in North and South America, radio stations are separated by 10 kHz of spacing (550, 560, 570), outside of those areas, stations are separated by 9 kHz of spacing (531, 540, 549).  As such, on some frequencies, these "split frequencies" can appear on your radio dial as a heterodyne. 

For instance, on the East Coast, especially during autumn and winter months, you can tune to 890 kHz during the early evening hours and hear a strong 1 kHz het from 891-Algeria.   If the signal from Algeria is strong enough, you can even tune to 891 to see if any programming audio is coming through to help you positively identify them!

​

In the clip below, we hear an example of that exact heterodyne on 890 kHz from 891 Chaine 1 in Algeria.  This was received using a car radio on Sullivan's Island, SC in January of 2020:

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

I

n the clip below, we hear audio from 531 kHz, Jil FM in Algeria received from a coastal campground just outside of Charleston, SC.  You can see on the waterfall the clear markers of audio on both 530 kHz and on 531, and we actually hear the audio on 531.  

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

On the left hand side of the screen at the top of this section is a link to "Trans-Atlantic Best Bets" compiled by AM DXers Jim Nall, Tim Tromp, Marc DeLorenzo and Allen Willie.  All are well known names in the world of Trans-oceanic DX  They provide a list of stations as well as tips on equipment, time of year and time of day for trying to snag a Trans-Atlantic station - even for DXers far well inland!

​

Another thing that you will definitely want to keep an eye/ear out for are DX Tests.  While not as prevalent as they were 20 years ago, there are still a handful of DX Tests each year that provide DXers with opportunities to hear difficult or highly sought after stations, states, etc.

​

These DX Tests are coordinated often by the DX Clubs or by volunteers with contacts at various stations.  The station engineering staff will often use a DX Test to conduct transmitter maintenance, calibration, etc.

​

During a DX Test, expect to hear completely out-of-the-ordinary programming.  Usual fare will include morse code IDs, various tones, odd music such as marching bands, etc.  The goal is to provide programming that is going to be easily noticeable and most likely, easier to cut through the static.  A morse code signal will travel a bit further and propagate a bit easier than a voice signal does, simply because it stands out of the noise floor much easier.

​

One example is from the 2020 DX season, there was a DX test for 880 KJJR in Whitefish, Montana.  It was a last minute DX Test late in the season (early May) but provided an opportunity for many that normally cannot hear stations in Montana (such as those of us on the East Coast of the US) to log a Montana station.  Sure enough, in the wee hours of the morning on May 2, 2020, morse code and various tones from the KJJR DX Test made their way through my W6LVP loop antenna into my RSPdx SDR.  Between the visual clues visible on my SDR software waterfall and the actual heard audio under dominant WCBS in New York, I was able to confirm reception of KJJR providing me with a new state heard in Charleston!  The video below provides the samples of the audio that was recevied.

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​

​