FM DXing: Troy’s unexpected catch


Many thanks to SWLing Post contributor, Troy Riedel, who writes:

Thomas, if I were to read this on your blog, I would not have believed the following.

I live in Virginia nearly equidistant from RIC/Richmond Int’l AP (east of Richmond) and PHF AP (in Newport News). I had a 1:40 P.M. doctor’s appt. [July 12] and I took to I-64 East en route to the doctor near Newport News. My Silverado has an XM Radio that I typically listen to, but the reception is bad in the summer because of the wooded nature of the interstate.

I hit the “FM” button and I quickly found a station at 105.7. There were two other 105.7 stations that periodically interfered, but one station was dominating/booming. After music I heard commercials about concerts in Iowa. I heard an Iowa Lottery Commercial. And a Lasik commercial – yes, all from Iowa. I heard a weather forecast that definitely wasn’t for Virginia. After 10-12 minutes I got a station I.D.. It was KSUX Sioux City, Iowa. Sioux City, Iowa is 1,332 miles away or an estimated 22-hour drive!

KSUX dominated the airwaves until I got very close to my Newport News, VA appt. By then (around 12:55 P.M.) I had picked-up one of the other two stations that were competing on 105.7. It was a station on the Outer Banks, NC (about 2.5 hours by car away).

When I went back to my Silverado at exactly 2 P.M., the KSUX was barely audible as the Outer Banks, NC station was now the most clear. I drove back towards my home on I-64 West and after a few miles (5-10 at most) the third of the three stations became clear. The third station was “Kiss 105.7” originating in Richmond, VA. That means the Sioux City, Iowa station, 1,332-miles away, had obliterated the Richmond, VA signal from 12:30 P.M. to almost 1:00 P.M. even though at this juncture of my drive Richmond was 45-55 miles away.

The KSUX Sioux City, IA station … even though weak on the drive home … still occasionally popped through the airwaves to cause interference with the Richmond, VA signal.

If I hadn’t heard it, I would have never believed it. I did a quick check and I didn’t see anything regarding closer stations possibly simulcasting the KSUX signal. It appears to be 100% legit.

I’m dumbfounded. It’s a head scratcher for sure.

Thanks for sharing your experience, Troy. You, sir, were the recipient of some excellent FM DX openings!

FM DXing conditions

There are a few conditions that make for proper FM DX:

  1. Sporadic-E and tropospheric ducting (DXers often call this, “Tropo”)
  2. Meteor scatter, where signals bounce off of ionized trails left by meteors
  3. Also, when there is exceptionally high sunspot activity, FM signals have been known to bounce off the ionosphere (like shortwave signals)

I strongly suspect you were enjoying FM DX from sporadic E. If memory serves (and keep in mind, I’m currently vacationing in an off-grid cabin without Internet), we had a K Index of 5 or so on July 12–at least, I believe I heard a ham radio operator report this on 40 meters that day. I can confirm that the HF bands were absolutely obliterated parts of that particular day. Conditions were very unsettled for the HF (high-frequency) bands, but potentially excellent for sporadic E.

Source: Wikimedia

Source: Wikimedia

Fred Osterman writes about Sporadic E on

Sporadic-E propagation is caused by patches of intense ionization in the E-layer of the ionosphere (approximately 35 to 60 miles above the Earth’s surface). Signals on frequencies above 30 MHz normally pass through the ionosphere and into space. However, sporadic-E “clouds” are capable of refracting such signals back to Earth. The term “clouds” is an apt way to describe the patches of highly charged particles that form during a sporadic-E event. Like clouds, these patches move and are highly irregular in size and shape. It is possible to track the movement of a sporadic-E “cloud” by noting the locations of stations that fade in and out on a frequency as the cloud moves.

Sporadic-E propagation can occur any time of day or year. However, sporadic-E is most common from about mid-May to late July, with another peak a week before and after the winter solstice. Sporadic-E seems to be most common from about mid-morning to noon, local time, and again from late afternoon through the evening hours.

If you’re interested in chasing a little FM DX (’tis the season–!), read Fred’s full article about FM and TV DXing on What I like about Fred’s article is that it’s simple and easy to understand.

Post readers: Has anyone else enjoyed a little FM DX this summer? Please comment! This is a part of the DXing hobby that I rarely feature on the SWLing Post, but would love to highlight more often. Let me know if you’d like to write a guest post on this topic!

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11 thoughts on “FM DXing: Troy’s unexpected catch

  1. Moshe Ze'ev Zaharia

    Wow! amazing stories!
    Mine goes back to high school days, about 30 years ago.
    Back then I was SWLing (thinking I am the only one doing so), and as any teenager back then, I used to tape current hits no matter if it was on AM or FM. back then I didn’t knew much about propagation so I didn’t fully realizes the next thing: as I scanned the FM band with my boombox (simple one with manual tuning), Ice House “Electric Blue” started playing on some new station, so I hit record, the stereo was locked very well.
    As the song faded out I stopped recording, and then came the station ID, and it was an Australian station! It disappeared in the middle of the next song, to never be heard again.
    Since I live in southern Israel, Australia on FM is once in a lifetime DX…
    Sometimes I can get Greek and Turkish stations on my Sangean but no more Australia ):

    Best Regards,

  2. DL4NO

    Here in southern Germany I have heard Spanish and even Arabic stations on FM. The Arabic stations appeared nearly at the same time as Spanish ones so I suspect I heard stations from Tunesia or so.

    Here in middle Europe the FM band is extremely crowded. Therefore an SDR is very helpful for DXing: You can reduce the bandwith to 50 kHz or even less. Of course this leads to audio distortions. But at 100 kHz these are not that bad and while you urgently wait for a station ID, an avid DXer will tolerate it.

    My SDRplay SDR brings in Austrian and Swiss stations I cannot hear on any of my other receivers. A good directional antenna might help but my limited air space is reserved for ham radio 🙂

  3. Michael Black

    I don’t remember details, though I wrote it down somewhere. Ten or fifteen years ago, I turned on the radio about 9am. It was a hot summer day in July. I was using a Delco digitally tuned car radio withdrawn power supply, the antenna might have been a few feet of wire behind the radio, but I think by ten it was a dipole mounted inside at ceiling level. There were a couple of not quite local stations that would come in at times, and I had them on presets. I’d routinely check them when I turned on the radio, it took so little effort. That morning something was different, I can’t remember if one or both of those stations were coming in, or I heard something else. So I probably started tuning. And I hear a station in Mississippi, booming in. I’m in Montreal. There were some other stations I heard, but I’m not sure I id’d them, you need to work fast, but getting an ID takes time. At least with the digital tuning, I could get t frequencies right. And then it was over, me wondering if I turned on the radio t the right time, or ifI’d missed most of it before the radio was on.

    Memory says one of the signals swamped a local station, ie one that could be heard all the time but was weaker.

    It was great, and like the minor earthquakes we get here, it’s over before you fully realize what’s happening.

    Sadly, the “empty” frequencies on the FM band here have been filled, so the incentive to check empty frequencies is gone. We can’t get that PBS station and two commercial stations which would only be receivable some of the time, which were stations I wanted to hear. So I’m not checking the band.


  4. Troy Riedel

    Hello All,

    Thanks for your posts … all are very interesting.

    Though I’ve done AM DX’ing, I have never done it on the FM band. After capturing the KSUX signal from Southeast VA, I will now try it regularly.


  5. Tha Dood

    DX FM on a walkman? Done it!!!! It was July 4th 1987 and I was vacationing up in Alexandria Bay, NY and Kingston, ON, Canada. I was listening to one of those Top 100 Rock countdowns on a GE AM / FM / cassette walkman that kicks-ass over many portables today. (I still have it! The tuner works, but not the cassette.) Anyways, Sporadic “E” really kicked up where a Christian station in Texas captured right over it! I use to TV DX those analog CH’s 2 – 6 as well. It seems that Sporadic “E” was more intense back in the 1980’s. Happy DX’ing!!!!!!

  6. Curt Schwarzwalder

    Here in Northeast PA, it has been quiet for FM broadcast band DXing so far this summer until yesterday, when I heard a commercial for an Alabama River Festival on a usually locally vacant frequency- on a Walkman! It faded before I could get an ID. As Thomas said, ” ’tis the season-!”

  7. Alex

    In Greece I received today on oirt band 65-74 mhz radio stations from Russia. Few days ago I received Italian stations and few weeks ago from France and middle east. All in fm.

  8. Tom Servo

    I live on the Alabama coast near the Gulf of Mexico and tropospheric ducting and enhancement is a typical summertime thing, but I never seem to luck out and hear anything really wild. This summer has been almost a complete bust for me. A friend of mine in Florence, Alabama (opposite end of the state) recently logged several stations in Colorado and one in Wyoming and posted some videos about it:

    He did it with nothing more than an Insignia tabletop radio on the second floor of his home, proof that one doesn’t need a high gain FM yagi or a high dollar receiver! This comes on the heels of his reception of several radio stations out of northwestern Mexico a few weeks before.

    In years past I’ve logged Mexico, South Dakota and Minnesota from central Alabama, as well as Quebec City. I’ve also gotten clear HD reception from KZRR in Albuquerque in north-central Mississippi. But nothing that far since I moved to the coast. Maybe one day I’ll get luck; FM DX interests me as much if not more than shortwave DX.

  9. Tha Dood

    This has not happened very often this year, to my disappointment. A couple of times in the truck I would be trying to tune into our local LPFM station on 88.1FM, and heard Oklahoma NPR. Car stereos are great for this with most of them having 1/4-wave antennas on them for FM band. About a week and a 1/2 ago, I was in a parking lot on lunch break and on 88.1FM came in a Walk-FM affiliate in Nebraska. Tuesday, 7/12/2016, I was finally home when that “E” opening happened and work on 6M SSB TX, MS, AL, then NJ, E. PA, Queens, NY, then Albany, NY, then Orchard Park, NY (A dude I remember QSO’ing with on 2M repeaters years ago!), then WI, then 6M fell out. However, 10M SSB and 10M FM still kicked on through then late evening, thus I worked MN, WI again, KS, OK, then end where I’ve started back in TX. Wow!!! Full circle that day. Dee, and I’ve only waited for like a full year for that. Now, if we can again get a superb temperature inversion, like we had in late September 2004, to have fun with VHF and UHF DX, that would make this year more complete. I can only hope.


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