I do a lot of driving in my 2006 Mazda MPV minivan in Ottawa, Canada, two hours' drive west of Montreal. Being a long-time radio reporter/broadcaster, I pass the time by tuning across the AM dial. For some odd reason, it gives me a great deal of satisfaction to hear the New York City traffic reports on WCBS-880 — perhaps because I'm far away from Manhattan gridlock.
This map shows stations heard by the author on his Mazda's stock radio while driving in and around Ottawa. A few months ago, I decided to check out the AM band methodically, to find out which U.S. AM stations I could hear in Canada.
My best tuning typically was at night, when WCBS booms in as clearly as my local news station, CFRA-580 Ottawa. But it didn't take long for me to find other distant U.S. stations breaking through.
Over the next few weeks, I heard WGN-720 Chicago; KMOX-1120 St. Louis; WCCO-830 Minneapolis; WFED-1500 Washington; WRVA-1140 Richmond, Va.; WHAS-840 Louisville, Ky.: WLW-700 Cincinnati; WBT-1110 Charlotte, N.C.; WWVA-1170 Wheeling, W.Va.; and my most distant catch, WSB-750 Atlanta. As the radio crow flies, Atlanta is 935 miles from Ottawa.
Why is it possible for me to hear so many distant U.S. stations (and some Canadian) here in the Great White North? Moreover, does it matter to stations such as WSB and WGN that distant listeners can hear them?
As most Radio World readers will know, what I was doing in tuning around the dial is AM DXing.
Wayne Heinen is chairman of the National Radio Club. DX is a radio hobbyist acronym for long distance. Since the earliest days of radio, AM DXers have "surfed" the AM band, trying to hear distant stations.
When they hear a distant station's call sign, DXers write it down along with details of what's being played on air, the time and date. They send that information to the station in hopes of having their "reception reports" verified by the station's engineer. Such requests and confirmations are known as QSLs. (Ham operators exchange them too.)
Even in the Internet Age, there are AM DXers who scan the band for "catches." At Tribune station WGN in Chicago, for instance, "I receive 10 to 15 DX letters each year," says Director of Engineering James J. Carollo.
"It is quite normal during winter months to receive five or six letters from European countries, especially Denmark, Finland and Sweden. DXing is quite popular in those countries. They seem to enjoy taking vacations to remote cabins on the tundra specifically to capture remote signals from North America."
Today, it is common for DXers to send audio clips by e-mail to prove their reception, rather than handwritten logs by paper mail.
"I send each of them a QSL card and a small promotional item, usually a static sticker with our logo on it," Carollo said. "They delight in sending letters describing themselves and their families, and they take the time to explain quite a bit about their communities and lifestyle. I find it quite enjoyable to correspond with them."
Medium-wave propagation characteristics make DXing an endeavor best done in the dark.
During daylight hours, a component of AM and shortwave radio signals called the ground wave travels from tower to receivers, in a generally predictable manner. A secondary component, the sky wave, travels off the planet into space.
At night (and occasionally during the day), things change. The layered ionosphere, which has been charged by the sun's rays, begins to act more like a mirror.
"When this happens, AM radio signals begin to bounce off the ionosphere, and the angle of their reflection causes them to land back on the planet at a considerable distance from the tower," says Wayne Heinen, chairman of the National Radio Club, a hobbyist organization that includes AM DXers. "This is why you can hear WSB Atlanta in Ottawa, Canada." (FM and TV signals exhibit their own characteristic reflection qualities.)
From Finland and Back Marko Rossinen, who lives in the small community of Rautavaara in eastern Finland and has been DXing for more than 26 years, e-mailed KMOX in St. Louis in January seeking reception confirmation.
"In the winter it's quite usual that North American medium-wave stations can be heard here in Finland," he wrote to the station. "But this is not a daily phenomena — reception varies usually in the cycles of one month and in the longer term in the cycles of 11 years because of [the] sun's activity and sunspots. The sunspot minimum was reached in April 2009 and the next minimum will be in 2018."
Rossinen provided a description of the geography and history of Finland — "maybe the best known Finnish product are Nokia's mobile phones. Nokia is also the biggest enterprise in Finland and its headquarters is situated in Espoo" — as well as a discussion of Finnish emigration to North America.
He then reported that he "had the pleasure of listening to your station KMOX broadcasting on 1120 kHz in the 267.86 meter band on the 29th of December 2009 at 10:10–10:36 p.m. Central Standard Time." He provided a description of the programming (a call-in show about hockey, plus spots), and he rated the signal strength, interference, noise, propagation disturbance and overall "merit" of the reception on his Japan Radio Corp. receiver and 100 meter wire antenna.
KMOX and Engineer Paul J. Grundhauser e-mailed back:
Thank you for your letter to KMOX Radio. It's great to hear from our listeners all across the country and around the world. Your reception report has been checked, and has been found to be accurate; you may consider this letter your verification certificate.
Here is some technical information about KMOX Radio:
Frequency: 1120 kHz
Power: 50,000 watts, unlimited hours of operation
FCC Classification: 1A (Clear Channel)
Main: Harris 3DX-50, 50,000 watts
Alternate Main: Harris DX-50, 50,000 watts
Main: 476 feet, vertical guyed tower located in Pontoon Beach, Ill., on 45 acres
Auxiliary: 190 feet, vertical guyed tower, co-located with the main tower in Pontoon Beach, Ill.
KMOX signed on the air on Dec. 24, 1925, and has been in its present transmitter location since 1945. KMOX is owned by CBS Inc., and consistently reaches into approximately 45 states, and around the globe.
Thanks again for writing us. In the early days of radio, engineers liked to receive DX reception reports, especially if they worked at high-powered "clear channel" AM stations whose frequencies were licensed to reach great distances, in part to serve rural areas reliably at night.
DX reports proved that these transmitters were operating properly and gave station salespeople anecdotal support in their efforts to attract national advertisers.
Radio in the United States has now evolved into what is largely a locally-oriented medium. While some voices still press for AM regulation to protect their regional or national footprints, the business and regulatory emphasis in the 21st century tends to be about stations' local reach, even when those stations include syndicated content and national ads in their mix.
This begs the question: What are DX reception reports worth to today's AM engineers? Sadly, not much, according to Director of Engineering Charles Kinney at Cox station WSB.
"From an engineering standpoint, they have no importance," he tells Radio World. "But it is still nice to know that people are hearing us in Western Europe and even South Africa. Even today, I still get two or three reception reports a month, and we do send out QSLs to confirm them."
At CBS station KMOX in St. Louis, "We get reception reports from Europe, but not that many from the United States anymore," says Paul Grundhauser, station engineer.
"It is getting harder for people to hear us due to more stations being allowed on clear-channel frequencies. As well, HD Radio has not made things any easier, since these signals cause interference to the analog signals on the AM band.
"This said, reception reports really don't affect how we do things at KMOX, in terms of our transmitter and antenna. I don't think it has an effect on sales either."
Most of today's AM broadcasters may not care that their signals are reaching past their local coverage areas, but it appears that DXers will keep tuning in and telling them so.
"This hobby is alive and well," says NRC's Heinen. "Even with the Internet and satellite TV, there are still people who enjoy hearing AM stations hundreds and even thousands of miles away." The NRC encourages stations to broadcast "DX tests" during their overnight maintenance periods, when it's possible fewer stations are on the air on their frequencies.
The most dedicated AM DXers use specialized radios and antennas to improve their catches. They might travel to "electronically quiet" rural sites for better reception. In Norway, some even venture out on the ice in winter, where electrical noise is nil.
In my case, I tune in on my stock Mazda radio using my factory-installed antenna. Yet, as the Google Earth image included with this report shows, the number of AM stations I can receive is astounding.
Granted, many are buried in noise and cross-talk from other stations. But when I need to feel better about living away from New York's bright lights, I can reliably tune to WCBS's traffic reports. That always helps.
Does your station hear from DXers? Tell us about it. Write firstname.lastname@example.org.