Sunday, December 19, 2010

Early Mediumwave QSLs

For many years radio hobbyists have collected QSLs, or verification cards and letters from stations they have heard. These items offer proof of reception of the station, and are often sent out by the station engineer upon receipt of a letter showing detailed reception information. Back in the 1920s when radio was the new rage across the country and people of all kinds were delighting in seeing how far they could hear, the EKKO Company of Chicago, Illinois, had a novel idea to produce reception verification stamps. Looking much like postage stamps - perforated, engraved, and in various colors - they were printed with station call letters, and EKKO even produced an album - selling for $1.75 - to paste them into. The reason? It was wonderful advertisement for EKKO's phonograph, record, and radio accessory products.

EKKO contracted the American Bank Note Company to produce the stamps, a company which already produced stamps for the US Post Office. The stamps for US stations framed the American bald eagle with two radio towers in the background. Stamps for Canadian stations substituted the beaver for the bald eagle. All stamps had a station bar below where the broadcast station call letters could be imprinted. EKKO's initials, E-K-K-O, were displayed on the four outer corners of the stamp. The stamps were purchased by the radio stations from the EKKO Company, and then, when their respective listeners provided written information identifying reception details of a particular broadcast, the station would send the listener a Verified Reception Stamp with the station's call letters.

The 1924 album marked the year when EKKO sold stamps to 592 stations in the United States and Canada, and at the height of the collecting craze they were selling their stamps simultaneously to more than 650 broadcast stations located throughout North America and the Caribbean! Independent research has identified over 844 stations that participated in the program between 1921 and 1929. These stations were located in the United States, Canada, Cuba and Mexico.

As the Great Depression settled upon America in the 1930s, the EKKO Company, like so many others, faded away as did the EKKO Verified Reception Stamp. Until recent years, the stamps have remained merely a curiosity among stamp collectors (called "Cinderellas"), but since 1980 interest in them has increased, and some have become quite valuable.

For more information on EKKO Verified Reception Stamps, see the following articles:

What's An EKKO Stamp?

Antique Radio

Monday, November 15, 2010

A 6-Inch Tunable Loopstick

The homemade tunable loopstick device, similar to the Q-Stick by DXTools continues to be a popular article on RADIO-TIMETRAVELLER. Let's revisit this simple device and build another one, this time a 6-inch version.

Old transistor or table radios can be had for almost nothing at your local yard sale or flea market. I have reported on yard sales and flea markets before. Great radio values can be had from uninformed sellers.

Don't Laugh at Yard Sales
Another Deal, The Panasonic RF-565
Viva Flea Markets

I always keep my eye out for both working and non-working varieties, as the non-working ones can be stripped for their parts. Most important for building a tuning device: the variable capacitor and the ferrite loopstick.

The better buys are the radios having longer loopsticks or serviceable tuning capacitors. Many pocket radios are configured with the tuning knob directly connected to the capacitor, though the capacitor itself is often small in this case. Larger radio varieties often have a slide rule type dial mechanism, usually driving a more substantial capacitor. Surprisingly, most tuning capacitors in old radios, even the small ones, have 1/4 inch shafts, though short. So if the main tuning knob is intact and is one which is connected directly to the capacitor shaft, all the better. Save the knob.

This summer's flea market take was four old transistor radios. One was pocket sized, and the others were the type you would set on a desk, about the size of a small book. Three of the four had seen better days and did not even work. The other actually worked decently enough to keep and experiment with. Each cost two dollars or less.

The best loopstick of the bunch was a nice six inch one, a rod instead of a bar, wound very nicely with evenly-spaced turns of Litz wire to about 80 percent the full length of the stick. A short IF coil was at one end. I carefully removed the IF coil, as it is not needed.

I selected a small tuning capacitor which had a nice dial knob. At the end of the loopstick where there was room, I taped the capacitor to it by slotting the tape with a razor so it would fit over the shaft. The capacitor could also be hot glued to the rod if desired.

The coil wires were then carefully soldered to the center and edge terminals of the capacitor, forming the parallel tuned circuit. Be sure to use the edge terminal having the greatest capacitance, as the other one is the IF side of the capacitor with lesser capacitance. If you want to get fancy, you could enclose the loopstick device in a short length of PVC pipe, capping the coil end, and fastening the tuning capacitor on the other end of the pipe.

To use the loopstick, simply hold it parallel and near to the internal loop in your radio, then tune it to peak the signal your radio is tuned to. Rotate the two together, radio and loopstick, for maximum signal. The loopstick can also be rotated independently to null an offending co-channel station. A short length of wire or even a longwire could also be attached to one of the capacitor terminals, providing more signal, though it will lessen the directivity of the loopstick.

Sunday, November 7, 2010

KDKA Turns 90 Years Old

In 1920, Dr. Frank Conrad was an engineer in the employ of the Westinghouse Electric Company. He was also an amateur radio operator. With the release by Congress in July 1919 of all privately held radio and telephone equipment now that World War I had ended, the race to commercialize the new science of radio telephony was on.

To test transmissions during the war, Conrad placed one transmitter and receiver at the Westinghouse plant and another above his garage at home, four miles away. When the war ended and the government lifted the restrictions on amateur radio telephony, Conrad went back to his experimentation from home.

After the war, a fierce battle ensued between the US government and the Department of the Navy over control of the airwaves. The government won out and settled on the Department of Commerce to run things, wresting control from the Navy's hands. After the dust cleared, in April 1920, Conrad applied to the Department of Commerce to license his station. He was given the call letters 8XK.

Westinghouse saw that Conrad's experiments might be important and potentially profitable, and so with Conrad's help, started construction of a new transmitting facility on the roof of the Westinghouse plant in East Pittsburgh, PA. A presidential election campaign was in full progress that year, the election of 1920. The Republican ticket, comprised of Senator Warren G. Harding of Ohio and Governor Calvin Coolidge of Massachusetts was paired against the Democratic ticket's Governor James Cox of Ohio and former under secretary of the navy Franklin Delano Roosevelt.

On October 27, 1920, Westinghouse's radio facility was completed, and the Department of Commerce granted it the historic call sign KDKA. It transmitted on a frequency of 833 KHz (360 meters) with a power of 100 watts. Only two frequencies were assigned for broadcasting at this time. The other was 619 KHz (485 meters).

Hastily constructed, the "radio facility" was hardly more than a simple metal shack with all the necessary wires and equipment, and a desk from which an announcer could report election results. The election was slated for November 2.

On Tuesday, November 2, 1920, election night, up in that metal shack four men in dark suits compiled election returns received via wired-telephone from the newsroom at the Pittsburgh Post. The results were handed to one Leo H. Rosenburg. Leaning forward into an early microphone, Rosenburg's voice was sent through wires and apparatus out into the ether. It is estimated that between 500 and 1000 listeners heard this broadcast.

The excitement triggered by KDKA's 1920 election coverage set off a national hysteria for radio. Within weeks, Conrad had upped KDKA's power to 500 watts. It was now being heard as far away as Washington, D.C. Conrad started adding entertainment programs according to a schedule. Radio broadcasting, as we know it, was born.

Happy birthday KDKA-1020, Pittsburgh, PA, now 50,000 watts!

The Aeriola Senior regenerative radio.
Introduced December, 1921. $65.00

Sunday, October 31, 2010

DXing From The Road, Fall 2010

I am currently in southwestern Arizona after crossing the country from Rochester, New York in the last few days of September and the first part of October. Of course I did some mediumwave DXing along the way. The general route was I-90 to Cleveland, I-71 to Columbus, then I-70 all the way into Denver, cutting through St. Louis and Kansas City. From Denver I drove again via I-70 on to Moab, Utah, then south on US 191/163 through red rock canyon country across the Navajo reservation to Flagstaff, AZ, then on from there. Pictured is graveyarder KCPX-1490 (1KW) in Spanish Valley, Utah, ten miles south of Moab.

Here are some DXing highlights from the trip. Note that I did day-to-day checking on some regulars like KOA-850, Denver, and R. Enciclopedia-530, Havana, Cuba. Some may find this redundant; I find it is interesting to see how propagation changes in reception of these stations as you cross the country. Mileages are from the reception point indicated. Times are local (L). The Tecsun PL-380 was barefoot.

Monday, September 27.

First day out. Rain all day, and lots of highway construction, typical. On the truck radio, all across I-90 in northern Pennsylvania and Ohio, boomer KDKA-1020, Pittsburgh, PA (50KW) comes in quite nicely (about 100 miles distant). Best listening station in this area is WKTX-830 (1KW), Cortland, OH, daytime only. It is locally owned, proud of it, and plays a nice variety of old music, mostly 1950s. I wish there were more of these locally owned stations.

Stressed from the rain, I moteled it in Mansfield, Ohio, about 50 miles south of Cleveland. I found myself only one-half mile from Mansfield's own graveyarder WMAN-1400 (1KW). The PL-380 desensed a little on the nearby adjacent channels due to the big signal, but reception was not affected out past +/-30 KHz or so.

Tuesday, September 28. Mansfield, Ohio.

Same night, Monday night after midnight actually. I woke up just after midnight and decided to do a little motel DXing with the PL-380.

0015L WHLO-640, Akron, OH (500W). 51 miles.
0028L R. Rebelde-600, Cuba. Latest location info I have shows Holguin, Cuba, 1424 miles. Good signal.
0033L CIAO-530, Brampton, ON. 237 miles. East Indian music.
0043L WMOB-1360, Mobile, AL (212W). 760 miles. Good catch for low power.

Up again at 0515L, getting ready to hit the road. Raining hard. PL-380.

0531L R. Enciclopedia-530, Havana, Cuba. 1223 miles. Great signal.
0540L KVNS-1700, Brownsville, TX (880W). 1337 miles. Another good catch for low power.
0605L KOA-850, Denver, CO (50KW). 1173 miles.
0645L WTRU-830, Kernersville, NC (10KW). 340 miles. "The Truth", over WCCO-830, Minneapolis, MN.
0642L WGY-810, Schenectady, NY (50KW). 461 miles.

It is interesting to note that Cuba seems to always boom into Ohio (and Indiana). I have found this to be the case on all my trips through the midwest. Cuba is much weaker in Rochester, and seasonally sporatic when casually listening without the help of loops, etc.

By Tuesday night I make it all the way to High Hill, Missouri, a quiet exit off of I-70 with two motels and not much else, about 70 miles west of St. Louis. Noise level is low.

Wednesday, September 29. From the motel using the PL-380.

0402L CKDO-1580, Oshawa, ON (10KW). 737 miles.
0404L WZRX-1590, Jackson, MS (1KW). 456 miles.
0408L R. Enciclopedia-530, Havana, Cuba. About 1400 miles. Fair signal, not nearly as good a Ohio-Indiana.
0420L WCBS-880, New York, NY (50KW). 940 miles. Good signal.
0422L KOA-850, Denver, CO (50KW). 717 miles. Strong signal.
0429L WABC-770, New York, NY (50KW). 925 miles.

Wednesday afternoon, using the truck radio. I-70 mile marker 220, central Kansas. It is early afternoon and the sun is high in the sky. Denver is a still long way off, but I find Denver is making a strong daytime DX appearance already. I should have checked these stations 50 or 100 miles ago when I was closer to Kansas City.

KHOW-630 (5KW). 367.5 miles.
KKZN-760 (50KW). 370.0 miles.
KOA-850 (50KW). 356.1 miles.

The surprise here is little KHOW-630 with only 5 kilowatts, received at 367.5 miles. Its signal was better than KKZN-760's 50KW signal! This distance would be impossible during daytime hours on the east coast.

Wednesday night puts me into Hays, Kansas. From the motel using the PL-380.

2059L CBW-900 (CBC), Winnipeg, MB. 761 miles. Interesting interview with Ingrid Betancourt.
2106L WSM-650, Nashville, TN (50KW). 717 miles. Fair signal.
2110L KRSL-990 (30 watts), Russell, Kansas. 27 miles. Weak. Flea power. Much competition from a couple of other unknown stations. Interesting that 30 watts struggles over a distance of only 27 miles at night.

Thursday, September 30. Hays, Kansas. Still at the motel. PL-380.

0420L R. Enciclopedia-530, Havana, Cuba. 1480 miles. Weak.

No more DXing was noted until I hit Utah.

Thursday, October 7. From a desert campsite ten miles north of Moab, Utah. Reception approximately one hour before local sunset time. PL-380.

KKOH-780, Reno, NV (50KW). 541 miles.
WBBM-780, Chicago, IL (50KW). 1161 miles. Weak, under KKOH.
WSM-650, Nashville, TN (50KW). 1271 miles. Mixed with KMTI-650, Manti, UT.

Sunday, October 10. Three miles north of Mexican Hat, Utah. Mexican Hat is about as remote and far away as you can get from mediumwave outlets in this part of the southwest. The closest station is KVFC-740 in Cortez, CO, 73 miles distant, a little 1KW outlet. Big gun KTNN-660 (50KW), The Voice Of The Navajo Nation, is 96 miles, and its not-overpowering -95dBm strength is still heads and shoulders above any other station.

A mid-afternoon low bandscan (530 KHz - 1000 KHz) was done, using the PL-380.

1437L KLLV-550, Breen, CO (1.8KW). 97 miles.
1439L KTNN-660, Window Rock, AZ (50KW). 96 miles. The powerhouse.
1441L KOAL-750, Price, UT (10KW). 173 miles. Weak.
1441L KVFC-740, Cortez, CO (1KW). 73 miles.
1442L KHAC-880, Tse Bonito, NM (10KW). 115 miles. Weak.
1444L KNDN-960, Farmington, NM (5KW). 94 miles. "K-Indian" Navajo station with great country music.

That's it! Only a half a dozen stations could be heard between 530 and 1000 KHz. And about half of them were weak. Talk about a quiet band. Coupled to the 24-inch loop, many more stations were received. It is amazing how much extra signal even a 24-inch loop provides, making a dead band come to life.

It is interesting to bandscan with the PL-380 in such an extremely quiet location. The PL-380 has more whistles, strange whoops and heterodynes than I thought.

Wednesday, September 22, 2010

Hello Everybody! The Dawn Of American Radio

It's that time of year once again when I'm getting ready to head cross country from New York to Arizona for the winter. One of the things I do is stockpile a bunch of books to read through the season. At the top of the radio reading list this year is a book entitled "Hello Everybody! The Dawn of American Radio", by Anthony Rudel. It is the story of the diverse entrepreneurial pioneers of radio, covering the era from 1912 through the 1920s and 1930s. Touching lightly on the technical aspects and inventors of radio, Rudel emphasizes the entrepreneurs and evangelists, hucksters and opportunists who saw the medium's true potential.

From Rudel's website:

"Long before the internet, another young technology was transformed--with help from a colorful collection of eccentrics and visionaries--into a mass medium with the power to connect millions of people.

When amateur enthusiasts began sending fuzzy signals from their garages and rooftops, radio broadcasting was born. Sensing the medium's potential, snake-oil salesmen and preachers took to the air, at once setting early standards for radio programming and making bedlam of the airwaves. Into the chaos stepped a young secretary of commerce, Herbert Hoover, whose passion for organization guided the technology's growth. When a charismatic bandleader named Rudy Vallee created the first on-air variety show and America elected its first true radio president, Franklin Delano Roosevelt, radio had arrived.

With clarity, humor, and an eye for outsized characters forgotten by polite history, Anthony Rudel tells the story of the boisterous years when radio took its place in the nation's living room and forever changed American politics, journalism, and entertainment."

It arrived yesterday and it promises to be a great read. Available from and other booksellers. Published in 2008.

Saturday, September 18, 2010

Signal Patterns

Stephen from San Diego, CA, a reader of Mediumwave Oddities - Transmitter Power, wrote in with the following question:

"What stations actually are authorized with a HIGHER power at night than they are allowed in the daytime? I'll mention one - 760 KFMB San Diego, CA, about 7 miles from me. In the daytime they're only allowed a paltry 5KW omnidirectional, but at night they step up to 50KW."

An interesting question. And you mentioned signal patterns, all-important in the differences between daytime and nighttime mediumwave coverage.

I tweaked my database program Radio Data MW and came up with the following results:

73 US stations run higher power at night than during the day.

KFMB-760, your San Diego station, is the only one which runs 50KW at night and has a lower daytime power. KFMB uses one omnidirectional tower for daytime broadcasting. Power is set at 5KW during daytime broadcasting hours and 50KW at night. KFMB uses three towers at night to get that big 50KW signal out. But the pattern this time is pointed right out into the Pacific Ocean, to the southwest. San Diego's KFMB cardioid pattern has a deep, broad null at 60 degrees, nicely positioned for protection of Detroit Michigan's WJR-760 (50KW) and its western coverage area. Equally important, big gun KKZN-760, Thornton, CO (also 50KW), near Denver at 49 degrees is also protected, as well as a host of smaller US and Mexican stations.

KBRT-740 "K-Brite", a 10KW station in Avalon, on Santa Catalina Island is only a mere 85 miles to the northwest of San Diego's KFMB. It has a three tower array in use both day and night, pointing its signal due east to cover the Los Angeles and Long Beach areas, a scant 26 miles away. KBRT drops its power to a gasping 113 watts at night. Being nearly "co-channel" with KFMB at only 20 KHz removed, inspecting KFMB's pattern plot reveals that that the broad cardoid lobe to the northwest pumps an astonishing effective radiated power of 95KW up a 294 degree vector right at KBRT on Catalina. With a salt water path the whole way, that should be a lot of signal.

The next station with a big signal at night and a smaller one during the day is WLIB-1190 running 10KW daytime and 30KW nighttime, in New York, NY. WLIB uses three towers for daytime broadcasting and four towers at night. Both patterns are generally towards the east, with the nighttime pattern more focused and skewed a little more to the southeast. During the day it competes with WBIS-1190, Annapolis, MD (10KW), and WSDE-1190, Cobleskill, NY (1KW). WLIB's daytime pattern exactly bisects these two challengers on a line right out into the Atlantic Ocean. At night, WLIB only has to contend with New Yorker WSDE, as the Annapolis station is off the air.

The station with the greatest power differential, day to night, is WLAN-1390, Lancaster, PA. They run a mere 18 watts daytime and 1100 watts nighttime, both to a single, omnidirectional tower. Their nighttime power is a remarkable 61.1 times more than their daytime power!

WLAN's main competitor is WZHF-1390 (5KW), in Arlington, VA, a mere 92 miles away to the south-southwest. How does an 1100 watt station co-exist with a 5KW station at night when they are only 92 miles apart? Examining the tower pattern plots, you will find that WLAN in Lancaster, PA is exactly in a deep notch of WZHF's nighttime pattern.

Shown are nighttime pattern plots for San Diego's KFMB-760 and Avalon's KBRT-740, generated by Radio Data MW.

Tuesday, September 14, 2010

Winter DX Season 2010

Great mediumwave conditions were apparent three mornings ago (September 11). I'm an early riser, and at 6AM I'm usually on the way to the coffee shop DXing on the truck radio. Of course at that time of the morning it's still very dark out. The sun doesn't rise here until 6:40L. Tuning to 850 KHz at the top of the hour news, I caught a nice full ID from 50KW KOA-850, Denver, CO (1420 miles) at 0605L. The KOA radiator, a single tower located 30 miles to the southeast in Parker, CO, is a skyscraping 667.9 ft. tall, almost a full 5/8 wavelength in height. As advertised, KOA gets out to some 38 states, and probably more. KOA began broadcasting in 1924.

Back in the late 1970s and early 1980s, I lived a mere 10 miles southeast of this transmitter, out in the rolling eastern plains of Colorado near the town of Elizabeth. I worked in Denver, and would drive past this tower every day (or night) on the way to and from work, often seeing mule deer or prong-horned antelope. Coming from the east, a long hill descended down appropriately-named Hilltop Road, ending at Colorado Highway 83 which ran past the tower. Headed to work one night for the graveyard shift during a blizzard, at midnight I remember becoming disoriented in the whiteout and losing control while descending that hill, shooting straight across highway 83 and through a barbed wire fence, coming to rest in the field right next to the KOA tower. Ah, memories.

KOA is a tough catch here in western New York with nighttime interference from sports stations WKGE-850, Johnstown, PA  (10KW), at 199 miles, and WKNR-850, Cleveland, OH (4.7KW), at 235 miles. Interestingly, on my cross country trip each year I start to hear KOA at night consistently once I get west of Ohio and into Indiana, and under the 1200 mile distance range. I find there's something brick-wallish about that 1200 mile distance in mediumwave DXing.

WWL-870, New Orleans, LA (50KW), 1136 miles, is also appearing almost daily on the 6AM trip. WWL has a two tower antenna array, oriented south-north with major lobes to the northwest, and northeast. The northeast lobe points directly at me. Each of WWL's towers is a full 1/2 wavelength tall. With 3.3 dB gain in my direction, it pumps a healthy effective radiated power of 106KW right up a pipeline to New York. WWL's transmitters are located approximately 2 miles southwest of Estelle, LA, in the Jean Lafitte Preserve, a wetlands. All that water undoubtedly helps too. WWL has been in operation since 1922, predating KOA by two years.

Apparently the winter DX season is upon us once again.

Saturday, August 28, 2010

Early Radio Publications

This week I uncovered a treasure trove of early radio magazines in downloadable PDF format. If you love radio history like I do, you will enjoy browsing through these publications. Two magazines are represented.

Radio Broadcast Magazine, available issues from 1922 through 1930, covers in great detail the early years of broadcasting and includes much technical information for the early experimenter. The advertisements from these years alone are worth checking out. Articles in Radio Broadcast run the entire spectrum from MacMillan's expedition to the Arctic in the summer of 1926 to detailed descriptions of current vacuum tube circuit technology, projects for the amateur, to coverage and questions about governmental standards and practices in this early era of radio, to programming content and personalities. What a wealth of interesting information for the historian!

Radio Broadcast Magazine

Also available on this site is Radio Corporation of America's Radio Age  Magazine, available issues from 1942 through 1957. This was a quarterly publication produced by RCA. A lot of interesting World War II coverage can be found during the war years, as well as new technology.

Radio Age Magazine

Be sure to check these out while they are still available.

Tuesday, August 24, 2010

Internet Radios

I guess I'm too much of an old timer to get into this current Internet "radio" thing. Too many years spent toying with tuned circuits and antennas, too many years a radio DXer, radio listener, even a radio "Ham" - some 47 years - though I really haven't done the Ham thing for some time. WE7W lives on though, and I still keep my license current.

For better or for worse, sometimes words or things in life "evolve" over time to mean different things. I'm thinking radio is becoming one of them. Radio at one time meant "wireless" transmission of electromagnetic waves through the air, from starting point to finishing point. It was picked up magically with a wire or a coiled loop, fed to a tuned circuit which selected one signal out of many, detected and converted to audio which was then amplified so you could hear it. Internet "radio" is no such thing. No aerial, no tuned circuits, no detection. A friend of mine says real radio has to pass through your body (meaning: the waves) - that's the definition of real radio. I say that too, plus a tuned circuit must surely be involved, and almost certainly a detector. Internet "radio" has none of the above. What would Marconi think?

Internet radio probably is radio only in the sense that for a small segment of its "transmission" to you, millions of digital bits are perhaps beamed up to a satellite and back down. Maybe. The rest of its journey, both before and after, it is transmitted through wire or fiber optic cable, passed from one computer device to another to another, arriving in numerical perfection just as it was sent, down to the last, solitary, Boolean bit.

Merriam-Webster says about the noun RADIO:
a: the wireless transmission and reception of electric impulses or signals by means of electromagnetic wave.

b: the use of these waves for the wireless transmission of electric impulses into which sound is converted.
As I was saying: "waves", like the kind that pass through your body.

There was even a time when I used to subscribe to various radio magazines, until the articles became more computer articles than radio articles, each filled mostly with links to web sites. Recent shortwave magazine articles I've seen basically contain narrative on how to navigate a radio station's web site to get its streamed Internet content. Radio magazines have evolved to something different than they once were, too.

I just don't get it. There is no magic for me in Internet radio. See accompanying photo of toaster, er, I mean Internet radio. How about you?

Maybe it's the semantics of the whole thing that bothers me more than anything else. The new "radio" is not the old radio, and never will be. It is something wholly different.

Okay, a reality check. Yes, I do listen to a podcast now and then (now there's a new word unleashed on modern society for you: podcast), or streamed audio via my desktop or laptop. I've even been known to listen to a streamed radio station on occasion (try streamed KTNN-660 sometime, The Navajo Nation, 50KW out of Window Rock, AZ for an interesting experience). But the listening is done for "content", without the accompanied magic of original radio. There is no "feel" to it. I attempted to capture this feel in another post in this blog. I was talking about mediumwave towers:

...."A tower is a thing of beauty to the radio aficionado....Ah, the mediumwave broadcast tower! Think of it! Stately, striped sentinels with strobe lights flashing, they number thousands and thousands across the country, each emitting invisible waves of electrons through the late night air, spanning that mysterious thing called "the ether" to deliver communication to unknown distant masses. It conjures up thoughts of far-away points on the landscape, souls crouched in cramped corners with headsets fixed in the dark of night, straining to make sense of distant babble through static crashes and heterodynes. That would be me. The whistle of a far off freight train gives the same feeling of wonder."

Internet radio does not. Do you like your toast light or dark?

Sunday, August 22, 2010

Mediumwave Oddities - Towers

Today, we move on to tower oddities in the mediumwave broadcast band. Broadcast towers have always been an interesting subject to me. Did you see the news earlier this month on the WWVA-1170 towers collapse, due to severe storms in the Wheeling, WV area? The photo at left shows how they looked in the 1940s. WWVA-1170 started broadcasting in 1926.

Like last time, we will use data from current FCC records dated August 7, 2010. There are 4784 licensed stations in this survey. Previous posts in this series were Mediumwave Oddities - Transmitter Power and Mediumwave Oddities - Geography. Information has been gathered using the Radio Data MW program.

Again, daytime and nighttime data will differ. I will be explicit on which is which when the statistics are presented.


Many mediumwave broadcast stations use multiple tower arrays to direct their signals towards intended markets, or away from other stations which they may cause inteference to. There are thousands of towers out there.

If we total all the towers of all the mediumwave stations transmitting in the daytime, how many would there be?

Answer: 7164. That's a lot of metal in the air.

Out of the 4784 licensed stations, how many stations have only one broadcast tower?

3569 stations have only one broadcast tower, which is 75% of all broadcast facilities. Surprisingly, the remaining 25% actually have more towers total than the single-towered 75%. Multi-towered stations average 2.95 towers per facility.

Essentially, a station with one broadcast tower has an omni-directional signal pattern, in other words, the station broadcasts with equal signal strength in all compass directions. Multiple tower arrays use phasing techniques to form skewed patterns of radiation, often in figure-eight or cardioid shapes. The lobes, or strong points of the pattern are directed towards market areas of interest. The nulls, or weak points of the pattern, are positioned toward areas to lessen interference with other stations or unwanted markets.

Back to tower counts, how many stations have two broadcast towers?

515, or 10.7 percent of the total have two towers.

How about three towers?

384, or 8 percent of the whole. The percentage drops dramatically off from there of course.

Which station has the most broadcast towers in use during daytime hours?

That would be KNTH-1070, Houston, Texas, with 11 towers. They are arranged in an odd grouping of three parallel rows of 3 each, with towers #10 and #11 jammed between the two rows. The rows head generally in a south to north direction. KNTH-1070 uses two less towers (9) during nighttime hours.

Are there more towers in daytime use east of St. Louis, Missouri, or west of St. Louis?

East of St. Louis, there are 4240 towers in use during daytime hours. 2924 towers are used west of St. Louis.

Radio station signal patterns are sometimes further modified at the tower site by what are called "augmentations". Augmentations are modifications to the standard broadcast signal pattern, usually to further null the signal strength in a certain direction to bring it into FCC "signal contour" compliance. An interesting discussion can be found on augmentation over at The Virtual Engineer AM forum.

Stations can have up to 28 augmentations to their signal pattern. This must be a technical nightmare for the broadcast engineer.

Which station has the most augmentations?

Four stations have 28 augmentations in use during daytime hours.


Again, like we saw in Mediumwave Oddities - Transmitter Power, nighttime seems to be the more interesting as it has more odd variety.

How many total towers are used for broadcasting during nighttime hours?

Answer: 7877 towers. 713 more towers are used at night than during the day.

Being a mediumwave DXer, you know that signals travel much farther at night than during the day, commonly upwards of 1,000 miles and more. Stations often must follow different signal pattern guidelines at night to prevent interference to distant stations. This generally requires use of either a different tower arrangement or different number of towers, or both. Stations also may operate at reduced power at night.

Which station has the most broadcast towers in use during nighttime hours?

That would be KFXR-1190, Dallas, Texas, with 12 towers. They are arranged in two parallel rows of 6 each, heading from southeast to northwest. KFXR uses only 4 towers during daytime hours. Texas holds the record for stations with the most broadcast towers for both nighttime and daytime hours. They always do things in a big way in Texas.

Are there more towers in nighttime use east of St. Louis, Missouri, or west of St. Louis?

East of St. Louis, there are 4427 towers in use during nighttime hours. 3450 towers are used west of St. Louis.

Which station has the most augmentations?

Nine stations have 28 augmentations. Among them again is KFXR-1190, Dallas, Texas. I think KFXR-1190 should be considered for the record here. It is the station with the most towers (12) and tied with 8 others with the most augmentations.

I was thinking about ground radials this morning, which are the (generally) buried wires that are placed under broadcast towers to create the artificial ground that they operate over. Usually broadcast towers must have at least 90 quarter-wave length wires, and as many as 120 or more. Seeing as how we know the number of broadcast towers used in nighttime operation, the following question occurred to me:

If we assume 120 radials under each tower, how many total ground radials are in use?

Answer: 945,240. Almost a million radials.

Using an average length of 245 feet for each radial (a quarter wave length at 1000 KHz), how may feet of radials lie under mediumwave broadcast towers in the US?

231,583,800 feet. That is 43,860 miles of wire, enough to encircle the world almost two times. Time to buy stock in copper.

Hope you have enjoyed this series. For more mediumwave oddities on RADIO-TIMETRAVELLER, see the Tower Talk article.

The WWVA-1170 towers after the August 4th, 2010 storm.

Wednesday, August 18, 2010

Australian Mediumwave Database

I came upon an official Australian government link (ACMA - The Australian Communications and Media Authority ) the other day which documents licensed mediumwave stations for Australia in PDF format. Digging deeper, I found an official government database, published in XCEL (.XLS) format. This file has the basic information, such as call sign, frequency, latitude, longitude, power, and service. No tower information is available, and only a crude maximum signal strength of the antenna pattern's maximum lobe is given. It is also a comprehensive file of all Australian transmitter data: MW, FM, and TV. None the less, it will be useful.

Using an XCEL viewer, the mediumwave information can be copied in its entirety and saved as a text file. Further "massaging" can put it into a proper format. Then the information can be incorporated into a database of Australian mediumwave stations. The file is updated once per month.

List of licensed broadcasting transmitters (main page)

Broadcast transmitter data (EXCEL format)

Mediumwave stations, by call sign order (PDF)
Mediumwave stations, by frequency order (PDF)
Mediumwave stations, by area served (PDF)

Tuesday, August 17, 2010

Radio Station Databases 101

Let's explore the details of some of the governmental mediumwave station databases available to us. Much information is there for the taking if you can extract it. But where do we find it? And how do we do that?


Although the FCC's AM Query provides a usable output of AM radio station information, the entire story is not told. Much technical information is left out, particularly field strength, tower, and other engineering data, information which can be found by digging deeper into the actual FCC database files. AM Query is simply a mechanism that extracts predetermined data from the real database, hidden in numerous files in the cellars of the FCC web site. These files are found in the FCC's Consolidated Database System (CDBS) electronic filing system. This database contains some very interesting and useful data.

CDBS file index via http site
CDBS file index via ftp site

If you choose the FTP route, be aware that some modern browsers are deprecating FTP mode.

I wanted more information than the FCC's AM Query could deliver. CDBS files document in detail the AM, FM, and TV (including digital) services, right down to measured signal strengths and distance between towers. Being an old programming hand for many years, some time ago the idea occurred to me to write a program which would use these files as input and provide a varied display of interesting and useful station data. My Radio Data MW program was born, and has become a sort of sideline hobby for me ever since. If I ever get it to a distributable state, I may one day publish it.

For the enthusiast or budding programmer wanting to extract information out of these files, where does he or she begin? Actually, once unzipped, all of these files are simple text files which can be opened in any text editor. My choice for a text editor in recent years has been Notepad++. It is an excellent freeware editor, useful not only for text files but also programming and scripting.

Okay, now that we have our text editor/viewer, how and where does one begin to gather information on mediumwave stations? From the CDBS database, here are the FCC files which must necessarily be examined. The pertinent information in each file is described. Be careful to note that these FCC files cover all services: AM, FM, and TV, including Traveler's Information Services.

The facility file, (facility.dat)
This is the key file for unlocking all the others. There is one record here for each facility (station). The facility ID number within each record will eventually lead you to the rest. Keep it handy.

Information found in this file:

* The station's facility ID
* The station's service community city, state, and country
* The station's call sign
* The station's frequency
* The station's current licensing status
* The station's digital status (IBOC or not)

The engineering index file, (am_eng_data.dat)
Multiple records usually exist for each facility. The application ID in each record points you to the station's antenna system record in am_ant_sys.dat. Keep this handy too.

Information found in this file:

* Cross reference back to facility ID
* The station's class (A, B, C, D, or unknown)
* The FCC application ID (an identifying number)

The application file, (application.dat)
This file contains a historical list of all applications filed by every station in the FCC database. It is a huge file, some 60MB.

Information found in this file:

* Cross reference back to facility ID
* The FCC application ID with cross reference to the more commonly known application resource number (BL-19990713DC)
* A secondary call sign reference (can be an old or new call sign)
* A secondary frequency reference (can be an old or new frequency)

The antenna system file, (am_ant_sys.dat)
Multiple records usually exist for each facility. An individual record exists for each service a station is authorized to use (Unlimited, Daytime, Nighttime, Critical Hours), and multiples of these may even exist. In this file we get to the heart of the station's information.

Information found in this file:

* Cross reference back to application ID
* The station's antenna system ID
* Number of augmentations to the signal pattern
* Hours of operation (its service: Unlimited, Daytime, Nighttime, Critical Hours)
* The station's latitude (tower site coordinates)
* The station's longitude (tower site coordinates)
* The station's power for this service
* RMS signal strengths at 1 kilometer in three varieties
* The station's domestic licensing status
* Number of towers
* Antenna mode (DA2, ND1, etc.)
* Indicator showing if record is current or archived (important)

With a station's latitude and longitude, using proper programming it is possible to calculate its distance and bearing from your home location. It is also possible to calculate the sunrise and sunset times at the distant transmitter. Using the station power and/or measured signal strengths at 1 kilometer, and knowing the distance you are from the transmitter, the path loss and a rough relative received signal strength can be calculated for daytime reception of stations within a few hundred miles of your home location. Of course nighttime, with its enhanced signal propagation and atmospheric conditions, would preclude any calculated value.

The towers file, (am_towers.dat)
In short, this file contains everything you need to calculate a station antenna's broadcast pattern. You can also plot tower positioning. A record exists for each tower in a station's tower array.

Information found in this file:

* Cross reference back to antenna system ID
* Antenna system resource number (ASRN - FAA number)
* Tower height, measured in various ways
* Top load switch (tower type: 0, 1, 2, 3, etc.)
* Signal field strengths
* Relative tower positioning
* Tower spacing
* Tower phasing

AM broadcast station signal pattern graphs are calculated through a rather complicated formula. A description of this and other formulas can be found at:

Directional Antenna Systems
Modification of directional antenna data

An excellent treatise on using these formulas can be found at:

A Modern Method Of Predicting AM Tower Vertical Radiation

The augmentations file, (am_augs.dat)
This file documents the augmentations to the station's signal pattern. Multiple records can exist for each facility if augmentations are used. Radio station signal patterns are sometimes further modified at the tower site by what are called "augmentations". Augmentations are modifications to the standard broadcast signal pattern, usually to further null the signal strength in a certain direction to bring it into FCC "signal contour" compliance.

Information found in this file:

* Cross reference back to antenna system ID
* Azimuth of augmentation
* Span (in degrees) of augmentation
* Radiation strength of augmentation

Using this information, we can further refine a generated graph of the station's signal pattern.

The facility index, (fac_party.dat)
This file is a simple cross reference of facility ID to owner information in the party.dat file.

Information found in this file:

* Cross reference back to facility ID
* Index forward to party ID (for owner information)

The owner information file, (party.dat)
A huge file of all kinds of owner information.

Information found in this file:

* Owner names and addresses indexed by party ID

And finally, to decode what all the above files mean, be sure to examine:

Code Table
Engineering Data Description (PDF)


Counting Licensed Stations

Have you ever seen the official FCC licensed station count? Lately the count has been 4786. The FCC uses the facility.dat file to determine this number. In this file, each facility has one line of information. There is a field in each line indicating the station's licensing status. Simply by totaling the number of LICEN (licensed) and LICSL (licensed but silent) entries gives you the licensed count. Total the LICSL entries by themselves, and you have a count of the number of licensed but silent stations.

Counting Digital (IBOC) Stations

Again, the the facility.dat file is used. A single character field in each record contains the letter "H" or "D" if a station is digital. Currently no "D", or purely digital mediumwave stations exist, they are all hybrid ("H") IBOC. Non-digital stations show a blank field. Count the number of "H"s, and you have the IBOC count.

Gathering It All

Combine the facility.dat file information with the engineering data index file information (am_eng_data.dat) and you know the station's class and most recent application ID. Look for this application ID in the antenna system file (am_ant_sys.dat) and you will have the station's position coordinates, hours of operation, and a host of other information. Cross reference the facility ID to the party.dat file and find the owner information. And finally, inspect the am_towers.dat file using the station's antenna system ID for the detailed field strength and tower information. Use the tower information and theoretical field strengths to calculate the antenna broadcast pattern.

Simple, it is not. It is overwhelming at first. The FCC's file layout is not friendly. But a tremendous wealth of information is available to the enthusiast or programmer who wants to work at it.


The FCC database has information on Mexican stations. Use it with caution. The two neighbor countries on our borders, Mexico and Canada, must file with the FCC for every station that wishes to broadcast. We do the same for them. Much of the data within is hopelessly outdated, especially the data for Canada, as Canada continually loses many of its mediumwave stations to the FM service.

The published link for official Mexican government mediumwave data is:


It is a PDF document of all supposed currently licensed and on the air mediumwave stations. All I have ever been able to get out of this link is a "503 - Service Temporarily Unavailable" response.

The next best bet comes from the official Mexican telecommunications site, Cofetel. The only government list I have found available, also in PDF form, is the Infraestructura de Estaciones de Radio AM list. Though the URL address is dated 2008, the actual PDF retrieved is dated 31-Dic-2009, or December 31, 2009, so hopefully the information is somewhat current.

Unfortunately, this station information lacks transmitter latitude and longitude coordinates, and a host of other needed technical information. It might be possible to correlate the Mexican stations with the FCC's database to get this. I haven't put forth the effort yet.


Canada has a search page of its own for broadcasting databases, but like the FCC's AM Query, the entire story is not told and much technical information is left out. But we are in luck. It turns out that Canada has a set of files that will fill the bill for all technical information.

The Industry Canada engineering database houses it, with link shown just below.

Industry Canada engineering database (

Rather than simple text files, Canada has chosen a dBase file format (.DBF) for its files. Download and unzip and you will have them. Though the records are somewhat textual in nature, they are more like XCEL records and a text editor cannot be used to view them. You must use a specialized viewer in order to look inside.

CDBF for Windows by WhiteTown Software, which used to be available as a shareware DBF viewer/editor/converter, seems now to be purchase only. A demo is available but usable only for a short time. A better choice now is Exportizer, totally free. It also supports conversion of the DBF file to other formats.

Once again we have our text editor/viewer, how and where does one gather information on Canadian mediumwave stations? From the Industry Canada database files, here are the ones which should be examined.

Information found in this file:

General AM station data, like the FCC's facility.dat file.

Information found in this file:

Tower info, like the FCC's am_ant_sys.dat and am_towers.dat files.

Information found in this file:

Description of codes used.

Information found in this file:

Country codes

Information found in this file:

Owner information

Information found in this file:

Signal pattern augmentations, like the FCC's am_augs.dat file.


Combining the Industry Canada information with the FCC's, we now have two countries with a wealth of information about their mediumwave service. If the missing information from Mexico's PDF file can be extracted from the FCC's database (namely the latitude and longitude coordinates of the stations), we can then create a single, comprehensive file with all the station data we need.

See also: Canadian/Mexican AM Station Search

Another country of interest but outside the North American realm is Australia. Under a separate post, Australian Mediumwave Database, I show where to find detailed technical information on Australian mediumwave stations.

The current build of Radio Data MW.

Friday, August 13, 2010

Mediumwave Oddities - Transmitter Power

We've talked about geographical mediumwave oddities for the United States, let's shift the discussion to transmitter power. Again, we will use data from current FCC records, this time from August 7, 2010. There are 4784 licensed stations in this survey. I have found 4787 licensed stations in the database, one more than the 4786 total the FCC publishes. I am excluding WR2XJR-670, Portsmouth, Virginia, a questionable FCC record for a synchronous station, and WWWS-1400 and WWGP-1050, both of which are reported licensed and on the air, but have no current antenna engineering record in the FCC database.

Daytime and nighttime data differ, so I will try to be explicit on the figures presented.


As you probably already know, 50,000 watts (50KW) is the maximum power allowed for a US mediumwave station. All 50KW stations used to be Class A clear channel stations, but that is no longer the case. 50KW stations can be Class A, Class B, or Class D, depending on the area they serve.


First of all, how many total stations are on the air during daytime hours?

All 4784 FCC-licensed stations can operate during daytime hours.

How many 50KW stations are there?

Throughout the FCC dragnet, there are 245 stations transmitting at 50,000 watts during daytime hours. 324 stations are transmitting at 20,000 watts or higher. 600 stations at 10,000 watts or higher. The vast majority, 4184 stations, transmit at a power under 10,000 watts.

Here's some figures for other power levels:

10,000 watters - 331
5,000 watters - 1172
1,000 watters - 1819
500 watters - 271

717 stations transmit with a power less than 1,000 watts during daytime hours.

Which station transmits with the lowest daytime power?

Lowly WBCP-1580, Urbana, Illinois with 135 watts. Only 10 stations total transmit with less than 200 watts.

What is the total power output of all stations combined?

A whopping 27,323,022 daytime watts! (27,323.022 kilowatts)

Currently, power companies in the US charge anywhere from about 8 cents per kilowatt hour to about 20 (Hawaii has the highest rate at 27 cents).

Considering 15 cents per kilowatt hour an average rate, how much does it cost to run all of these transmitters for one hour?

27,323.022 kilowatts per hour costs $4,098 each hour to operate. Over a 12 hour daytime period, the grand total paid to the power companies is an astounding $49,181, essentially 50 thousand dollars per half day in power costs alone.


How many total stations are on the air during nighttime hours?

4178 stations can operate during nighttime hours, out of 4784 stations total. This leaves 606 stations which are licensed for daytime only operations.

How many 50,000 watt stations are authorized to transmit at this power level at night?

97 stations are at the 50KW level during nighttime hours, versus 245 during the daytime. 122 stations are transmitting at 20,000 watts or higher (versus 324). 212 stations at 10,000 watts or higher (versus 600). 3966 stations transmit at a power under 10,000 watts.

Here are the other figures for nighttime hours:

10,000 watters - 78 (versus 331)
5,000 watters - 408 (versus 1172)
1,000 watters - 1360 (versus 1819)
500 watters - 250 (versus 271)

2031 stations transmit with a power less than 1,000 watts during nighttime hours.

Under 1,000 watts, things start to get really interesting, as nighttime operations are a totally different ballgame than daytime due to greatly enhanced signal propagation. Many, many low powered stations abound.

Which station transmits with the lowest nighttime power?

We have a tie. 14 stations transmit with a flea-power signal of only one watt! In fact, 120 stations are on the air transmitting with less than 10 watts! Between 1 and 99 watts, there is at least one station transmitting at each unit of power level, i.e., at 1,2,3,4,5,6,7,8,9,10,11,12,13....47,48,49....all the way to 99 watts.

There are 1028 stations transmitting less than 100 watts at night. Of those, 908 are at power levels between 10 and 99 watts. Between 100 and 500 watts, we have 551 stations.

So, the record holders at 1 watt output level are these 14 stations:

WNBL-1540, Booneville, IN
WRFM-990, Muncie, IN
WGAB-1180, Newburgh, IN
KBOA-1540, Kennett, MO
WZRK-1550, Lake Geneva, WI
WJJT-1540, Jellico, TN
KLKC-1540, Parsons, KS
WSRY-1550, Elkton, MD
WSQR-1180, Sycamore, IL
KDYN-1540,Ozark, AR
KLEY-1130,Wellington, KS
WCKB-780, Dunn, NC
WPGR-1510, Monroeville, PA
WHFB-1060, Benton Harbor, MI

Of these, Indiana is the clear winner with 3 of the lowest powered stations in the US.

What is the total power output of all nighttime stations combined?

10,856,121 nighttime watts (10,856.121 kilowatts). This is opposed to the daytime total wattage output of 27,323,022 watts. The nighttime power level is about 40% of the daytime level. One hour of nighttime electricity costs the radio stations $1,628. Twelve hours of operation at night costs $19,541.

So, the total cost of mediumwave broadcast transmitter power in the US, operating 24 hours per day, comes to approximately $68,722, based on a 15 cents per kilowatt hour charge by the power companies!

How many of you mediumwave DXers have heard these flea power stations, under 10 watts? Maybe we should have a certificate award for receiving a prescribed number of flea powered stations, perhaps under 100 watts, or even under 10 watts?

Coming up next: Mediumwave Oddities - Towers

More power to you, mediumwave DXer!

Saturday, July 31, 2010

Mediumwave Oddities - Geography

Think you know mediumwave? Are you good at geography? Do you like statistics?

Let's look at the geographical oddities of the mediumwave band for the United States. Information has been gleaned from current FCC records, and includes only US-licensed stations. 4784 licensed stations were used to compile these statistics from the FCC database dated July 14, 2010.


Did you know that 21% of all US-licensed AM stations are east of Florida? This one surprised me.

Which US station is the farthest east? Remember, east goes all the way to the International Date Line.

If you guessed a station in Maine, you would be wrong by a great margin. The farthest US station in the eastern hemisphere is KCNM-1080 (5KW), Saipan, Northern Marianas at 145.714E longitude. Next would be KGUM-567 (10KW), in Agana, Guam at 144.759E longitude. Three other stations in Guam are #3, #4, and #5 farthest east in longitude, west of the International Date Line.

So, how about the continental US? Are we there yet?

Think Carribbean. WSTX-970 (5KW), in Christiansted, US Virgin Islands is next farthest east at 64.693W longitude, and the most eastern US station in the western hemisphere. Five other US Virgin Islands stations are next.

Next comes a slew of stations in Puerto Rico, in fact 75 of them. The farthest east in Puerto Rico is WMDD-1480 (5KW), at 65.64W longitude.

Now we finally come to the continental US. The most easterly station in the continental US is WXME-780 (5KW), Monticello, Maine at 67.817W longitude. However, there is an application on file for a "NEW" AM station in Calais, Maine at 67.266W longitude which will take the title if it ever goes on the air.

But what about Florida, you ask?

Florida is not even close in the running. WWRF-1380 (1KW), Lake Worth, Florida at 80.072W longitude is the station farthest east in Florida. Astonishingly, there are 921 stations up and down the east coast of the continental US which are farther east than Florida's WWRF-1380, and 1007 stations farther east in total, clear to the International Date Line, all licensed to the US via the FCC.

Amazingly, 1007 stations (21%) of 4784 licensed FCC stations are east of Florida.

Which is the most easterly NPR (National Public Radio) station?

WFPB-1170 (1KW) Orleans, Massachusetts at 70.01W longitude.

Most of us know that "K" stations are west of the Mississippi, and "W" stations are east of the Mississippi, except for a few exceptions, like KDKA-1020 in Pittsburgh, PA and KYW-1060 in Philadelphia, PA and WOAI-1200 in San Antonio, Texas.

Which is the farthest east "K" station, east of the Mississippi River?

That would be KCNM-1080 (5KW), Saipan, Northern Marianas at 145.714E longitude. It is 7788 miles east of Wasington, DC where the FCC is located, and most definitely east of the Mississippi River. The most easterly "K" station in the lower 48 states is KYW-1060 (50KW), Philadelphia, Pennsylvania at 75.248W longitude.


Which US station is the farthest west?

We have two winners. KJAL-585 (5KW) Tafuna, American Samoa at 170.776W longitude and WVUV-648 (10KW), Leone, American Samoa at 170.776W longitude, both in the South Pacific and licensed by the FCC, some 7035 miles west of Washington, DC. They transmit from the same location.

Which is the most westerly station in the lower 48 states?

KBIS-1490 (1KW), Forks, Washington at 124.388W longitude. There are 72 stations farther west of this, all in Alaska or the Pacific Ocean.

Which has more AM stations, Hawaii or Alaska?

Hawaii has 30; Alaska has 40. Alaska is the winner.

Which is the most westerly Alaskan station?

KICY-850 (50KW), Nome, Alaska at 165.314W longitude. There are a total of 6 Alaskan stations that are farther west than the most westerly Hawaiian station, KUAI-720 (5KW), on the island of Kuai.

Which is the most westerly NPR station?

KOTZ-720 (10KW), Kotzebue, Alaska at 162.568W longitude.

Which is the farthest west "W" station, west of the Mississippi River?

The prize goes to WVUV-648 (10KW), Leone, American Samoa at 170.776W longitude. So much for WOAI-1200 in San Antonio, Texas! WOAI-1200 is the most westerly in the lower 48 states.


Which US station is the farthest north?

KBRW-680 (10KW), Barrow, Alaska at 71.256N latitude.

Which NPR station is the farthest north?

Again, KBRW-680 (10KW), Barrow, Alaska at 71.256N latitude.

How about the continental US? Which station is the farthest north?

We have a tie. KVRI-1600 (50KW), Blaine, Washington at 48.954N latitude and KARI-550 (5KW), Blaine, Washington at 48.954N latitude.

How come a station in Maine isn't the farthest north?

The most northern station in Maine is WFST-600 (5KW), Caribou, Maine at 46.886N latitude. 180 stations are farther north than WFST-600, and all are scattered from Minnesota all the way to Alaska.

The geographical center of the lower 48 states lies outside of Lebanon, Kansas, in the middle of what used to be a hog farm.

Are there more stations to the north or to the south of this location?

There are 1814 stations to the north and 2970 stations to the south of Lebanon, Kansas.


Which US station is the farthest south? Think outside of the continental US.

Another tie. KJAL-585 (5KW) Tafuna, American Samoa at 14.357S latitude and WVUV-648 (10KW), Leone, American Samoa at 14.357S latitude. Coincidentally, these two stations are not only the farthest south, but also the farthest west.

Which is the most southerly station in the continental US?

WKIZ-1500 (250W), Key West, Florida at 24.567N latitude. The Florida Keys have 3 stations - 2 in Key West, and 1 in Marathon Key.

How about Texas? It's pretty far south.

The most southerly station in Texas is KVNS-1700 (8.8KW), Brownsville, Texas at 25.949N latitude.

And California?

That would be KURS-1040 (360W), San Diego, California at 32.694N latitude. Texas is much farther south than California.

How many stations are south of the continental US?

There are 118 stations south of the continental US, that is, south of Key West, Florida. All are in the Pacific or Caribbean.

The Mississippi River runs north and south through the country, dividing the US east to west approximately at St. Louis, Missouri (90.18W longitude).

Are there more stations to the east or to the west of St. Louis?

There are 1990 stations west of St. Louis and 2794 stations east of St. Louis. The majority of stations are to the east of St. Louis, in fact, 71% of them.


How about some IBOC stats?

There are 293 licensed IBOC stations. Two are silent at the moment.

The most westerly IBOC station is KOTZ-720 (10KW), Kotzebue, Alaska at 162.568W longitude. It is also the most northerly IBOC station and the most westerly NPR station.

The most easterly IBOC station is WIPR-940 (10KW), San Juan, Puerto Rico at 66.141W longitude. It is also the most southerly IBOC station.

There are 128 IBOC stations west of the Mississippi River. There are 165 IBOC stations east of the Mississippi River.

Which state has the most IBOC stations?

California wins with 32. Runner up is Florida with 25, followed by Colorado at 17. New York has 16, and both Texas and Ohio have 15 each.

Which state has the fewest IBOC stations?

Several are tied. Kentucky, Mississippi, North Dakota, Nebraska, and South Carolina have 1 each. Arkansas, Delaware, Idaho, Louisiana, Maine, Montana, New Mexico, and Nevada have 2 each.

Which state has the most IBOC NPR stations?

Surprise! Alaska wins with 6. Alaska also has the most NPR stations overall at 9.


How many "K" call signs?


How many "W" call signs?

2877. The "W"s win by a huge margin.

We have a KAAA and a KZZZ, but no WAAA or WZZZ.

What are the oddest call signs?

Puerto Rico gets the win here. WA2XPA-680, WI2XAC-740, WI2XSO-1260, and WI3XSP-1260. These four are experimental synchronous stations. Usually AM synchronous station call signs are named the same as the host station, like KKOB-770 in Albuquerque, New Mexico, which runs one in Santa Fe, also KKOB.

Which state has the most stations?

Texas takes the prize with 298, then California with 250.

Surely New York is next, right?

No. New York is #8 ranked with 168. Florida (227), North Carolina (219), Tennessee (185), Georgia (183), and Pennsylvania (180) all have more stations than New York (168). Weirdly, New York ranks just above Alabama, which has 152.

Which state has the fewest stations?

That would be Delaware with 10, followed by Rhode Island with 15 and Vermont with 19.

Coming up next: Mediumwave Oddities - Transmitter Power


Station powers listed are for their daytime service. Nighttime powers may be lower in some cases.

Sunday, July 25, 2010

Digital Radio Update

Let's take a look at the current state of the digital radio conversion process in a few selected countries around the world.


Almost a year has passed since I reported on The IBOC MESS In North America. Since then, hybrid-digital IBOC conversions (HD Radio) on the US mediumwave AM broadcast band have come to a near dead stop. There seems to be little excitement for new stations to jump on the Ibiquity AM bandwagon, what with a scattered amount of dedicated equipment available and marginal listener interest, not withstanding the large cash outlay stations need to get signed up and converted. Available receiving equipment seems to be a few clock radios, some home sound system type tuners, and car radios (which seem to be coming on strong). Portables have largely been ignored. Sangean had plans to make an intriguing little AM/FM model, the DT-600HD, however the AM band on this unit was to be traditionally analog. They dropped the product before it got to the marketplace.

Last year at August 27, 2009, we had 289 licensed IBOC AM outlets, per FCC files. As of this writing we have 293, and two of them are silent. This is a net gain of only four new registrations in the last 11 months. In the past year there have been reports of several stations switching off their digital signal due either to problems, interference complaints, or lack of interest, so the actual count of stations currently transmitting IBOC is almost certainly under 290. Using the figure 293 against the total number of licensed AM broadcast stations in the US (4786), the AM IBOC factor is 6.1%. At this rate, AM IBOC cannot sustain itself.

Then, there is the adjacent channel interference problem, particularly bad at night, which many still complain about. And rightfully so. Nightly, digital broadband hash continues here in the northeast and other parts of the country on the mediumwave band. Earlier this year, one evening after dark I was driving through Phoenix, Arizona trying to listen to local AM station KMVP (itself an IBOC station) on 860 KHz. It transmits at 1KW. Every time adjacent channel KOA-850 (another IBOC, at 50KW) out of Denver, Colorado peaked, KMVP was not receivable due to the digital hash. It was maddening.

Earlier this year, Ibiquity announced  2010 fire sale pricing (good through December 31) for new stations wishing to join the digital "revolution", with the stipulation that they be "stations eligible for discount pricing", whatever that means. The existing $25,000 main channel licensing fee was reduced to a remarkable figure of $10,500 if payment is made up front. Monthly payment plans (at an overall higher total figure) for those stations less able to scare up this kind of money all at once were also instituted. It seems that the original higher flow of incoming cash might be slowing down. Ibiquity claims that one new digital station goes on the air on the average of every four days. I guess this must mean FM, as the AM figures don't support this claim. It will be interesting to see if the fire sale continues into next year.

So what is the current market share for HD Radio in the US? A 7 month old Bridge Report hinted at it.

12/15/2009 Bridge Ratings: New Media's Effect On Radio Lessening

"HD Radio, though it reaches only about 650,000 people, is attracting 'considerable listening time' of about 11.5 hours a week", though Bridge says "that's down from previous surveys, attributing the change to a larger number of HD receiver owners, diluting the impact of the heavy users."

"Respondents were also asked what audio devices they use every day, with a choice of AM/FM radio, HD Radio, cellphone, satellite radio, and Internet radio. Nearly 90 percent of radio listeners also use a cellphone every day, while more than 44 percent use an MP3 player. About 35 percent listen to Internet radio every day, with satellite radio and HD Radio well behind."

6/30/2010 Bridge Ratings: Is Terrestrial Radio Ready for a Digital Future?

Things are not moving along very quickly. Back to mediumwave, we can only hope that Ibiquity eventually gives up on the mediumwave band, or the government does, or both, and they take the AM patient off of life-support.

Beyond our borders, several other countries have issued mandates to go digital for some or all of their radio broadcasting services. Let's examine some of their stories.


4/14/2010 Mexico Is Set to Elect IBOC

Information out of Mexico is paltry, and I have seen nothing new since April. It would seem that this is a done deal, with Mexico on the verge of adopting IBOC as their standard. Back in May 2008, a 200 mile wide border zone was established along the US - Mexican border allowing Mexican AM and FM stations to use the IBOC format to "take decisive action so that the country’s AM and FM radio stations in the zone located within 320 km of the northern border of Mexico can transmit at the same technological level so that they can provide the benefits of quality service to the radio listening public."

Supposedly, there are two, or six, or nine IBOC outlets, depending on what you read, and at least two more deeper down in Mexico itself in or around Mexico City (XHDL and XEDA). The two call signs I have seen reported along the US border are AM outlet XEEZ 970 Radio Palacios from Caborca, Sonora, and the other, an FM outlet, XHTY-FM 94.5 in Tijuana. The station news is all old news anyway and reported a long time ago, way back in June 2008. I have heard no other IBOC-rollout fanfare since then.

Suddenly in early 2009 Mexico announced that it intended to convert all AM radio station outlets to FM, country-wide, a wholesale disbanding the AM service. They even published a schedule of the conversion dates, to take place between August of 2009 and August of 2010 (see page 8).

Whether this eventually happens or not is anyone's guess, but you can bet on it not happening by next month. Local reports out of Mexico indicate that some regional areas have abandoned the AM mode, particularly in the southeast. The government's general idea, I think, was to force the big city AM outlets to convert to FM (and in the future, IBOC), and let the rural outlets languish and eventually disappear. However there was no lack of border blasters in southwestern Arizona, where I spent last winter. The Nogales to Tijuana border strip has a sizable number of AM outlets, but none running IBOC as far as I can remember hearing. Assuming I get to Arizona again this winter, I will pay more careful attention to what is coming out of Mexico. Needless to say, the AM to FM conversion in Mexico is coming along slowly. And IBOC even slower. So where does this leave Mexican AM IBOC?

Curiously, Mexico's announcement of being on the brink of voting to adopt the IBOC methodology is some months old now, with no action since. It seems they can't pull the trigger. Maybe they realize that it's just a whole lot of money and effort for no good end, at least on the AM side. Or maybe they are dragging their feet waiting to see what happens with IBOC in this country. IBOC may be on life-support for the mediumwave band in the US, but FM has greater presence. As of this writing, 1569 stations (8 not on the air) are shown with IBOC permits in the FM service. This is compared to a total of 9608 full-fledged FM stations on the air, commercial and non-commercial, 130 of them showing silent at the moment. Using the figure 1569 against the total number of licensed FM broadcast stations (9608), the FM IBOC factor is 16.3%. Still not a great showing. However, listenership seems to be coming around.

May 2010 FM HD Radio is Becoming a Fact of Life for American Radio (be careful with this news, it is an Ibiquity article)


Canada (having wanted to go with the DAB standard) seems to be stalled on the whole digital radio broadcasting question, according to a recent article this month in Radio Magazine Online. The article reports that "government observers agree that the service has reached the end of the line....with DAB's imminent demise, increased demand for analog FM frequencies is taking place in Canada's urban areas."

IBOC, where for art thou?

"While posts in online Canadian radio forums suggest a preference for HD Radio among hobbyists, government regulators and industry representatives still treat the the option with caution. Canada's Communications Research Centre, a governmental research body with an advisory role on telecom policy, has developed its own coverage analysis tool dubbed COVLAB to evaluate digital radio coverage and spectral compatibility, rather than simply deferring to U.S. data. IBOC digital radio testing has been conducted in Canada since 2006, and the Canadian government has said that it will accept experimental HD Radio digital hybrid applications from licensed FM stations, though few stations have stepped up to do so."

"So industry opinion on IBOC's potential in Canada is checkered at best. With many stations moving away from AM altogether, and interference concerns among those who remain, AM HD Radio is probably a nonstarter."

Exactly what I've been talking about. Canadian reader Greg writes:

"DAB failed in Canada because there was almost no public awareness of it and virtually no receivers on the market that could receive it. I never saw anyone selling or even advertising DAB receivers, and never even heard any mention of the service anywhere except on radio hobbyist sites and mailing lists. Canada's DAB system was a bit different than that adopted in the U.K., operating on a different frequency band. I wonder if it would have been more successful had we adopted the British standard, which would have enabled us to use receivers designed for the U.K.?"

7/7/2010 Canada DAB Shut Down

Outside of North America, at least four more countries are either entertaining or have adopted Digital Audio Broadcasting (DAB) or Digital Radio Mondiale (DRM) schemes. Europe and many parts of Asia have gone or are going with the DAB or DRM schemes.

Also see:

Digital Radio Mondiale Home Page
Country Information for DAB, DAB+ and DMB


Britain is an interesting story, in and of itself. The government is going gangbusters for DAB "Digital Britain" via the Digital Economy Act, and pushing it as hard as they can. However, the public and the pundits are panning it for now as "not ready", if ever. The government stipulates that the 2015 switchover "will go ahead only if 50 per cent of radio listening is via 'digital platforms' by 2013." Many say that will never happen by that soon a date, and that the switchover should be delayed for a period of ten years or more. At the forefront is the BBC. The BBC's digital radio stations now cover 86 per cent of the country (signal pattern coverage). The corporation has built 50 transmitters in the last year and plans 60 more in the next year to increase coverage to 90 per cent. Of course, nationwide, the thrust is mostly FM.

Whether their switchover happens by 2015 is the guess of the decade. Figures published showed that the audience share for digital radio in Britain – including listeners on digital TV and the internet – is rising at a record rate, up to 24 per cent from 20.9 per cent in the previous quarter (first quarter, 2010).

We shall see, if we all live long enough. No IBOC for Britain.

There is lots of interesting digital conversion news out of Britain:

7/22/2010 More On The Digital Economy Act

7/8/2010 Digital Radio Speech by the Culture Minister, Ed Vaizey

7/8/2010 Relax. Digital radio switchover will now never happen

5/23/2010 Digital radio switchover gets poor reception

4/8/2010 Say goodbye to your transistor radio, digital switchover is coming

9/9/2009 Britain Mulls Over Digital Radio Transition

6/16/2009 Digital Britain: Analogue radio switch-off set for 2015


India is going with DRM, and All India Radio has just ordered a fair amount of equipment. All India Radio is also big into shortwave, much of it used for national regional service. On mediumwave, transmitters there tend to be big boys - 100KW, 200KW, and 300KW to extend the coverage area. On the books are 34 new MW transmitters, upgrades to 36 existing MW transmitters and the purchase of 5 SW transmitters and other associated equipment. Interesting, I see no mention of FM in here.

7/1/2010 All India Radio tender notice for DRM digital transmitters

4/10/2010 Indian government approves country’s digitalisation plan using DRM


Australia has gone with the DAB+ method, a variation of DAB. All commercial and public service broadcasters are now broadcasting digital radio in Sydney, Melbourne, Brisbane, Perth and Adelaide. Australian commercial digital radio services switched-on progressively in May and June 2009 in the five state capital metropolitian areas. The public service broadcasters switched on 1 July 2009. A recent report revealed, "....the industry recently released figures indicating there were already nearly 500,000 people listening to digital radio across those markets."

"There are no plans at this stage to switch off AM and FM radio services", the report said. It continued on, "As there is an estimated five radio devices per home, listeners must be given time to change over all of their radios before any discussion of the switch off of analogue services. In addition, planning needs to continue for the switch on of digital services to the rest of Australia outside of the five metropolitan capital cities."

"It is expected that it will be some years before digital radio is extended to the bulk of the Australian continent. Australia's vast distances and low population density are not well suited to the propagation characteristics of DAB+ and it is therefore likely that a standard other than DAB+ will be adopted for serving areas outside the major cities."

At the moment, it looks like IBOC has lost out here. Australia may use DRM to fill in the nether regions if DAB+ doesn't work out.

Digital Radio In Australia (Wiki)

Digital Radio FAQs For Australia

7/19/2010 ABC Radio Is Now Digital (including AM outlets)

5/5/2010 Digital radio trial to begin in Canberra

8/13/2009 Rollout Of Digital Radio In Australia (announced in 2007)


Brazil is huge. Ibiquity has done IBOC testing here, and the HD Radio system has been used on a trial basis by a number of commercial broadcasters since 2005. Brazil is the second-largest radio country in the world in terms of station count, behind the United States. Brazil has more than 3,000 commercial stations and about an equal number of low-power community radio stations. This would be huge profit for Ibiquity.

"Brazil's target date for full roll-out of an IBOC approach to digital radio is the year 2016. The Congress of the Brazilian Association of Radio and Television Broadcasters is expected to make a standards announcement by the end of this year or in early 2011. However, there is also interest in Digital Radio Mondiale's DRM30 and DRM+ technologies. The possibility exists that the country will adopt different standards for AM, FM and shortwave."

"While AM and tropical-band shortwave remain important in large swaths of Brazil, DRM may be better positioned than Ibiquity's HD Radio AM for these wavebands, according to anecdotal comments on Brazilian digital radio message boards, blogs and press accounts. Yet HD Radio has more receivers on the market than does DRM. If regulators opt for DRM on AM and for HD Radio on FM, there is a concern that the rollout could be delayed by the manufacturing time necessary to produce dual-standard receivers, according to these accounts. Ibiquity publicly has supported the use of DRM30 for shortwave services in Brazil. It also supports the concept of multi-system tuners capable of receiving both HD Radio on AM/FM and DRM on shortwave."

IBOC is at the doorstep here, but not through the door yet. Again, like Australia, the rural regions may need to adopt the DRM technique for the AM service. We will soon see what Brazil decides.

5/27/2010 Brazilian Broadcasters make public open letter in support of DRM

5/12/2010 Brazil Could Pick Digital Standard in 2010


According to the Ibiquity web site, there are a handful of other countries testing and evaluating IBOC digital radio as of this writing. They are: Argentina, Austria, Canada, Chile, France, Hong Kong, Indonesia, New Zealand, Nigeria, Phillippines, Poland, Switzerland, Thailand, and Ukraine.

Ibiquity International