DXing The Edge

Out at the edges of the mediumwave broadcast band here in the western hemisphere - that would be 530 KHz and 1700 KHz - channels are thinly populated. US stations don't operate at all on 530 KHz. Here you will find only a few Canadians, a single Cuban, and a small handful of others. At the other end - at 1700 KHz - in the area called the X-Band (1620 KHz - 1710 KHz), the US is sparsely populated at best by only a half-dozen or so stations per channel. These stations generally run 10KW during daylight hours and only 1 kilowatt at night. The relatively low power and far-spaced distances make for some very interesting nighttime DX possibiltities, "sans interference". Let us continue....

The following station lists have been garnered from the FCC lists, the latest (2009) World Radio TV Handbook, and the Internet.

530 KHz

CKHL High Level, Alberta, Canada 1KW/400W (defunct)
CIAO Brampton, Ontario, Canada 1KW/250W
CJFT Fort Erie, Ontario, Canada 250W (defunct)
CIRS Sault Ste Marie, Ontario, Canada 50W (tourist information)
TIRI R. Sinfonola, Cartago, Costa Rica 10KW
R. Enciclopedia, Havana, Cuba 10KW
R. Vision Cristiana International, S. Caicos (Turks & Caicos) 40KW
La Voz de las Madres, Capital Federal, Argentina (power unknown)
R. Republica, San Justo, Argentina 5KW/1KW
HCDC1 530 AM (Radio Iris?), Quito, Ecuador 1KW
FIRS, Stanley, Falkland Islands 15KW

1700 KHz

KBGG Des Moines, IA 10KW/1KW
WEUP Huntsville, AL 10KW/1KW
KVNS Brownsville, TX 8.8KW/880W
KKLF Richardson, TX 10KW/1KW
XEPE (XEKTT) San Diego 1700, Tecate, Baja California Norte, Mexico 10 KW
R. Eternidad, Santo Domingo, Dominican Republic 5KW/1KW (daily, 6AM-7PM, per web site)
R. City (possibly inactive), Partido de Almirante Brown, Argentina
Radio Cristiana Príncipe con Dios, Villa Fiorito, Argentina

1710 KHz

AM 1710, R. Estudio ESBA, Capital Federal, Argentina
OBU4R R. Nuevo Tiempo, Huancayo, Peru


So back to the DXing. Two nights ago I couldn't sleep. I found myself wide awake at 3AM. In the middle of the night I fired up the Tecsun PL-600 receiver and parked it on 1700 KHz and waited. Conditions were good. The Kp-index was at 0 or 1, very low. In one hour I had logged three stations and a possible fourth.

Loggings for Sep 26, 2009:

1700 KHz, 0715 UTC, KBGG, Des Moines, IA. 1KW 814 miles. ESPN, sports talk. Local Des Moines ads.
1700 KHz, 0732 UTC, KVNS, Brownsville, TX. 880W 1621 miles. Positive ID at the 30 minute news break.
1700 KHz, 0750 UTC, WEUP, Huntsville, AL. 1KW 741 miles. Positive ID.

And a possible fourth?
1700 KHz, 0755 UTC, KKLF, Richardson, TX. 1KW 1227 miles. Ads for the Richardson/Dallas area.

In between, I tried a couple of other frequencies:

1600 KHz, 0738 UTC, WAAM, Ann Arbor, MI. 5KW 309 miles.
1710 KHz, 0745 UTC, ????, Spanish music. Weak, and in and out of the noise.

What's this? Oh, now this is interesting. The only stations documented to be on 1710 KHz are in South America - Argentina and Peru. Could it be?


The next morning, September 27, on my way to the coffee shop at 6AM I turn on the truck radio. Fading up out of the noise between 5:55AM and 6:05AM is some nice Spanish music. No ID at the top of hour, though. For fleeting seconds, here and there, it fades in, weak, but readable. Remember what I said about the greyline in a previous post? I check the greyline map for this time frame sometime later in the day. Perfect conditions - a nice greyline path to Argentina and Peru at 6AM! Perhaps one of these was the station I heard? I will keep trying.


R. Enciclopedia, Havana, Cuba, still eludes me on 530 KHz. I hear Spanish on this frequency occasionally, but no positive ID yet. CIAO, Brampton, Ontario, Canada dominates as it is just across Lake Ontario from this location. And it will not totally null in the receiver, not in the evening or early morning. I am also hunting for XEPE San Diego 1700, a 10KW station I hear routinely when I am wintering in southwestern Arizona. One day it will make the trip all the way to New York.

DXing the edges of the mediumwave band can be fun. Give it a try.

Calculations For The MW DXer

Two calculations are imperative to the mediumwave DXer.

1. Sunrise/sunset time for the distant station.



Signal enhancement occurs during sunrise and sunset times, both at the home location and the distant location. Seasoned DXers know this. Knowing when to listen is all-important. But when is sunrise and sunset at the distant station? Latitude and longitude for the station must be known for the calculation. These are available from the FCC database in a previous post, and other locations on the web. Also, and obviously, you must know the time of year: day and month, since sunrise and sunset times change day by day.

2. Distance to the received station.



Sometimes more an interesting statistic than anything else, distance helps somewhat in judging how good the DX is, and makes for an interesting fact in the station log. Again, latitude and longitude for the station must be known for the calculation as well as your own latitude and longitude. So, how can we calculate these? Luckily, both can be had freely on the web.

Probably the most accurate sunrise/sunset calculation on the web is the one presented by NOAA, The National Oceanic And Atmospheric Administration:

NOAA Sunrise/Sunset Calculation

The FCC also has a sunrise/sunset calculator, since it is in the business of policing its radio stations on daylight, nighttime, and critical hours activities:

FCC Sunrise/Sunset Calculation

See NOAA again for a nice distance calculator:

NOAA Distance Calculator

If you get into field strength calculations (see my series on this), you need a distance calculator that also returns the bearing of one latitude-longitude to another. The FCC has a great one.

FCC Latitude-Longitude Distance Calculator

And another interesting distance calculator which has been out on the web for a long time, though spartan, by Chris Michels:

Chris Michels Distance Calculator

Distance can be calculated in statute miles, kilometers, or nautical miles.

Two factors weigh heavily in DXing MW stations: think "Greyline" and "Solar Kp-Index".



Solar Kp-index is an index of geomagnetic activity. Kp-indices of 5 or greater indicate storm-level geomagnetic activity, and geomagnetic storms are not good for great DXing. Geomagnetic storms have been associated with satellite surface charging and increased atmospheric drag. For good mediumwave propagation, think Kp-indices of 2 or less. 1 or 0 is even better, and you will hear the difference on your receiver on a good night. NOAA has a great site which predicts the solar Kp-index over the next three days:

NOAA Kp-Index 3-Day Forecast

It is also presented in graphical form here, a site I refer to often:

NOAA Kp-Index 3-Day Forecast (Graphic)

In the graphic, check out the time period on September 18 from 0600 - 1200 UTC. A very low Kp-index. Conditions were great. These data are made available through the cooperation of the Geological Survey of Canada (GSC) and the US Geological Survey.

More information can be had about the solar Kp-index here:

NOAA Solar Kp-Index Information



Now, how about that Greyline? The line that separates day and night is called the terminator. It is also referred to as the "grey line" and the "twilight zone." It is a fuzzy line due to our atmosphere bending sunlight, separating day and night, and usually lasts some 30 to 45 minutes after sunset or before sunrise. Stations or receivers at sunrise or sunset and in the terminator zone will exhibit enhanced propagation characteristics through the nighttime path. It's easy to know when we ourselves are in this zone, harder to know when the distant station is. Use the sunrise/sunset calculator to figure the sunrise/sunset times for the station of interest. Watch for the "pipeline effect". That is when both you and the distant station are in the greyline - you have continuous greyline between you. Signals can be greatly enhanced during these times.

To see where the realtime greyline is right now, check out these sites on the web:

Greyline#1 - www.fourmilab.ch
Greyline#2 - www.fourmilab.ch
Greyline#3 - www.die.net/earth
Greyline#4 - www.daylightmap.com

More information can be had about the greyline on the wikipedia.org web site.



And now for a program plug. DX Atlas, a program developed for amateur radio operators, has a wonderful mapping ability to display the current greyline for your location, or for any other time of year. This program by Alex Shovkoplyas, VE3NEA, is outstanding. It even has the ability to create ionospheric maps, useful for the shortwave spectrum. DX Atlas is shareware, and requires registration and purchase after 30 days.

A Brick No More

And the Eton E1 crisis has been resolved, at least so far. "gkinsman" responded to the previous post about my E1 problems and suggested a fix he saw in the Yahoo Eton E1 group. Something about a "stuck light switch". Well, after fiddling with the light switch on the E1, it suddenly sprang to life. And, it is working on battery power again, too. Seems to be stuck in Timer mode for the moment, but I think I can resolve that. A big "THANKS" to "gkinsman" for the tip!

I stick by my late comment, though, "This will be the last portable radio I spend $400 on". Too much money for a portable. But it's great having the E1 back in working order.

The $400 Brick

Someone once said that life is all about constantly "saying goodbye". Well, goodbye fair Eton E1. You were a great receiver while you lasted. Am I frustrated? You bet I'm frustrated.

Note: Problem resolved! See this post.

I hadn't turned this receiver on for about three weeks. Yesterday I thought I'd take it outside and check the WCBS AM signal strength out of New York City (265 miles), as Fall conditions here are dramatically improving and I heard this station on the anemic car radio at mid-day. Mistake. I should have left the E1 on the shelf and me in my innocent, ignorant bliss.

I turned the unit on. It came to life. Spun the tuning dial down to 880 KHz. Drat - splatter from local signal swamper WYSL. The usual. I hit the bandwidth button to switch down to a narrower bandwidth. What's this? The button is ineffective. What the....so are all the other buttons surrounding the display. I check the lock function to see if maybe the radio's controls somehow got locked. No. Not locked. Grim becomes grimmer.

Power off. Power on. Same thing. Reset the processor. Power on. Same thing. Check batteries. Batteries okay. I give up. I'll charge the batteries anyway, overnight, and try again in the morning.

Enter this morning. Batteries charged. Pop them into the radio. Hit the power button. Nothing. Not even the clock. Reset the processor. Nothing. I hunt for the A/C wall adapter. There it is. Plug it in. The display lights up. I have a clock. Perhaps? I press the power button. Nothing. Nothing. Nothing.

I will think about this for a day or two. Too bad, I was thinking about selling this radio because I rarely use it anymore. Now it is worthless. Get it fixed? I doubt it. It's out of warranty. It is just more than a year old. I'm not sure I even want it at this point.

This will be the last portable radio I spend $400 on. If I have $400 to burn again (unlikely), I will add another $200 to it and get a tabletop. Too bad, really. The E1 was every good a receiver as my old Drake SW-8 which is what it was designed after. The AM-sync was unmatched. Excellent sensitivity and selectivity. Passband tuning. Dynamite software control. Horrible display, though. Dark, like a cheap LCD weather station from K-Mart. And a reputation for display problems. Live and learn.

More on this another time if the E1 miraculously resuscitates itself. But I doubt it will. Maybe I'll open the case and have a look at the power button in a day or two. My $400 brick, and my last.

Three Helpful Web Sites For The MW DXer

Mediumwave DXers can be a pretty technical bunch. I know I am one in that crowd. I like to know "Why", "When", and "How". And mostly just "When, and is it Possible"? That is, in terms of receivable stations and the various possibilities thereof. Three web sites exist that can tell us some interesting technical things about the stations we want to receive.


Radio-Locator is probably the one I use the most. My favorite chunk of information available on this site are the antenna pattern/coverage maps. Type the call sign of the station you are interested in and up comes a page with a lot of information about the station. Click the coverage link on that page and see the predicted coverage drawn on a map. Stations with different day and night (and critical hours) antenna patterns have separate maps showing each coverage pattern. You can even click a latitude/longitude link which generates a Google map of the transmitter site.

Radio-Locator has three other great features for general station searching. A US state search allows you to search for stations by state. A format search allows you to search stations by format. A city/zipcode search allows you to locate stations by city or zipcode. There is also a Canadian station search page similar to the US state search. Radio-Locator also includes many Mexican stations in its database, searchable by call sign.


Next, V-Soft Communications owned by Doug Vernier, supplies software products for the communications world. Its important contribution to MW DXers is its Zip Code Signal pages. Type your zip code in the box and click the Find Stations button, and back comes a page listing all stations in your area with a signal strength of 50dBu or greater (display is in millivolts per meter - mV/m - for AM). Each station is linked so that a click on the station call sign takes you to the FCC page describing its facility - another wealth of information. Zip Code Signal also has a reverse look-up feature. Type the station call sign into another box, click the Find Zip Codes button, and a page is returned that shows all nearby zip codes where that station puts in a signal strength of 50dBu or greater (again, in mV/m for AM). Neat stuff.


Last, the FCC to the rescue. One of the most, if not THE most, comprehensive US station lists on the 'net comes from the US Federal Communications Commission. The FCC maintains a database of all US AM, FM, Travelers Information Stations (TIS), and many Canadian and Mexican stations. Information includes geographic coordinates of all transmitter sites, station power, owner, antenna type, and more. The FCC's AM Query web page will extract the information you desire from its official database records and present it in a readable format.

Give these three sites a look when you have a chance. I think you will find them as useful as I do.

The 42-Inch Passive Loop

The 12-Inch Passive Loop, constructed earlier, is great for its portability. It sits very nicely on a small garden table. Unfortunately, its signal gain is not much better than a tuned ferrite stick of moderate length. For the next project I considered building an 18-inch or 24-inch, but I rejected the idea outright - not a big enough improvement for the cost and effort to construct them. For real signal grabbing power, the loop size must be increased to 36 inches or more. 42 inches seemed like a good compromise between a 3 and 4 foot loop.

I prefer working with wood here, as I have a lot of scrap available and a nice table saw for cutting whatever size I want. How long to make the cross members, you ask? The formula is quite simple.


Multiply the side length of any loop by the square root of 2 (1.414). So, taking the side length of 42 x 1.414 we get a cross member length of 59.388 inches. I located a nice piece of 1/4 inch pine that was two inches wide, and cut two pieces 59 inches long. It is lightweight and strong enough to support the wires without bending. Each piece was notched halfway through at the middle and fitted together. Next I cut an 8 x 8 inch piece of 1/8 inch veneer and screwed it to the center to sturdy-up the cross and hold the members at right angles. No glue was used on this project at all.


A 42-inch loop is a fair-sized piece of hardware. How do we rotate it? It certainly won't sit on a garden table. I had a 36 inch piece of 1/4 inch steel rod lying about and the idea occurred to me that it might somehow be attached to the loop and pushed into the ground to serve as a pivot. I cut a 27 inch length of 1 x 2 furring strip and screwed it to the center support plate so that it bisected one of the sides. It extends about one inch past the coil edge. Carefully, I then drilled a 1/4 inch hole into the end of this furring strip, about three inches deep to accept my steel rod. As shown, the loop can now be pushed into soft soil and it will rotate freely.


Now to construct a mount for the tuning mechanism. On the 12-inch loop it hardly mattered and I mounted the variable capacitor through the center support plate. On a loop of this size, the tuning mechanism needs to be out at the end of one of the members where the loop ends terminate. I had some scrap 1/8 inch plexiglass, so I cut a small rectangular piece and mounted a 365 pf variable capacitor and an SO-239 coax receptacle through it. The SO-239 coax connector will be left unwired, to be used at a future time for the termination of a one-turn coupling coil. I then screwed the plexiglass to the edge of one of the two cross members nearest the rotating arm.


The 42-inch loop requires 9 turns of wire, 126 feet total. I had 100 feet of white, 20 gauge solid insulated wire, so to that I soldered a scrap of 20 gauge black wire that was lying around. This is why you see two different colors of wire in the photographs. Small wire nails hammered into the ends of the cross members serve as starting and ending pins for the coil. At the end of each of the four cross members I filed notches 3/16 inch apart to properly space the loop turns. When the coil was wound and secured, I then soldered the ends to the variable capacitor.

Signal strength on this loop is phenomenal, and exponentially better than the 12-inch loop. Nulling and peaking are both fairly sharp. The base tuning range of the loop is approximately 520 KHz to 1500 KHz, too narrow to cover the entire mediumwave band. A short jumper wire with clips at each end was fashioned to short-circuit one turn of the loop. This changes the tuning range to approximately 650 KHz to 1750 KHz. The loop couples well to my ultralights and the Tecsun PL-600, and often a radio only needs to be one or two feet away for improvement. Pushed into the ground and ready for rotation, the tuning panel is perfectly accessible from lawn chair height.

All-in-all, this has been a very worthwhile project. Though this sized loop would be cumbersome to carry in a small car, it performs very nicely in a backyard environment and can be stored flatly on a wall in the garage. Sometime in your DXing life try building one of these larger loops. You will be amazed at their performance.

Empires Of Light

Okay - not radio - but electricity, for without electricity we would not have our beloved radio. Here is what promises to be a great book which documents the race to see who would electrify the world first - Nikola Tesla, Thomas Edison, or George Westinghouse.

From Publisher's Weekly - Author Jill Jones "details the rise and fall of the three visionaries who harnessed electricity, while also offering a critique of corporate greed. Her tale emphasizes the "War of the Electric Currents," in which Thomas Edison sought to defend the primacy of his direct current electrical system against George Westinghouse's higher-voltage and more broadly applicable alternating current system. Nikola Tesla, the somewhat kooky Serbian genius (and former Edison man), joined the fray on Westinghouse's side with his AC induction motor."

I purchased this book from Borders last week. This one will be on the top of the reading stack for the Arizona trip this year.

See the Edward Morris review-

http://www.bookpage.com/0308bp/nonfiction/empires_of_light.html

The 4-Inch Tunable Ferrite Bar

This summer I've been searching the flea market for transistor radios and radios otherwise having ferrite loopstick rods or bars. The occasional portable or tabletop transistor radio is to be found, sometimes at a cheap-enough price. Most use ferrite rods or bars for their antenna, though the maximum length found is usually not more than 4 inches.

An old Japanese transistor radio from the early 1970s was procured early in the summer from the flea market. It did not work. Though I tried, I never was able to get it to work, but it had a nice 4-inch ferrite bar in it with intact coil. The miniature variable capacitor was sturdy and in good shape too, and it had a perfect little plastic clip which could be used to attach the capacitor to the bar. I decided to put the two together and make my own miniature "Q-Stick", so I disassembled the radio, removing these parts.


You see the result in the accompanying photos. The variable capacitor and clip were mounted to the bar, then the coil wire ends were soldered to the variable capacitor. Tuning is fairly sharp, particularly at the high end of the band, and I found it tunes the entire mediumwave broadcast band without problem. The resulting assembly can then be placed or held near a radio containing a loopstick antenna. The signal picked up by the tunable bar is inductively coupled to the radio's internal loopstick, increasing signal strength. Rotating the tunable ferrite bar produces a sharp null just like rotating the radio itself, and used in combination with the radio's nulling ability can produce some interesting results. My ultralights all have very short loopstick antennas, generally not much longer than 2-inches, so the 4-Inch Tunable Ferrite Bar does improve signal pickup quite dramatically on these units.

So, if you have an old transistor radio around that doesn't work anymore, don't throw it away. You might be able to make your own tunable antenna accessory.

Are Sunspots Disappearing (Forever)?

An interesting article appeared September 3, 2009 on the NASA Science web site asking this very question.

"Personally, I'm betting that sunspots are coming back," says researcher Matt Penn of the National Solar Observatory (NSO) in Tucson, Arizona. But, he allows, "there is some evidence that they won't."

"Sunspot magnetic fields are dropping by about 50 gauss per year," says Penn. "If we extrapolate this trend into the future, sunspots could completely vanish around the year 2015."

Check out this interesting article.

http://science.nasa.gov/headlines/y2009/03sep_sunspots.htm?list1066443

Favorite Frequencies?

Favorite frequencies? Seems like a silly question, "What are your favorite frequencies?" MW DXers are interested in any new, interesting, or rare DX, regardless of frequency. But many times, and more often than not, I find myself hanging out on certain same frequencies every night to see what might pop out underneath the usual pickings.

Here in Avon, New York, 20 miles south of Rochester, current evenings at sunset and beyond I am listening on 630 KHz for that big WMAL fade down (50KW, Washington, DC) to see what shows up underneath. Canada is well represented on this frequency, but there is a lot of weak US stuff underneath, many under 100 watts nighttime power. This is where the nulling proficiency and sensitivity of your radio is really tested.

850 KHz is another frequency I am checking now. WKNR, Cleveland, OH (4.7KW) usually dominates, and WKGE out of Johnstown, PA (10KW) broadcasting a baseball game, and WEEI, Boston, MA (50KW). But a few weeks ago I heard KOA, Denver, CO (50KW) fade up when the sun set at the Denver end. Who knows what else will appear in time?

1620 KHz is another favorite. One day I will catch WDHP out of Frederiksted, Virgin Islands (1KW) over the other weak offerings on this frequency. One day.


I am always checking the 570 KHz and 870 KHz Cuban frequencies for the Radio Reloj time ticks. In recent days last week good Cuban audio has been received on these two frequencies at 0600 local time. This is a good propagation indicator for the southern US like the Gulf Coast, and further into Florida or the Caribbean. The Cubans can be quite strong at times. Now that summer is dying and the Fall MW DX season is upon us, WWL, 870 KHz, New Orleans, LA (50KW) has been a power house here lately both in the evening and early mornings. Almost always underneath are the Cuban time ticks fading up and down.

The X-Band is always fun too, 1620-1710 KHz. 1630 KHz, another favorite, can be counted on most evenings to bring me KCJJ out of Iowa City, IA (1KW). They are often broadcasting a sports event. I have had WRDW from Augusta, GA (1KW) fade up and ID for me on occasion. However, I am looking for the elusive KKGM, Ft. Worth, TX (1KW) to appear.

820 KHz is another interesting frequency. It is sparsely populated, and a lot of what is there is low power. That is, all except for WBAP, Ft. Worth, TX (50KW). It will appear one of these days if I can get past WWLZ and WNYC, both New York stations, low power, but dominating. But I am always checking.

Those are some of my favorite frequencies of late. How about you?