Tag Archives: AM Radio

Eye On America: NC radio station becomes voice of recovery after Hurricane Helene

2 Replies

From CBS Evening News:

After Hurricane Helene devastated western North Carolina, a couple of radio broadcasters played a critical role in keeping residents informed. Now, six months later, they have taken on a new role in the recovery. Skyler Henry reports.

Click here to view on YouTube.

Having experienced the devastation of Hurricane Helene firsthand, I can confirm that this radio station, along with its FM relay, delivered crucial community updates when both internet and mobile phone services failed.?Never underestimate the power of local radio. — Thomas

Bob’s Radio Corner: Pairing a Phone or Tablet with a Radio

9 Replies

Pairing a Phone or Tablet with a Radio

By Bob Colegrove

The Internet is full of resources for radio listeners and hobbyists.  There are numerous examples of general information, frequency, and schedule lists.  There are also WebSDR sites, which allow you to compare reception experiences from around the world.  All of these can be accessed quickly and easily by having them loaded on your phone or tablet operating side-by-side with your radio and having Wi-Fi or cellular access.  We never had any of this when I was starting out.

I realize there are other ways to go about what I have described below, for example, merging station listings with SDR.  This posting is for folks like me who are SDR-challenged.  I listen to plain old radios.  My modern-day experience with newfangled technology has been limited to hitchhiking on WebSDR sites for the last few years.  It has served me well.

Ideally, I would like to generalize this topic to simply cover all phones and tablets.  In truth, my experience has been limited to an iPhone and Kindle Fire tablets.  They have worked very well as I shall explain.  Perhaps you have paired a different phone or tablet with your radio, in which case, feel free to share your experience.

The choice of a phone or tablet is yours.  Either works well.  Your decision will be affected by what you have available and what is easier to use.  If you intend to buy a new device and associate it with your radio, cost will be an additional factor.

A noteworthy device (the one I tend to favor) is a Kindle Fire.  Mainly, they are cheap.  The regular price of a 7-inch model is just under $60 and can often be purchased for less during Black Friday and Prime Day sales.  It is versatile, possessing all the usual functions except for cellular access.  Perhaps most importantly, it is virtually noise-free.  For a while I struggled using Internet sources on a laptop computer.  Even a good one located about 10 feet away from the radio antenna generates noise.  On the other hand, I have taken a 7-inch Kindle Fire in hand and placed it against the resonant coil of a loop antenna.  This abuse generated no more disturbance to the antenna than if it were a block of pinewood.  I have noticed some slight noise from the 11” Kindle when the antenna is exposed this way, but when that tablet is held at arm’s length from the antenna, all is well.  Recently, I have expanded this application to my iPhone and found its noise immunity matches that of the Kindle Fire 7.

Broadcast Schedules

The most useful Internet resources are the broadcast schedules.  These are the comprehensive frequency-time-station listings that tell us where and when to tune.  There are many good ones.  My favorites are the EiBi listing http://www.eibispace.de/, and Dan Ferguson’s https://groups.io/g/swskeds/topics.  For the latter you will need to request membership.  SWskeds merges EiBi, Aoki (https://www1.s2.starcat.ne.jp/ndxc), HFCC (https://new.hfcc.org/index.php), as well as other sources into a single list.

Processing

The EiBi listing comes as a CSV-formatted text file, which can be imported into a spreadsheet. I have done some processing using spreadsheet functions to produce a customized listing.  Processing the frequency-time-station lists is most conveniently done using a computer rather than the phone or tablet.   Processing includes selecting, arranging, or filtering the downloaded data tailored to your needs.  This might include adding a filterable column to indicate only stations that are on at the current time.  Some users might favor filtering by country or station. The heavy lifting processing is done automatically whenever a new listing is published by simply dropping the new file into the existing spreadsheet.  No, the functionality of a spreadsheet and ease of editing are not as good on a tablet as with the mouse and keyboard of a computer.  My processing on the computer includes measures to optimized the screen view to the most essential information thus minimizing the amount of scrolling on the tablet.

After the files are downloaded and processed, they can be loaded on the phone or tablet in a couple of different ways.  They can be directly transferred over a USB cable, or they can be transferred using a cloud server.  The USB cable-transfer method may be difficult on some devices, particularly iPhones.  The Kindle seems to be the more convenient device.  Being an obedient Microsoft customer, I can also transfer the files from my computer to OneDrive, then pick them up on the Kindle or iPhone using the OneDrive and Microsoft 365 apps which are available for both phone and tablet.

Examples

The screenshot below shows an EiBi example at 0014 UTC.  Although the “ON” column filter is set to show only transmissions currently “ON,” it had not been manually updated on the Kindle for a couple hours and thus includes listings from a previous time.  The EiBi database does not include transmitter power or beam information.  However, the identification of countries and transmitter sites is extensive.  These are determined by downloading and printing the README.TXT file on the EiBi site.

The SWSkeds listing is available in both CSV and Excel formats.  It contains several additional data fields, very importantly including transmitter power and beam direction when available.  For this list, I make the simple conversion of the existing Excel data range tab, “COMBINED” to a table so I can easily apply filters.  The screenshot below shows an example at 1750 UTC with the “ON” column filtered to “ON.”

Not to be left out, the complete medium wave broadcast station list for Region 2, the Americas, is easily downloadable at https://www.fcc.gov/media/radio/am-query.  The entire database is formidable and contains nearly 600 pages in a printable format.  Much of this bulk is due to the doubled size necessitated by giving both daytime and nighttime power separate entries for each station.  A number of marginally useful data columns can be eliminated in spreadsheet processing.  I have added formulas to calculate the azimuth heading and distance from my listening post (blanked out in the example below).

A variation of the downloadable file format is the direct-query site, SHORT.WAVE.INFO.  Here you can simply enter queries by station, language, frequency, or band, and produce listings which match your criteria.  Any listings which are currently on the air will be highlighted in red.

WebSDR

Finally, I would like to mention the WebSDR sites.  While not used explicitly for broadcast schedules, these sites are great for anyone wanting to compare how well they are receiving signals relative to what others are experiencing.  Granted, location and time of day are big factors that affect reception, but it is still useful to make these relative comparisons.

Home base is http://websdr.org/ which presents a catalog of many WebSDR sites by location.  At the bottom of the page is a world map which pinpoints the location of each site.  Most of these sites cater exclusively to hams; however, The University of Twente, Enschede, Netherlands (http://websdr.ewi.utwente.nl:8901/) covers 0.000 to 29.160 MHz unabridged.  The screenshot below shows the tablet/phone version of the U. of Twente site.  There are also two sites on the US East Coast which cover some non-hamband portions of the SW spectrum:  http://na5b.com:8901/ in the Washington, DC area and http://websdr.k3fef.com:8901/ in Milford, Pennsylvania.  The SHORT.WAVE.INFO and WebSDR sites can be directly accessed and queried over the tablet’s browser and a Wi-Fi or cellular connection.

Using the System

In my relentless pursuit to log the Nibi-Nibi Islands, I will load up one of the frequency-time-station listings and start my DX session.  This typically includes a scan of a particular band, checking signals I can receive against the lists.  If my interest peaks on a particular catch (usually a weak one), I will switch the tablet over to a WebSDR site to see how it is being received in Europe or along the East Coast of NA.

In summary, ready access to these Internet resources using a phone or tablet next to the radio has notable advantages:

  • The frequency-time-station listings provide quick, reliable signal identification in most cases.
  • The WebSDR sites confirm that my antennas are doing their job.

Am I done?  I hesitate to stop here.  The process of discovery is a marvelous human experience.  The foregoing are merely starting points.  Other applications might include sunrise-sunset calendars or maps or propagation forecasts.  There are certainly other ways to do all this depending on your druthers.  I know I am erring by omission and neglecting many other good resources.  Let’s hear about yours.

AM Band RF Noise Study

2 Replies

 

Photo by Brock Wegner on Unsplash

Many thanks to SWLing Post contributor, Dennis Dura, who shares the following article from Radio World:

NRSC Releases Details of AM Band RF Noise Study (Radio World)

Noise levels remained consistent throughout different environments, even in downtown Baltimore

The National Radio Systems Committee’s AM Improvement Working Group has published a study examining the effects of RF noise on AM radio reception in cars.

Radio World readers will find the study’s scientific detail of interest. Noteworthy was how RF noise on the road often did not vary amongst the diverse environments sampled. Overcoming downtown building signal degradation was more of a concern, according to the study’s authors. Additionally, the study found field strength projections of AM signals to often not be reflective of contour predictions.

The group’s study intended to provide a better understanding of how AM radio reception is affected by RF signal strength and noise in a range of roadway environments. The authors also provided some suggestions to overcome signal loss. [Continue reading…]

The ‘AM Radio for Every Vehicle Act’ is Back

10 Replies

Many thanks to SWLing Post contributor, Dennis Dura, who shares the following news via Radio World:

Markey, Cruz Reintroduce AM Bill in the Senate (Radio World)

The legislation would require AM radio reception in new cars

The AM Radio for Every Vehicle Act has been reintroduced on Capitol Hill.

The legislation passed the Senate Commerce Committee in 2023 and the House Energy and Commerce Committee in 2024, and many legislators have expressed support. Yet backers could not get it across the finish line at the end of the recent Congress in December.

Senators Ed Markey, a Democrat, and Ted Cruz, a Republican, now have reintroduced the bill, which has 40 Senate co-sponsors. [Continue reading…]

Responding to “The Colegrove Inspiration”

16 Replies

By Jock Elliott, KB2GOM

It was Bob Colegrove’s post — this one — that inspired me and set me on this path.

Medium wave broadcast band DXing (MWBCB) has a certain fascination for me, but I am poor at it. Oh sure, I have read the advice: map the band at noon, then again at midnight, and you’ll have a better idea of what’s unusual as you are tuning around. But I have never gotten around to doing the mapping, so my DXing skills are lousy at best.

When Bob asked, “What’s your favorite corner of the dial?”, he also mentioned the challenge hunting below 600 kHz. The implication: whatever is in that section of the band, there are probably not a lot of stations, and they are hard to hear. So, I reasoned in my tiny little brain: “If I hear anything down there, it’s likely to be DX.”

So I tried it, firing up the Grundig Satellit 800 hooked to an MFJ 1886 loop during the daylight hours. With exception of WROW, 590, in nearby Albany, NY, blasting oldies with 5,000 watts, I found nothing . . .  and I do mean nothing: nada, diddly, bupkas, cipher, rien . . . dead band . . . deader than old Jacob Marley. I try it again in the early evening with three different radios with exactly the same results. Nuts.

But then I try again with the Satellit 800/1886 combo at a little after 0900Z and take Bob’s advice about using single sideband. Aha! Carriers 540, 550, and 560. Then at 570, a weird mixture: religious programming in American English over male and female voices in Spanish with time ticks and tones in the background. Is there a time station on this frequency or is it some sort of bleed-over?

On Tuesday evenings I run the Radio Monitoring Net on the 146.94 repeater. During the net, I mentioned the unusual signal I had heard on 570, and W2SRA, an expert DXer, responded with the opinion that this was likely a religious station on Long Island, NY, intermixed with a station known as The Clock from Cuba.

Here’s what Wikipedia has to say about it: Radio Reloj (Spanish for Radio Clock) is a government-owned Spanish-language radio station in Cuba . . . The station is noted for the sound of a ticking clock in the background, with its hosts announcing the time, every minute of broadcast.

I checked the distance from Troy, NY, to Santa Clara, Cuba where the 570 AM station is located; it’s 1449 miles. Wow! According to Wikipedia, the AM transmit power is 50,000 watts

Then I remember that William, KR8L, mentioned that he likes searching above 1620 (another less populated region of the band), so I give that a try. At 1690, I hear oldies, followed by ads for Southern Maryland. The station finally ID’s as WPTX, 1,000 watts nighttime power, in California, MD, a distance of 339 miles. Yes!!

Thanks, Bob and William, for turning me on to some more radio fun!

Bob asks: “What’s Your Favorite Corner of the Dial?”

17 Replies

Many thanks to SWLing Post contributor, Bob Colegrove, who shares the following guest post:

What’s Your Favorite Corner of the Dial?

As asked by Bob Colegrove

Let’s suppose you’ve been listening to radio for a while.  Consciously or not, you’ve probably favored a range of AM, SW, or FM frequencies.  These are areas where you go to DX or just listen to your favorite stations.  One area I seem to keep returning to is the very bottom of the medium wave band, roughly 530 kHz to 600 kHz.  With the convenience of today’s digital radios, I have consciously pushed the envelope somewhat lower.

The main reason for specializing in that frequency range is the challenge.  In the very beginning there didn’t seem to be much at the extreme lower end of the AM broadcast band.  Growing up in Indianapolis in the ‘50s, the local stations were all at the upper end of the mediumwave dial.  WXLW held down 950 kHz – lower than that nothing.  I would say the stator plates on the variable capacitor got very dusty, never being closed any further than that on many radios.

Another challenge was sensitivity.  In analog times, the sensitivity of a tuned circuit had some falloff as the inductance/capacitance (L/C) ratio decreased.  Sensitivity is highest with the variable cap open at the high end of the band.  As you tune lower by increasing capacitance (inductance remaining constant), the Q and consequently sensitivity drop off – not dramatically, but somewhat.

Finally, not all old analog radios tuned to 530 kHz; some were even challenged to tune 540 kHz.  By performing a little mischief with the alignment, I could sometimes venture into unknown territory.

This was all part of the challenge.  So, what could I do to coax some activity out of the bottom of the band?  I spent many hours poring over Bill Orr’s Better Shortwave Reception (Radio Publications, Inc., Wilton, CT, First Edition, 1957) and tweaking caps and coils trying to squeeze the last few kilohertz and microvolts out of my radios.  This exercise fascinated me and became a hobby within a hobby.  If I may be allowed a self-deprecating aside here, the first time I took a radio out of the cabinet, I just assumed that all these alignment screws were loose, and dutifully torqued them down.  The alignment problem is not comparatively complex with today’s digital receivers.  Note, I didn’t say it was unimportant.

I still tend to favor the bottom of the medium wave band.  Below is a list of my catches over the past couple of years.  It’s just a sample of what one might hear by casual listening over time.  Highlighted stations are heard during daylight hours.  This is NOT intended to impress anyone, rather it is hopefully a stimulus for your own efforts.

As another attraction of the lower mediumwave band, you will find a potpourri of stations.  Besides regular North American broadcasting stations, one might possibly hear an occasional high-powered trans-Atlantic station which is not synchronized with the 10 kHz spacing.  530 kHz is interesting.  It is not used in the US by commercial broadcast stations.  Instead, stations from Canada and Cuba at roughly orthogonal directions from me are regularly audible at night on this frequency.  Thus, the radio is tuned by simply rotating the antenna.  530 kHz is also home to several Travelers’ Information Stations (TIS) throughout the country.  Question:  How will this long-time service fare if travelers don’t have AM radios in their new cars?  Finally, the very bottom of the frequency range still contains a few holdouts of non-directional beacons.

Frequencies below 530 kHz probably put a strain on the medium wave bands of old radios, but they are likely no problem on most digital radios having both LW and MW coverage.  As mentioned, there are a few non-directional beacons down there.  They are Morse coded using amplitude modulation.  I have found placing the receiver in SSB mode makes detection much easier, as the heterodyne from the carrier can be heard well before the signal is strong enough to produce any audio.  These beacons generally fade in for brief periods of time and then fade out like passing comets.

My most recent catch was experimental station WI2XLQ, 486 kHz, during its annual Fessenden Event on Christmas Day and again on New Year’s Day.  See https://swling.com/blog/?s=Fessenden+ .  The experience was not the armchair listening quality one might expect from FM or the Internet.  Instead, it was weak and fraught with atmospheric noise.  The station came in periodically, then disappeared, in short, DXing to its highest degree of satisfaction.

The antenna is the key to good reception, and there is no exception to this rule at the lower end of the AM band.  Many years ago, I switched to an indoor, resonant loop antenna.  The selectivity, directional properties, and noise rejection of a loop antenna in this frequency range are superb.  The figure below shows my 40-year-old loop antenna, which is still used in its original form.  It tunes from ~485 kHz through ~1710 kHz in two bands.  The antenna can rotate 360 degrees horizontally and 90 degrees vertically.  Further, it is mechanically balanced to remain in any position without locking.  For those not inclined to construction projects, the Tecsun AN-100, AN-200, and Terk Advantage will perform quite well through inductive coupling with a portable radio’s ferrite bar antenna.

As all experienced medium wave DXers know, for success you need to have patience, “set a spell,” and let the radio do its thing.  Radios are living organisms, kind of like cats, very independent at times, and will let you hear only what they want you to hear.  On many channels, stations will come and go over time.  If you’re lucky, you might catch an ID; lacking that, you might be able to identify it by the format or network.  You might try to compare the contents you hear on the radio with what you can hear online either over the station’s website or via streaming sites such as TuneIn, iHeart, or Radio Garden.  There may be a delay between the Internet stream and the live signal.

When you feel you’ve exhausted the possibilities, there’s still more.  Turn the antenna 90 degrees and start over.  You’re only half finished with that frequency.  Don’t forget a headset or earbuds.

What’s the next challenging rung on the limbo bar?  Well, possibly the 633-meter ham band, 472 to 479 kHz.  I’ll have to pad the old loop with a small capacitor to tune down there.

What’s your favorite corner of the dial?  Why?