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Many thanks to SWLing Post contributor Paul Jamet, who shares the following update and QSL card images related to Bulgarian National Radio (BNR) and Radio Bulgaria.
As Radio Bulgaria looks ahead to its 90th anniversary in 2026, Bulgarian National Radio has announced a new commemorative QSL card series for listeners who submit reception reports. The series will include 12 different QSL cards, each highlighting a key moment from the history of BNR and the Radio Bulgaria service. According to BNR, a new card will be released each month, along with a short publication explaining the historical background behind the featured image.
Paul also points to a broader retrospective titled “BNR at 90 – A Story of Pride and No Prejudice,” which looks back on nine decades of Bulgarian National Radio. The piece reflects on BNR’s history through periods of political change and technological transition, while underscoring the role of public broadcasting in preserving culture and maintaining a connection with international audiences.
Attached at the top and bottom of this post are two QSL cards from Paul’s own collection.
Many thanks again to Paul for sharing both the news and the QSL images!
During the Cold War years, many different signals could be found on shortwave that cannot be heard today. For example, there were two Germanys, several broadcasters from the USSR not including Radio Moscow, Radio Free Europe and others.
I have uploaded audio clips of these stations and others to the InternetArchive.
If you were adventurous like me, willing to tune outside of the regular assigned broadcast bands, and flip the BFO switch “on”, stations with odd sounding names like Giant Step, Sky King, Fanfare or Ivanhoe could sometimes be heard. These were typically tactical calls used by the U.S. military.
I recently dusted off an old 3-ring binder to look up what were some of the tactical callsigns that I was able to log from my southern Ontario listening post. They included Missionary, Toreador, Democrat, Retail, and Capsule.
My old recordings of stations “Pawnee” and “Fanfare” can be found on the Internet Archive here:
Information about these stations was hard to find, however, radio hobby magazines and SW club monthly bulletins were a good place to look. I have reprinted (below) some related material from Communications World magazine, which ran from 1971 to 1981.
If you would like to browse through all of their publications, follow this link:
“The Navy also has its point-to-pointers, including NSS, Washington D.C.; NPM, Pearl Harbor, Hawaii; and NPG, San Francisco. Overseas there are Navy stations in many locations, such as Naples, Italy (NNI), Londonderry, Northern Ireland (NST), Roosevelt Roads, Puerto Rico (NRR), San Miguel, Philippines (NPO), and elsewhere. Some military stations use tactical call names, rather than call letters, which makes the DXer’s hopes of identifying them rather slim. For security reasons these stations identify with names such as Overland, Kingfisher and the like. These call names are changed frequently and seldom is the hobby listener able to figure out just where the station he’s hearing is located. Some of these identifiers have been used so consistently, over the years. that DXers have managed to figure out their real identities. Toreador, for instance, is a name used by Navy Operational Radio, San Francisco; Pacific Radio is at Pearl Harbor; Ivanhoe is the U.S. Naval Communications Station, Norfolk, Virginia; and a whole series of stations using the code name Raspberry (as in Raspberry Jax, located at the Naval Air Station, Jacksonville”
CW Spring-Summer 1975 page 36
“SWLs will soon note that the armed forces don’t always use call letters. Instead, tactical call signs may be used to identify the station. You might, for instance, hear a station calling itself Ivanhoe or Capsule. Looking Glass or Migraine. Some tactical calls are changed frequently, others are used year after year and, as a result, no longer pose identification problems for the utility SWL. “Ivanhoe” is the identifier used by the Navy’s important Norfolk, VA base. Navy installations in Morocco. Iceland and Spain identify as “Fanfare,” “Port Call,” and “Pawnee,” respectively. The U.S. Air Force’s Strategic Air Command (SAC) has for years maintained a regular airborne alert. It is no military secret that at any time, day or night, SAC has jumbo bombers aloft—supposedly loaded with nuclear armaments—in readiness to retaliate should this country ever come under attack from an enemy. Clearly it is essential that these planes keep in continuous contact with ground command stations. Shortwave radio is one of the means employed. This SAC radio network is known as Sky King. Coded communications pass between SAC bases and the jets probably several times each hour. SWLs who stumble on these transmissions will hear, as part of the routine radio traffic, authenticator codes, usually two phonetic letters such as “Alfa-Tango.” The purpose of these codes is to assure plane commanders that the rest of the message is genuine. Various Air Force bases identify themselves in radio communications either by base name, such as “Hickam” (Hawaii’s Hickam Air Force Base), or by tactical calls. “Democrat” is used by March AFB, CA, and “Retail” is the call of Barksdale AFB, LA. SAC also has a flying command post, a back-up measure that supposedly would take command of SAC forces should “a nuclear attack wipe out the headquarters at Offutt AFB, NE. The command post in the sky uses the tactical call “Looking Glass.” Some SAC frequencies to watch are 6,762, 9,027, 11,220, 13,245, 14,744 and 17,875 kHz. There are other Air Force frequencies to watch for plane-to-ground. and vice versa, transmissions. Among them are 6,738, 8,764, 8,988, 9,020, 11,200. 13,201 and 17,993 kHz. “Raspberry” is a network tactical call used by naval air stations. “Raspberry Miramar” is the station at Miramar NAS, CA, and “Raspberry Jax” is Jacksonville, NASFL. You can find naval air communications in the 6.7, 8.7, 8.9, 11.2, 13.2 and 15.0 MHz frequency areas.”
CW (Fall-Winter 1976) pages 19-20
“The list of tactical calls is as long as your arm and most DXers find it very tough to connect a certain call with a particular service or military base. But here is a partial list of calls used by Air Force, Navy and a few Army operations. (Bergstrom AFB, TX), “Condor” (land mobile units), “Raymond 6” (George AFB, CA), “Raymond 24” (Little Rock AFB, 4LR). Pacific Missile Firing Range Network: “Plead Control” (Pt. Mugu, CA), “Outrider Control” (Barking Sands, HI). Strategic Air Command: “Skyking” (general call for airborne aircraft), “Outway” (Offutt AFB, NE), “Retail” (Barksdale AFB, LA), “Democrat” (March AFB, CA). Other Air Force “tacticals”: “Beaver Operations” (Ellsworth AFB, SD), “Letterman” (Hickam AFB, HI), “Hornpipe” (Cannon AFB, NM), Air Force Tactical Air Command: “Mainsail” (general call), “Fireside 1” (Langley AFB, VA), “Fireside 5” “Glucose” (Seymour -Johnson AFB, NC), “Lactose” (Shaw AFB, NC), “Fertile” (Homestead AFB, FL), “Acrobat” (Andrews AFB, MD), “Ringmaster” (NORAD Hq, Cheyenne Mt., CO), “Gull Monitor” (Keesler AFB, MS), “Format” (McGuire AFB, NJ). Navy Atlantic Command: “Ivanhoe” (Norfolk, VA), “Hampshire” (Ft. Allen, Puerto Rico), “Sheriff” (Bermuda) “Phenomenon” (Jacksonville, FL). Navy Pacific Command: “Butterfield” (San Diego, CA), “Dunkirk” (Honolulu) Other Navy “tacticals”: “Climax” (USS Enterprise), “Eagle Cliff” (USS .John F. Kennedy), “Jitterbug” (Balboa, Canal Zone), “Artesia” (Keflavik, Iceland) “Orange Juice” (Guam), “Missionary” (Norfolk, VA), “Top – hand” (Chief of Naval Operations), “T – Bone” (Adak, AK), “Sleepy Hollow” (Cutler, ME). Army “tacticals”: “Agitator” (Ft. Bliss, TX), “Civil Genius” (Ft. Huachuca AZ), “Popeye” (Ft. Bragg, NC), “Avon Studio” (Ohio National Guard), “Contact Tippic” (Indiana National Guard), “Flame Ivory” (Pennsylvania National Guard).”
I wonder if anyone else recalls hearing these? Please comment!
In the late ‘60s, I worked as a mechanical assembler at Communications, Electronics Inc. (CEI) in Rockville, Maryland (acquired by Watkins-Johnson Company). We produced military-grade receivers, mainly for the military (whom else?). These covered the spectrum from VLF through microwave. It was the early days of electronic digital readouts. There were no LEDs or LCDs. Instead, some of our models featured the Numeric Indicator eXperimental, or “nixie” tubes. These were glass tubes filled with low-pressure neon/argon gas, featuring stacked wire cathodes shaped like numerals (0-9) and a mesh anode. An analog-to-digital circuit encoded the frequency to illuminate the correct digits.
Below is shown a DRO-50 Digital Readout from the 1968 CEI catalog. It contained 6 nixie tubes for the frequency display, and the unit had an accuracy of ±100 Hz. Interestingly, this frequency display was designed specifically for the Hammarlund SP-600 Receivers (R-274A/FRR (Army), R-274B/FRR (Navy)). I never saw a DRO-50 come across our line and suspect it may not have gone beyond the prototype. About that time, the SP-600s were ending their military service, so there wasn’t much of a market for upgrades. It would still be a few years before I owned an SP-600 of my own, but how would I love to have one fitted with a DRO-50.
What I had instead of nixie tubes were variable capacitors or inductors, which changed the tuned frequency through a kluge of pulleys and strings, all these hidden behind a Raymond-Loewy-designed bezel and operated by the tuning knob.
What was visible on the front of the radio was an irregular representation of frequencies covering the tuning range of the radio, in other words, the dial. As you rotated the tuning knob, you set the whole tuning mechanism in motion. Signals were progressively tuned, processed, and reported through the speaker or headset as you advanced higher or lower.
Somehow the frequencies never quite agreed with the numbers or divisions on the dial. It could be that the circuits inside the radio were out of alignment. Just as likely, the design of the dial was determined using a preproduction prototype which could not possibly account for the tolerances of the components used on the assembly line.
Consider the figure at the beginning of this posting. It is a portion of the dial on a Hallicrafters S-38E – magnified somewhat. The full dial on the E model was big and bright. It extended across the front panel of the radio and presented frequency readout about as well as was possible. Nevertheless, there were real shortcomings.
The figure is not only typical if communication receivers of the time but also living room console radios of an earlier period. Take the 31-meter band as an example. Broadcast stations were bunched roughly between 9400 kHz and 9800 kHz. At 5-kHz channel spacing, this resulted in roughly 80 channels. Of course, not all were in use at any given time, but still a smidgeon turn of the knob could traverse two or three stations.
This situation was relieved somewhat on communication receivers by the addition of a bandspread – a separate tuning mechanism which could effectively magnify a small portion of the main dial. The idea was to place the main tuning dial at the high end of the desired band and the bandspread at 0. Then, by tuning the bandspread toward the other end, lower frequencies could be tuned with greater separation.
Since the bandspread could be used at any place within the tuning range of the radio, a separate dial became a problem, so it was usually annotated with a simple logging scale incremented linearly from 0 to 100. Thus, one had to compile a log-to-frequency conversion table or graph to interpret the frequency. More sophisticated receivers could display the 80- through 10-meter ham bands on the bandspread dials.
As an example, I located some notes made in 1959 using the S-38E. The table shows the frequency, bandspread reading, station and country. Thirty-one meters was an easy match for the bandspread, as WWV on 10000 kHz was a steady marker which you could use to calibrate the bandspread with the main tuning. For all practical purposes, the band was bounded by the Voice of Spain on 9360 kHz and R. Budapest on 9833 kHz. For many years, Tel Aviv was an outlier on 9009 kHz.
Alternately, one could construct a graph as shown below. Unfortunately, most inexpensive radios did not produce linear tuning, so you couldn’t simply draw a straight line between two points on a graph and expect to interpolate the intermediate frequencies with accuracy. Instead, graphs were constructed laboriously by hand adding intermediate points for known frequencies. The figure shows the resulting parabolic function where the slope is greater on higher frequencies and gradually levels off as the bandspread is tuned lower. Notice that most of the activity was mashed between 40 and 60 on the bandspread, then compare this with the picture of the bandspread above.
On the S-38E a bandspread was something of an improvement, but not the complete answer. The problem only got worse as you went higher in frequency. At 19 and 16 meters the band compression became quite severe.
Our esteemed leader, Thomas, occasionally uses a picture of the dial shown below as a lead figure of a posting. It is possibly an RCA Victor Model 110k console radio. When I see this, I think, who wouldn’t give a king’s ransom to own that radio in its fully restored condition? Note the 31-meter band has been magnified as its own separate band and appears in a near linear progression. Thirty-one meters was arguably the center of international shortwave broadcasting in the golden age.
Have you ever wondered what the rest of that radio looks like? Here’s one in sore need of some Pledge. Now imagine yourself, perhaps 11 or 12 years old, perched in front of it on your grandmother’s needlepoint stool tweaking the dial. If you have experienced this, no explanation is necessary. If you haven’t, none is possible.
So, as it turns out, I have tempered my earlier conviction that a digital frequency readout is necessarily better than a classic dial. Not to say you can easily pry the PL-880 with 10-Hz resolution from my cold, stiff hands, but I have come to realize that intrigue and mystery of shortwave listening rested in the uncertainty of knowing exactly what frequency you were on. There was always the possibility that the elusive Nibi Nibi Islands lay somewhere near the shadow cast by the dial pointer. It was a land of enchantment, and once you left its borders, you could never return again.
50 years ago, Voice of America broadcasts could be found all over the shortwave dial.
In addition to a number of transmitter sites located stateside, the VOA used to broadcast from a number of other facilities located in overseas countries in order to help get its signal into all corners of the globe. Many of these “relay” stations made for challenging DX catches and there was even an award offered by NASWA to those providing sufficient proof of reception of them all. An example of this can be found on this link: https://k5nd.net/2011/06/voice-of-america/
The familiar tune of Yankee Doodle (heard at the beginning and end of a transmission) along with station ID in English would often include the particular transmitter site in use. Several old recordings of these can be found on my links to these on the Internet Archive.
Technical staff hired to help maintain equipment at overseas facilities were often licensed amateur radio operators. See the attached scans of two QSL cards from amateurs who worked at the station near Monrovia, Liberia.
Most of the various VOA transmitter sites are listed below. Some include links that will lead to related historical information, articles and/or photographs and are well worth exploring.
A year ago, in January 2025, I made a couple of recordings, using remote SDR receivers, of some Voice of America programs being broadcast from their Botswana transmitter site. These have been uploaded to archive.org and can be found here: https://archive.org/details/voa-africa-via-botswana-relay-january-19-2025
Since March 16, 2025, it seems the only former VOA transmitters being used are Greenville, NC (Radio Marti), Tinang, Philippines (Radyo Pilipinas world service), and Wooferton, UK (BBC and others).
Attention all SWL’s! For those of you with a little extra free time over the holiday season, I would highly recommend having a look at two books that were written by a couple of very respected DXer’s from the past. They are both available on the Internet Archive and their respective links can be found below.
Shortwave Voices of the World by Dr. Richard E. Wood (1969)
I have mentioned this one before, but in case you missed it, you will find it here.
Newly uploaded, this one comes in two parts. Part One describes his early days and how his listening began, while Part 2 gets into the hobby in general.
Many thanks to SWLing Post contributor Dan Greenall, who shares the following guest post:
The 90 metre band – Then and Now
by Dan Greenall
A few decades ago, the 90 metre shortwave broadcast band used to be full of interesting and challenging-to-hear DX signals. In the 1974 edition of The Complete Shortwave Listener’s Handbook, author Hank Bennett reports on what you might expect to hear on these frequencies. There is a copy of this book on the Internet Archive. Here is a link to that specific page.
Also, this sample page from White’s Radio Log in the 1972 Communications World magazine shows a number of stations that could be logged in 90 metre band.
Here are a few links to recordings from my personal collection that have survived through the many years. These were all made between 3200 and 3400 kHz from my listening post in southern Ontario, Canada.
[Note: Click on each broadcast link to open the associated Internet Archive page with more info.]
Today, it seems that only a handful of stations can be found broadcasting in the 90 metre band. These would include WWCR in Nashville, the Voice of Indonesia, KCBS Pyongyang and Radio Mosoj Chaski in Cochabamba, Bolivia. As well, the Canadian time signal station CHU still continues to use 3330 kHz.
A recent recording of Mosoj Chaski Radio, a Christian broadcaster logged using a remote SDR in Lima, Peru, is presented here.
Although not in English, listen carefully and you can hear them give their frequency of 3310 kHz in the 90 metre band as well as their location of Cochabamba, Bolivia.
Many thanks to SWLing Post contributor Dan Greenall, who writes:
I have lived in southern Ontario, Canada my entire life, have been DXing since the late 1960’s and have held the amateur radio call sign VE3HLC for over 50 years. Most of this area’s AM broadcast stations had been considered “pests” over the years as I searched for more distant targets, until recently, when many of these began quietly slipping from the airwaves. While this opened up some new frequencies to DX, I soon began to feel that I had lost some old friends, many that I had known since childhood.
When I retired in 2018, I decided to spend a little time trying to preserve some radio history of stations in southern Ontario communities that have played a part in my life. This might include audio clips, QSLs, station booklets, and other types of ephemera, and I would try to place this information where it could be easily accessed by future historians or anyone else who is interested. In the end, I chose to use the Internet Archive (archive.org), where most uploaded information can be viewed (or heard) and downloaded for free.
CFPL, London, Ontario 980 kHz (still on the air)
“Communications in the Community” is a hardcover limited edition (2000 copies) souvenir book printed in 1966 by the Special Printing Unit of The London Free Press in London, Ontario, Canada. It includes historical information about the London Free Press (newspaper) and CFPL radio and television. I was lucky to find this item at a church rummage sale nearly 20 years ago.
CFPL began its life as CJGC in 1922. I acquired one of their QSL cards from 1925 through an eBay purchase a few years ago.
The above and more can be found by clicking on this link.
CKOC, Hamilton, Ontario 1150 kHz (still on the air)
CKOC radio in Hamilton also started up in 1922. My parents met while working at the station in the late 1940’s. My brother and I (both radio amateurs), along with a few friends were given permission to operate on “Field Day” weekend in 1985 from their old abandoned transmitter site at Elfrida, Ontario.
This area has long since been developed to build homes and shopping areas.
“This is Hamilton, Ontario and the story of broadcasting station CKOC” is an undated booklet (I am guessing circa 1950) that I was able to purchase on eBay. Also found on eBay were two verifications, one from 1931 and the other from 1983.
You can find these scans and more by following this link.
This station began in 1926 using the unusual call sign 10BP. It would remain that way until 1935. I managed to secure this QSL from 1932 through eBay, signed by its founder W.T. “Doc” Cruickshank.
Interesting stories of how the station began can be found at this link.
CKCR, Kitchener-Waterloo, Ontario 1510 kHz (no longer on the air)
In 1924, this station began briefly in nearby Brantford, Ontario. It quickly moved to Kitchener-Waterloo and existed until 1965 when it became CKGL. The CKCR call sign was picked up later in 1965 by a station in Revelstoke, BC.
Another eBay purchase, I found this QSL with a not-to-scale map of southern Ontario from 1934.
I would encourage others to save parts of the local radio history in their city, state, province or country and give back to the hobby that we have enjoyed for so many years. I would also be happy to hear about any efforts you have made!
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Many thanks to SWLing Post contributor Paul Jamet, who shares the following update and QSL card images related to Bulgarian National Radio (BNR) and Radio Bulgaria.
