Category Archives: Guest Posts

Shortwave on the big screen

Greetings to all SWLing Post community, here’s a couple of programmes we’ve lined up for you this week.

We bring you Downbeat on Shortwave on Saturday 5th July 2025 at 1100 hrs UTC on 6160 kHz and then again on Sunday 6th July 2025 at 0900/1300 hrs UTC on 6160 kHz and at 2000 UTC on 3975 kHz and 6160 kHz (via the services of Shortwave Gold). Guest DJs Jesse Yuen and One Deck Pete bring you two 15 minute downtempo mixes each of some ambient and downtempo vibes to help you drift away. Expect some blissful vibes for a Sunday.

And we’ve got an episode of the SkyBird Drive in Radio on Wednesday 9th July 2025 via WRMI.

Make yourself a tasty snack (hot dogs, tacos, ice cream or burgers) and turn on that in-car shortwave AM radio for the full sound experience. Imagine you’re in a big cadillac, tilt your seat back (but not too far) and enjoy all sorts of cinema related tunes as you would in an outdoor experience (unless you are listening to the radio outdoors). Enjoy our evening’s programming.

Here’s a trailer about the Skybird Drive in to get you in that cinematic mood.

For more information on all our shows, please write to imaginarystations@gmail.com and check out our old shows at our Mixcloud page here.

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Radio Lavalamp reimagined

Greetings to all SWLing Post community, here’s a couple of programmes we’ve lined up for you this week.

We bring you a double dose of Radio Lavalamp, inspired by a low powered community and internet radio station from Osaka, Japan now reimagined by Imaginary Stations. Expect some way out sounds from all genres from the groovy to ethereal.

We’ve got programme one on Saturday 28th June 2025 at 1100 hrs UTC on 6160 kHz and then again on Sunday 20th June 2025 at 0900/1300 hrs UTC on 6160 kHz and at 2000 UTC on 3975 kHz and 6160 kHz (via the services of Shortwave Gold).

And programme two of Radio Lavalamp on Wednesday 2nd July 2025 via WRMI. It’s going to be a groovy trip via the ionosphere so tune in and turn on as many times as you like next week.

Here’s a trailer of an old show of Radio Lavalamp to get you in the ethereal mood.

For more information on all our shows, please write to imaginarystations@gmail.com and check out our old shows at our Mixcloud page here.

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WA2XMN Revives Armstrong’s Legacy with 90th Anniversary Broadcast on 42.8 MHz

Many thanks to SWLing Post contributor Conrad Trautmann, who shares the following guest post:


42.8 MHz WA2XMN FM Goes On The Air!

6/19/2025

By Conrad Trautmann, N2YCH

Stephen Hemphill, WA3ZAE, the owner of Solid Electronics Laboratories, fired up a vintage FM tube Phasitron transmitter on 42.8 MHz to put WA2XMN on the air at exactly 12:30 pm EDT today from the famous Armstrong Tower in Alpine, New Jersey. “W2XMN” was the call sign of Edwin Howard Armstrong’s experimental FM station that went on the air in 1936. “WA2XMN” is the official FCC call sign for the station Hemphill constructed with the cooperation of the tower site owners to commemorate Armstrong’s contribution to radio, Frequency Modulation.

W2XMN building at the Alpine Tower site

Hemphill explained that he attended a Society of Broadcast Engineers meeting that was celebrating Armstrong’s accomplishments, which sparked the idea of going on the air again on that original frequency. He thought it would be perfect to aim for the 70th anniversary of the first public broadcast of wideband FM. That anniversary celebration and broadcast was held on June 11, 2005. Today’s broadcast marks 90 years since that first FM Broadcast and 20 years since the commemorative event.

Hemphill built a transmitter based on the design of a General Electric BT-1-B, but on the lower frequency than what we now know as the standard FM band. Once turned on, the transmitter made 250 watts with no problem with a little headroom to spare and after warming up and settling in, had less than one watt reflected into 400+ feet of 1 ¼” transmission line into a vertical “ringo” antenna on the top, Western facing arm of the famous tower.

Stephen Hemphill poses with his Phasitron FM transmitter tuned to 42.8 MHz

Dual Eimac 4-250a power amplifier tubes

Armstrong Tower in Alpine, NJ (the vertical antenna is up there, trust me)

The audio broadcast today was mostly replays of the 70th anniversary event recordings. A temporary studio was set up in the tower site office building. The event was also streamed live over the internet.

WA2XMN temporary studio and audio processing.

Stephen Hemphill at the controls

The main audio mixing console used was a Gately Electronics Attache Case six channel mixer. Audio processing was done with a vintage Orban Optimod 8100A.

Gately Electronics Attache Case Mixer (apologies to all audio engineers for the pinned meters)

During the event, a web site address for enthusiasts to provide reception reports was given out. While we don’t have those reports yet, I contacted an amateur radio friend who was able to hear the station clearly 61 miles away in Ronkonkoma, NY on the eastern end of Long Island. That’s pretty good coverage for 250 watts!

Coupled with the special event broadcast was the annual picnic gathering of the New York Chapter of the Society of Broadcast Engineers, Chapter 15. Roughly 45 people attended and in addition to seeing the WA2XMN transmitter, they also got a first hand look at a few of the old Empire State Building FM Master antenna elements. Here’s a photo of your author standing next to one for perspective. I’m 6’ 5”.

To read more about this antenna and its history, visit this page researched and written by Paul Thurst, KH2R, owner of the “Engineering Radio” blog.

Conrad, N2YCH with an Alford antenna element from the Empire State Building

More rotations (per minute) around the earth

Greetings to all SWLing Post community, here’s what we have going up into the ionosphere and via skywave propagation this week.

Firstly we bring you the third instalment of Starship Skybird on Saturday 21st June 2025 at 1100 hrs UTC on 6160 kHz and then again on Sunday 22nd June 2025 at 0900/1300 hrs UTC on 6160 kHz and at 2000 UTC on 3975 kHz and 6160 kHz (via the services of Shortwave Gold).

Expect more sounds from across the cosmos, a big Houston style countdown when we start the show and music from DJs wearing space suits. It’s going to be one transmission full of atmosphere!

On Wednesday 25th June 2025 via WRMI  at 0200 UTC we bring you WORK. We’ve just checked AI to find out what the concept of work is, and we’ve found out, “In general, work refers to any activity involving physical or mental effort, done to achieve a purpose or result.” Tune in on Wednesday when the manager isn’t looking and enjoy the show!

More on Starship Skybird here:

For more information on all our shows, please write to imaginarystations@gmail.com and check out our old shows at our Mixcloud page here.

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Orbiting outer space via shortwave

Greetings to all SWLing Post community, we are off in orbit again on those shortwaves of ours, bringing you a couple of interesting shows to hopefully pique your imagination.

The first Imaginary Stations offering is on Saturday 14th June 2025 at 1100 hrs UTC on 6160 kHz and then again on Sunday 15th June 2025 at 0900/1300 hrs UTC on 6160 kHz and at 2000 UTC on 3975 kHz and 6160 kHz (via the services of Shortwave Gold) and it’s the second episode of Starship Skybird.

Like our first episode do expect more sounds from space, tunes from across the cosmos and if all goes well, we’ll have a reknowned astronomer on hand to give us a live commentary on what they can see in the night sky from the station’s roof (subject to weather and atmospheric conditions of course). Tune in that shortwave radio and join us reaching for the stars and beyond!

On Wednesday 18th June 2025 via WRMI  at 0200 UTC we bring you some audio excitement with the Kearsarge Mountain Transmission Service, KMTS. Expect some strange and wonderful music and sounds from the radio spectrum. 

More on Starship Skybird here:

For more information on all our shows, please write to imaginarystations@gmail.com and check out our old shows at our Mixcloud page here.

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Bob’s Radio Corner: Tuning Single-Letter Cluster Beacons

Source: Better Shortwave Reception, William I. Orr, W6SAI, Radio Publications Inc., Wilton, CT, 1st Edition, p. 25, 1957.

Tuning Single-Letter Cluster Beacons

by Bob Colegrove

Part of the allure of shortwave listening for me has always been vicarious visits to “those faraway places with the strange-soundin’ names.”  After one has logged several big-time broadcasters, one begins to look for new challenges.  Most of the so-called “utility” content which once occupied the space between the broadcasters and hams is now a vast open desert interrupted only with an occasional digital buzzsaw, a wide-band CODAR experiment, or some RTTY.  But now and then you come across a signal that grabs your interest.  In this case it happens to be a group of signals referred to as the Russian single-letter beacons.  A good introduction to these beacons is here

https://en.wikipedia.org/wiki/Letter_beacon

and here

https://www.hfunderground.com/wiki/Letter_beacon.

After many years, there is still some speculation as to the history, purpose and power of the single-letter beacons.  Rather than repeat what has already been said, this posting focuses on my technique for monitoring a subset of these beacons called “cluster beacons.”  They are called that because they are grouped close together, just 100 Hz apart, at ten different locations across the shortwave spectrum.  A good tabular summary is at https://priyom.org/military-stations/russia/single-letter-beacons.  Some stations may not currently be broadcasting or may be on at selected times.

These stations will neither captivate you with content or readily QSL.  They are all continuous wave (CW) and are thus heard by turning on your radio’s beat frequency oscillator (BFO) or selectable sideband (SSB) detector.  I am Morse-code-challenged – always have been.  Fortunately, these stations all broadcast their single letter dits and dahs repeatedly and slowly.  Having relatively low power, the challenge here on the East Coast of North America is just to pick them up through the band noise.  Some nights are better, some not so good.

For purposes of this posting, I have focused on the stations around 7508 kHz.  This seems to be the best cluster, at least at the current time and location.  “D” is invariably the strongest and most consistent, with “P,” “S,” “C,” and “A” fading in and out at different times depending on the propagation.

To tune through the cluster, first tighten up your selectivity as narrow as possible – 500 Hz if you have it.  Use the fine-tuning control – 10 Hz if you have it.  The best way to catch these beacons is to sneak up on them.

  • Approach upward from the low side of the cluster using USB, start tuning around 7508.3; or
  • Approach downward from the high side of the cluster using LSB, start tuning around 7509.5.
  • Try tuning in both USB and LSB to determine the better reception of the signal you are trying to hear.

Depending on which signals are audible, you may hear two or three making it through the 500 Hz filter at the same time, each with a different pitch.  The beacons will change pitch as you approach, going from a high pitch heterodyne to a lower pitch.  When you reach zero beat with a station you will be directly on its frequency.  Zero-beating a strong signal may help you hear a weaker one.  Tables 1 and 2 show how this works for USB and LSB respectively.  They indicate the heterodyne tone you will hear as you tune towards or away from each signal.

The negative value tones in the tables may not be heard if you are using a radio with selectable sideband (SSB).  If your radio has a traditional BFO, you will hear a tone at either side of zero beat.  In the tables, interpret the negative numbers for their absolute value, for example, |-100 Hz| = 100 Hz.

As part of the challenge for the 7508 kHz cluster, you may have to contend with interference from WRNO, 7505 kHz.  When you finish this challenge, try it again on the 10781 kHz cluster.

Good DXing.

Music is the universal shortwave language

Greetings as always to all the SWLing Post community, we are now ready to spill the beans on what we have to offer on the shortwave spectrum this week. Be ready for some space business and more about things that run on rails.

Firstly on Saturday 7th June 2025 at 1100 hrs UTC on 6160 kHz and then again on Sunday 8th June 2025 at 0900/1300 hrs UTC on 6160 kHz and at 2000 UTC on 3975 kHz and 6160 kHz (via the services of Shortwave Gold) we bring you the sounds of outer space with Starship Skybird.

Orbiting the ionosphere the skyship will bring you lots of intergalactic musical goodness, the sounds of distant planets, atmospherics and a whole lot more. Start the countdown to next weekend when you can strap yourself in for a trip of a lifetime. Tune in, make yourself a cosmic cocktail if that’s your thing and enjoy the sounds of space.

On Wednesday 11th May 2025 via WRMI  at 0200 UTC we depart again on a “locomotive journey across the ionosphere” with another episode of CTRN. We are back on the rails to present an hour of train tunes, class rail timetabling tales and memories of train stations that once were. Please tune in, mind the doors and enjoy the ride. Please make sure you present your Railcard alongside your rail ticket if you are expecting a shortwave discount.

More on Starship Skybird here:

For more information on all our shows, please write to imaginarystations@gmail.com and check out our old shows at our Mixcoud page here.

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