Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Many thanks to SWLing Post contributor, Fastburstradio23, who shares the following:
Beaming to you from the transmitter’s location, forget summer vacation, it’s time for summer school. Get your pencils sharpened and thinking caps on for the KMTS Summer Test (transmission)! Numbers, poetry, the science of strange tones, music and mountaineering are all part of the curriculum.
And if you are one of those cats who was too hip for school the first time around, we understand. We’ve been there! When you use one of our proprietary quantum radios passing is as easy and pleasant as a breeze blown in from a deserted tropical island. All the answers tp all the questions are right in some reality or timeline!
And after you’ve peaked out with us at the crown of KMTS, you can join us for a Mai Tai at the Tiki bar on top of the mountain as we go over the summer test results.
6070 kHz at 1700 UTC on Tuesday 27th July and 3rd August 2021.
Join me, Paul Walker, on WRMI Shortwave for “The LIVE Friday Night Request Show Dance Party Thingy” being relayed from NPR/community radio station KSKO 89.5 McGrath, Alaska.
It’ll take place Saturday July 10th 0300-0500UTC on 7780kHz to the east coast US and Western Europe, 7730kHz to the west coast US, Canada along with Hawaii, and the South Pacific (NZ, Aus, etc) and 4980kHz to the Caribbean and South America.
I’ll be taking phone calls with requests with a number given out during the show as it’s truly
LIVE. No station money was spent for this, It’s coming out of my pocket just to have something different up on shortwave for a few hours.
The music during the show could be ANYTHING from any genre and any year. It’s a combination of what *I* want to hear and what listeners request. I’ve had Judas Priest, Garth Brooks and Weird Al Yankovic back to back to back during the Friday night show before because they were all request in that order by 3 different listeners.
A note: 5850kHz/7570kHz is beamed towards Vancouver, 7330kHZ is beamed towards the US/Mexico border according to Jeff white which affords 7730 better coverage of the Pacific Ocean region countries than 5850 or 7570.
Many thanks to SWLing Post contributor, TomL, who shares the following guest post:
Recording Music on Shortwave Part 2 – Weak signal recovery
by TomL
The QRM noise cloud surrounding my condominium motivated my first foray into noise reduction software to find a little relief (Please refer to Part 1 posted here) using SDR recordings. I was able to use the freeware software Audacity to reduce some of that type of noise to tolerable levels on strong broadcasts. But what about non-condo noise, like out in the field??
NHK Japan
I took my trusty Loop On Ground antenna to the usual county park Forest Preserve which is relatively low in RF noise. I did some usual recording on 25 meters and poked around for something being captured by SDR Console. On 11910 kHz is NHK broadcasting daily from Koga, Japan. It is hearable at this location but is always an S7 or weaker signal despite its 300 KW of power no doubt due to being beamed away from the Midwest USA.
I recorded it using the SDR Console 10kHz bandwidth filter and created a separate noise recording from a nearby empty frequency. Here is the 2 minute portion of a Japanese music teacher. No noise reduction was applied:
I opened the noise and broadcast recordings in Audacity to see what I could do. Part 1 of my previously mentioned post details how I apply the Noise file. A big downside of using any kind of noise reduction software is that it is ridiculously easy to destroy the desirable characteristics of the original recording. Applying too much noise reduction, especially in the presence of constant, spiky lightning noises, will create both digital artifacts as well as very dull sounding results. So I used the Effect – Noise Reduction (NR) feature very carefully.
In this example, I used the Effect – Amplify feature on the one minute noise file. I applied just +1dB of Amplify to the whole file. Then I highlighted a 10 second section I thought was representative of the general background noise and chose Edit – Copy. Then, I opened the broadcast file, Pasted the 10 seconds of noise to the END of the file and highlighted just the 10 seconds of noise. Then I chose Effect – Noise Reduction – Get Noise Profile button. Amplifying the noise file by +1db does not sound like much but it seems to help according to my tests. Anymore than this and the Noise Profile would not recognize the noise without destroying the music.
I used the NR feature three times in succession using the following (NoiseReduction/Sensitivity/FrequencySmoothing) settings: Pass1 (3dB/0.79/1), Pass2 (2dB/1.28/1), Pass3 (1dB/2.05/0). Part of what I listened for was choosing the Residue circle and Preview button for any music or dialog that was being filtered out. If I heard something that came from the desired part of the recording in Residue, I knew that I hit the limit concerning the combination of Noise reduction and Sensitivity settings to engage. I used those Residue & Preview buttons over and over again with different settings to make sure I wasn’t getting rid of anything wanted. I also used the higher Noise reduction with lower Sensitivity to try to get rid of any momentary spiky type noise that is often associated with SWLing.
I messed around with a lot of test outputs of differing dB and Sensitivities and a lot seemed to depend on the strength of the broadcast signal compared to the noise. If the broadcast was weak, I could push the dB and Sensitivities a little harder. I also noted that with strong signal broadcasts, I could NOT use more than 1 dB of Noise reduction beyond a Sensitivity of about 0.85 without causing damage to the musical fidelity. This was a pretty low level of nuanced manipulation. Because of these minor level Audacity software settings, it dawned on me that it is very helpful to already be using a low-noise antenna design.
If the Sensitivity numbers look familiar, that is because I tried basing the series of Sensitivity on Fibonacci numbers 0.618 and 0.786. Don’t ask me why these type of numbers, they just ended up sounding better to me. I also needed a structured approach compared to just using random numbers! Probably any other similarly spaced Sensitivity numbers would work just fine, too.
Now if you really want to go crazy with this, add Pseudo Stereo to your favorite version of this file (also detailed in Part 1) and playback the file using VLC Media Player. That software has a couple of interesting features such as an Equalizer and a Stereo Widener. You may or may not like using these features but sometimes it helps with intelligibility of the voice and/or music [VLC will also let you right-click a folder of music and choose to play all it finds there without having to import each MP3 file into a special “Library” of music tracks where they bombard you with advertisements].
You can also turn on Windows Sonic for Headphones if you are using the Windows operating system. However, this can sometimes be too much audio manipulation for my tastes!
Here is the resulting NHK noise-reduced file with 9ms of delay with High & Low Filters:
Radio Thailand
Five days later I was out in the field again. This time I found Radio Thailand on 11920 kHz finishing up a Thai broadcast. It was a weaker S5 signal than the NHK example, so it would be a good test.
When I got home, I recorded the broadcast file at a Bandwidth filter of 8 kHz and using Slow AGC and the extra Noise file at 12kHz using Fast AGC. In a previous test I had noticed a very slight improvement in sound quality in the way noise seems to get out of the way quicker compared to Slow AGC (which is usually how I listen to shortwave broadcasters). I now try to remember to record the Noise file with Fast AGC.
Here is the original without any noise reduction:
This time the Noise file using Amplify +1dB did not help and I used it as-is for the 10 second Noise Profile. I then tried multiple passes of NR at higher and higher Sensitivities and ended up with these settings the best: Pass1 (1dB/0.79/0), Pass2 (1dB/1.27/0), Pass3 (1dB/2.05/0), Pass4 (1dB/3.33/0).
As a comparison, I tried recording only with SDR Console’s noise reduction NR1 set to 3dB and got this. I hear more noise and less of the music coming through:
Now for more crazy Pseudo Stereo to finish up the Audacity 4Pass version (nice Interval Signal of Buddhist bells ringing and station ID at the very end):
Summary
I do not understand why applying 3 or 4 separate 1dB Sensitivities of noise reduction is superior to just one Pass at 3dB Sensitivity (in Audacity) or the one 3dB noise reduction (in SDR Console). My guess is that doing 1 dB at different Sensitivities shaves off some spiky noise a little at a time, somehow allowing for more of the musical notes to poke through the noise cloud. Who knows but I can hear a difference in subtle musical notes and sharpness of voice and instruments. Probably the Fast AGC helps too.
Music is a Universal Language that we can share even when we don’t understand a word they are saying. And there is more music on the air than I thought. Some of these recordings sound surprisingly pleasing after noise reduction. The fake stereo is pumped through a CCrane FM Transmitter to a few radios in the home, or I can use the Beyerdynamic DT990 Pro headphones.
Many thanks to SWLing Post contributor, Pete Madtone, who shares the following: Just a quick one to report that the KDUB broadcast from earlier this year will be repeated on WRMIthis Sunday May 30th at 2300 UTC or Midnight UK time on 9395 kHz on the shortwaves. There’s a mix from One Deck Pete called “In Dub for KDUB” at 3.09 minutes in.
All the shows from the KMTS (or is it KTMS?) back catalogue are available on Mixcloud here if you’ve missed any of them. Tune in and dub out!
Many thanks to SWLing Post contributor, Bill Hemphill, who writes:
I ran across a reference to Radio Delta International Shortwave, a Hollands station on 6020 kHz. The reference was to a song that was recorded for them by Silvia Swart en het Radio Delta lied. Which (according to Google) translates to The Radio Delta Song. It’s on YouTube and I like the sound of it even thought I don’t know Dutch.
I learned that his store carries Pirate Music as well as the usual Dutch and other stuff a record store would normally carry. Now I understand her interest in radio.
One last song I found that she recorded with her group, The Greenlights:
Mijn opa is een zendpiraat
Which translate to: My grandfather is a radio pirate
Maybe one of the forum members can give us a quick translation/summary of the songs.
73
Bill Hemphill
WD9EQD
Thank you for sharing this, Bill! Any fans of Silvia Swart out there? Please comment!
Radio Waves: Stories Making Waves in the World of Radio
Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers. To that end: Welcome to the SWLing Post’sRadio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!
Many thanks to SWLing Post contributors Marty, Richard Cuff, David Iurescia, and Doug Katz for the following tips:
Canada’s international broadcast service from the English language team of Radio Canada International has come to an end.
RCI, (originally the International Service, CBC-IS) was initially created towards the end of the Second World War. The purpose was to broadcast news and information from home via shortwave to Canadian military personnel fighting in Europe. It also began providing reliable news and information to recently liberated countries and to Germans still in the war.
That reliable news and information was considered of great value during the subsequent Cold War years, as several more languages were added to the service such as Russian, Ukrainian, Czech, Hungarian and Polish. Other languages sections included as Brazilian Portuguese and Japanese. With 14 language sections in 1990, and some 200 staff, the full English and French newsroom provided news of interest and importance for each language section specifically targeted to each of the various broadcast regions around the world.
Following a major budget cut of some 80 per cent in 2012, the shortwave and satellite service was terminated along with the majority of staff including the newsroom and some language sections. In recent years, only Chinese (Mandarin), Arabic, and Spanish remained along with English and French. RCI was transformed into a much smaller internet-based operation consisting of three people per language section.
In December 2020, the domestic public broadcaster CBC / Radio-Canada announced that the English and French sections of RCI would close for good in May. In their place curated stories from the domestic English and French public broadcaster will be provided.
A manager will now oversee the staff of eight who will adapt curated stories from the CBC and Radio-Canada into Mandarin, Arabic, and Spanish, along with Punjabi and Tagalog.
An effort was and is being made by the RCI Action Committee to preserve and even expand the service which has garnered great support from a former prime minister, former diplomats and many academics, but the end date has come. This is the last entry by the RCI English section.
From the English Section consisting of Lynn, Marc, and Levon, faithful and long-time popular replacement Terry Haig, and recently also Vincenzo Morello, and the many others over the all those years, we thank you for having shared our stories over these many years.[…]
In 2018, David Goren, a radio producer and audio archivist, created the Brooklyn Pirate Radio Sound Map to collect the sounds of dozens of pirated broadcasts from across the borough. Pirate stations earn their name by hitching a ride on already licensed radio frequencies that typically cost commercial stations millions of dollars to acquire and set up. Nowhere in the country are there more pirate radio stations than in New York, where they provide a vital service to immigrant populations.
Goren estimates that New York has about a hundred pirate stations, transmitting from rooftops and attics to listeners seeking news from around the city and back home, as well as
entertainment and religious programming. The broadcasts bypass socioeconomic barriers and provide a means to seize control of the flow of information. But they are now at risk of extinction: Before Donald Trump left the White House, he signed the Pirate Act, which increased the authority of the Federal Communications Commission to fight pirate operations through mandatory sweeps in cities with high concentrations of pirate radio use. Pirate stations today face fines of up to two million dollars. “The people running these stations, they don’t have two million dollars,” Goren said. Broadcasters that don’t make it onto his sound map could be lost forever.
Inspired by espionage devices used during World War II and the Cold War, Shortwave transforms audio into clandestine operations of the past; Russian number stations, mysterious sounds transmitted by radio, and eerie sounds stored on early portable recorders.
Choose between 2 types of noise and interference, and control it with the Exposure parameter. Velocity and Focus control the amount of pitch stabilization. Shortwave will add an interesting emotional response and atmosphere to dry, simple sounds, or destroy a signal like no other fuzz pedal can.
Hand-made in Seattle, WA. Shortwave operates on a standard “Boss” style 9vdc power supply (not included), but can also run at 18vdc for additional headroom. True bypass switching. Included a limited-lifetime warranty.
Voyager 1 – one of two sibling NASA spacecraft launched 44 years ago and now the most distant human-made object in space – still works and zooms toward infinity.
As the craft toils, it has long since zipped past the edge of the solar system through the heliopause – the solar system’s border with interstellar space – into the interstellar medium. Now, its instruments have detected the constant drone of interstellar gas (plasma waves), according to Cornell-led research published May 10 in Nature Astronomy.
Examining data slowly sent back from more than 14 billion miles away, Stella Koch Ocker, a Cornell doctoral student in astronomy, has uncovered the emission. “It’s very faint and monotone, because it is in a narrow frequency bandwidth,” Ocker said. “We’re detecting the faint, persistent hum of interstellar gas.”
This work allows scientists to understand how the interstellar medium interacts with the solar wind, Ocker said, and how the protective bubble of the solar system’s heliosphere is shaped and modified by the interstellar environment.
Launched in September 1977, the Voyager 1 spacecraft flew by Jupiter in 1979 and then Saturn in late 1980. Travelling at about 38,000 mph, Voyager 1 crossed the heliopause in August 2012.
After entering interstellar space, the spacecraft’s Plasma Wave System detected perturbations in the gas. But, in between those eruptions – caused by our own roiling sun – researchers have uncovered a steady, persistent signature produced by the tenuous near-vacuum of space.
“The interstellar medium is like a quiet or gentle rain,” said senior author James Cordes, the George Feldstein Professor of Astronomy (A&S). “In the case of a solar outburst, it’s like detecting a lightning burst in a thunderstorm and then it’s back to a gentle rain.”
Ocker believes there is more low-level activity in the interstellar gas than scientists had previously thought, which allows researchers to track the spatial distribution of plasma – that is, when it’s not being perturbed by solar flares.[…]
