Category Archives: Recordings

Studio Recording of the KMTS Winter Test Transmission on December 17, 2020

If you missed the KMTS (or is that KTMS?) test broadcast on the 17th of December 2020, you’re in luck. I’ve just discovered a studio recording of the entire broadcast on Soundcloud, via a Post reader tip.

I’ve embedded a Soundcloud audio player below, but you can also listen via Soundcloud:

I’ll admit that this broadcast had a lot of listeners scratching their heads–a bit of a mystery. Reminded me, to some degree, of the Boards Of Canada pirate radio broadcasts some years ago, and the mystery surrounding a BoC album release. Also reminded me on one of my all-time favorite pirate radio stations: Radio Strange Outpost. But, of course, this wasn’t a pirate station.

I know this: I absolutely LOVE the KMTS test broadcast! What fun! Kudos to the producer (or producers)! I’ll add this to the Shortwave Radio Audio Archive. If anyone was able to make a full off-air recording of the broadcast, please contact me and I’ll add that along with the studio recording.

Yet another “Wacky Wake-Up Crew” recording

After posting recordings of 630 AM WAIZ’s “Wacky Wake-Up Crew” recently, a few readers asked for yet another recording, so here you go!

I made this recording yesterday morning (December, 16, 2020), starting around 5:30 EST with the Icom IC-705 connected to my homebrew NCPL antenna:

April’s collection of Japanese language WebSDR recordings for November 2020

Many thanks to SWLing Post contributor, April TimeLady, who shares her latest collection of Japanese language WebSDR recordings–this time, for November 2020.

Feel free to listen to her recordings via the clickable playlist below, or on her Archive.org page.

Thank you, April for once again uploading and sharing your recordings!

Click here for a link to this and all of April’s archived recordings.

David shares a recording of the RTE longwave interval signal

Many thanks to SWLing Post contributor, David Shannon, who writes:

Hi Thomas

A little treat for my fellow readers of your blog (is that the right word?). The RTE interval signal, a rendition of O’Donnell Abú (“O’Donnell Forever”), that is played at 0529 daily, apart from the weekend when it’s played at 0629 (even interval signals need a lie in) and received on longwave here in Scotland.

I know that longwave broadcasting is a very European thing with the exception of the likes of Mongolia (holy grail stuff for me) but it’s where my fascination for the bands started way back in 1978/9.

Sláinte mhaith gach duine
(Irish Gaelic for good health everyone)

That’s a beautiful interval signal, David. Thank you so much for sharing it with your fellow Post readers! There are few things in this world that make me feel more nostalgic than an off-air recording of an interval signal. Go Raibh Maith Agat!

Matt’s Monster Mediumwave Radio Selectivity Shootout!

Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), for sharing another brilliant audio comparison featuring benchmark portable radios:


Medium wave selectivity shootout

by Matt Blaze

I did another monster medium wave portable receiver comparison, this time with the aim of comparing receivers’ ability to deal with weak signals in the presence of strong adjacent channels.

Once again, I went up to the roof with eight MW portables with built-in antennas and recorded them simultaneously along with my “reference signal”, from an Icom R-9500 with an active loop on the roof. As before, I recorded a narrated stereo mix with the Icom on the left and the rotation of radios for a minute or two each on the right, but have “solo” tracks available for the full time for each radio. The nine receivers in the lineup this time included:

  • Icom R-9500 (with amplified Wellbrook loop antenna on roof)
  • Potomac Instruments FIM-41 Field Intensity Meter (my personal favorite)
  • Panasonic RF-2200
  • Sony IC-EX5MK2
  • C.Crane Radio 2E
  • Sangean PR-D4W
  • Sangean ATS-909X
  • Tecsun PL-990X
  • XHDATA D-808

I recorded two signals, one at night and one during the day.

Nighttime Signals

The first was at night: WWL New Orleans on 870 KHz. This signal is usually weak to medium strength here, but is a challenge for two reasons: first, it shares the frequency with Cuba’s Radio Reloj, and it is squeezed between two much higher strength signals: Toronto’s CJBC on 860, and NYC’s WCBS on 880. So you need a decent receiver and careful antenna orientation to receive it well here. That said, everything did pretty well, though you can see that some radios did better than others.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Daytime Signals

The second signal was during the day and was MUCH more marginal: WRJR Claremont, VA on 670 KHz. This was real challenge for any receiver and antenna. The signal was weak, and overshadowed by WCBM Baltimore on 680, a 50KW daytimer that is very strong here. (I’m not 100% sure that we were actually listening to WRJR – I never got an ID, but the station format and signal bearing was right). We can really hear some differences between the radios here.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Everything (except the Icom) was powered by batteries and used the internal MW wave antenna, oriented for best reception by ear (not just maximizing signal strength, but also nulling any interference). The loop for the Icom was similarly oriented for best intelligibility.

For audio nerds: The recording setup involved a lot of gear, but made it fairly easy to manage capturing so many inputs at once. The portable radios were all connected to a Sound Devices 788T recorder, with levels controlled by a CL-9 linear mixing board control surface. This both recorded the solo tracks for the portables as well as providing a rotating mix signal for each receiver that was sent to the next recorder in the chain, a Sound Devices 833. The 833 received the mix audio from the 788T, which went directly to the right channel. The left channel on the 833 got audio from a Lectrosonics 822 digital wireless receiver, which had the feed from the Icom R-9500 in the shack (via a Lectrosonics DBu transmitter). The center channel on the 833 for narration of the mix, which I did with a Coles 4104B noise-canceling ribbon mic. This let me record fairly clean audio in spite of a fairly noisy environment with some wind.

All the radio tracks were recorded directly off the radios’ audio line outputs, or, if no line out was available, from the speaker/headphone jack through a “direct box” interface. I tried to make the levels as close to equal as I could, but varied band conditions and different receiver AGC characteristics made it difficult to be completely consistent.

Making the recordings was pretty easy once it was set up, but it did involve a turning a lot of knobs and moving faders in real time. I must have looked like some kind of mad scientist DJ to my neighbors, some of whom looked at me oddly from their own roofs.

Happy Thanksgiving weekend!


Thank you, Matt, for another brilliant audio comparison! I appreciate the attention and care you put into setting up and performing these comparisons–not an easy task to say the least. That Potomac Instruments FIM-41 is an impressive machine!

By the way, I consider it a badge of honor when the neighbors look at me as if I’m a mad scientist. I’m willing to bet this wasn’t your first time! 🙂

Post readers: If you like this audio comparison, please check out Matt’s previous posts as well:

1979 ANARC Convention live recording featuring keynote by Rudy Espinal of Radio Clarin

Shortwave Radio Audio Archive contributor, Tom Gavaras, shares some of the most amazing off-air, studio, and personal recordings our archive.

Recently, he submitted a very unique recording. Tom notes:

Rudy Espinal of Radio Clarin (Dominican Republic) keynote speech at 1979 Association of North American Radio Clubs (ANARC) convention held in Minneapolis, Minnesota. Convention took place in June 1979.

In this recording, you’ll hear a number of familiar names (including an early shout-out to our friend Kim Elliott).

I was in elementary school at the time of this convention, so it’s amazing bit of audio time travel for me.

Do you recognize any names in this recording? Do you remember Radio Clarin? Did you attend the 1979 ANARC Convention?  Inquiring minds want to know! Please comment!

April’s collection of Japanese language WebSDR recordings for October 2020

Many thanks to SWLing Post contributor, April TimeLady, who writes:

In this email is a link to recordings I made from Japanese SDRs over the course of October 2020 and have uploaded to archive.org. This is the link:

https://archive.org/details/JPSDROCT2020

The original files are in .wav, archive.org converts them to mp3 and flac. Files with sas in them are supposed to be in stereo. There are many shortwave recordings in it, as well as mediumwave.

For anyone who is hunting IDs, Japanese radio stations definitely announce their full ID at 5 AM Japan Standard Time each day. On the top of the hour commercial radio stations ID. On Mondays between 1 and 2 AM (commonly given as between 25:00 and 26:00 Sundays on Japanese radio schedules) many Japanese radio stations go off the air for transmitter maintenance and give a very full, 5 minute long ID. I believe I have included one that I clipped for 1008 AM in Osaka in this month’s collection; 1008 AM, JONR is definitely in full AM stereo.

A good reference for Japanese AM radio call signs is on MWList at http://www.mwlist.org/mwlist_quick_and_easy.php?area=2

Thank you for reading this, and please take care.

Thank you, April for uploading and sharing your recordings! I’ve enjoyed browsing these each month!

Click here for a link to this and all of April’s archived recordings.