Category Archives: Recordings

Pirate Radio Recordings: Radio Gallifrey Intergalactic

Pirate Radio Recordings: Radio Casablanca

Thursday night, I received word from Richard Blaine at Radio Casablanca:

“We plan to be on the air tonight on 6940 kHz AM, starting sometime around 2300 UTC, and running until the plane to Lisbon has departed.”

So at 23:00 Zulu, I started recording…

Though the noise level was particularly high on the lower HF bands, and Casablanca’s signal wasn’t quite as strong as previous nights, I could still enjoy Blaine’s nostalgic mix of WWII era music through the static. What a treat.

You can listen to the full recording via the embedded player above, or simply click here to download the MP3.

Pavel’s 70s era recording of a German numbers station

3 Replies

I read this account Pavel posted on the Spooks reflector and asked if he would share his story on the SWLing Post. He kindly agreed.

Pavel writes:

“Inspired by a recent thread about a vintage number station, I searched my old tapes (I really [have a] LOT of them, hundreds of reels, mostly with music, but sometimes with other interesting things) and finally found a short snippet of a German number station transmission. There is neither a start nor end of the transmission, just a few 5-digit groups. It was recorded sometime between 1977 – 1980, at my cottage near Ceska Lipa, Czech Republic (but it was Czechoslovak Socialistic Republic [then]).

Reception was made on a Czechoslovak tube receiver “Barcarola” on a shortwave band with classic AM (of course this receiver was not capable of SSB or any other advanced modes) using a random wire (about 10 m) antenna.

A recording was made on the B400 Czechoslovak tape recorder using a Scotch 220 magnetic tape (exactly the one which is in the picture), speed 9.53 cm/s. Import to the digital domain was performed using the Audacity open source sound recording and processing software, without any artificial filtering or other DSP techniques.

As you can hear, it was perfect, clear readability:

I know that because the recording is incomplete, it has just a low value as such, but maybe it can at least demonstrate, which kind of equipment was obvious at this time and that it was possible to use it for activities like SW listening and number station (at least the strong ones) monitoring.

I’m curious whether somebody will identify the station.

With regards,
Pavel

Pavel’s Barcarola was similar to this model (Photo source: http://www.oldradio.cz/)

What really amazes me is the fidelity of Pavel’s recording. Though the transmitter might have been relatively local, there is certainly something to be said for analog equipment–both Pavel’s Barcarola receiver and his B400 recorder.

I actually collect and maintain more tube receivers than solid state. While their sensitivity and selectivity isn’t always on par with modern receivers, their warm audio fidelity makes up for it.

If you can identify Pavel’s numbers station recording, please comment.

Hearing the speed of light: DX double echo

4 Replies

ionosphere-earth-radio-waves Two weeks ago, at the W4DXCC conference in Tennessee, I met Lyle Juroff (K9FIK). Not only did I find that Lyle and I had many radio interests in common, but he also told me a story about hearing, recording and analyzing a double echo on the HF bands. I asked if he would explain in an email and include the recording so that I could share it on the SWLing Post. He kindly agreed!

Lyle writes:

I worked a DX station [9A1A] on 10 meters this past spring. As the band improved, I heard an echo develop on his signal and guessed it might be long path so I began recording the audio. I then began to hear a double echo and looked at the waveform on AUDACITY. The timing marks on AUDACITY indicated 140 milliseconds between echos.

I went to Wolfram Alfa, one of my go-to sights for things I can’t remember, and looked up the earth circumference. It not only gave me the distance but also the time to travel it at the speed of light, 133 milliseconds. Not sure if everyone working DX has heard this sort of thing, I played the recording at the next East Tennessee DX Association meeting. Nobody said they had heard that kind of double echo.

Click here to download an mp3 of Lyle’s recording or simply listen via the embedded player below (note that the second recording is .WAV format):

Have you heard a double echo this profound? Please comment.

Many thanks to Lyle (K9FIK) for sharing his story!

Shortwave Radio Recordings: The Mighty KBC

Shortwave Radio Recordings: Radio Progreso

Shortwave Radio Recordings: Radio Australia

1 Reply

Like most Friday mornings, yesterday at 11:00 UTC, I tuned to 9,580 kHz to listen to Radio Australia news and ABC National’s technology program Download This Show.

While the signal out of Shepparton, Australia was as strong as ever, I heard adjacent interference from China Radio International.

Indeed, looking my WinRadio Excalibur‘s spectrum display (see image on right), you can see that CRI’s signal on 9,570 kHz was actually producing noise 15 kHz on either side of their AM carrier (for a total bandwidth of 30 kHz!). Radio Australia’s signal was much cleaner, sticking to their allotted 10 kHz bandwidth limit.

The recording of Radio Australia was still quite good, despite the interference, because I was able to run the Excalibur’s AM sync detector locked on the (less noisy) upper side band.

Click here to download the recording as an MP3, or simply listen via the embedded player below: