Tag Archives: Mark Fahey

SDR Spectrum to Radio: Can someone please make this device?

The venerable RF switch box from the 1970s/80s allowed game consoles and computers to use analog TVs as monitors.

As I’ve mentioned in the past, I actively record and index radio spectrum recordings via my various software defined receivers. Indeed, I have at least 50 TB of SDR spectrum recordings at the moment–and that number is growing!

I was just chatting with SWLing Post contributor, Mark Fahey, and a familiar topic came up: the idea of an RF switch box for radios.

The concept is a piece of hardware that re-modulates–converts digital spectrum data from a digital storage device back to analog RF– and injects a signal into a real tabletop radio.

As Mark described:

“This is just like early computers and Atari-like games consoles did to allow the “computer” to display on a lounge room TV. The games console tricked the TV into thinking it was tuned to a TV station on “Channel 1 (or whatever the console outputted the video to).”

Radio time travel machine!

How cool would it be to take a spectrum recording from 2008, play it through your Hallicrafters SX-100, Kenwood R-1000 or Alinco DX-R8T, and tune through the 31 meter band? You’d receive Radio Australia, Radio Bulgaria, Radio Netherlands Worldwide, Radio Canada International, Voice of Russia and many other broadcasters that are no longer on the air. Indeed, there’s a strong possibility you might uncover DX you didn’t catch when the recording was first made.

I’m enough of a radio geek to know that I would thoroughly enjoy travelling back in time once in a while with a classic radio.

Additionally, this device would make it much easier for museums to create kiosks where visitors could tune through recordings of, say, important events in history.

Can it be done?

I know the technology is out there.  In fact, if you’ve ever been to a large hamfest where Icom, Yaesu or Kenwood have a number of their transceivers “on the air”–so customers can try out transceiver features–they are using a device called a “radio time machine.”

Icom uses recorded IF instead of live antenna input so customers can experience “contest conditions” while evaluating a radio.

The Radio Time Machine injects recorded analog RF, from a HiFi VCR, into the antenna ports of a vendor’s various transceivers. The recordings are typically of a ham radio band during a contest–that way, the customer can get a sense of how well the rig would perform under crowded band conditions.

These devices have limitations: while their bandwidth is ample to tune through the CW or phone portion of a ham band, it’s much too narrow for most broadcast bands. They’re also fed the recording from an analog HiFi VCR.

The device Mark and I dream of would convert digital spectrum files–from a WinRadio, Perseus, Elad, SDRplay, Airspy or other SDR–into analog RF any radio with an external antenna port could tune.

SWLing Post readers: you’re a diverse and knowledgeable community–please comment if you know what it would take to develop such a device and how it could be done. Is this a dream or could it become reality?

North Korea now broadcasting in DRM

Many thanks to SWLing Post contributor, Mark Fahey, who writes:

A message to contacts in North Asia (Japan / Korea etc)…

North Korea is currently (right now 1430UTC) broadcasting in DRM format on 3560KHz. Listening to remote receivers in Japan I can see the signal is very strong in the Tokyo and Yokohama areas – I assume it will be strong in other parts of Japan as well. I have NOT been able to decode the DRM successfully, I have tried piping the audio to me here in my Australian location and demodulating it with a software DRM decoder – I just can’t get a lock on the signal. Do you have a DRM receiver – could you please try? If you do manage to receive the signal please don’t forget to record it!

I’m particularly interested to know if the transmissions are relays of KCBS Pyongyang, Pyongyang Pangsong or some other service. If you get a demodulated signal could you check to see if the program is parallel to KCBS Pyongyang on 2850KHz or Pyongyang Pangsong on 6400KHz.

I have a WinRadio Excalibur with DRM here in Australia, but the signal is very weak here – far too weak to lock.

Later, Mark shared the following video by “2010DFS” on YouTube:

Click here to view on YouTube.

Mark also notes that DRMNA.info is following this story very closely and suspects that the content server and or transmitter may be Chinese in origin:

NOTE: Same frequency and bitrate as the 2012 broadcasts so this may represent “Chinese assistance”. Can anyone confirm DRM equipment in Kujang?

20170902 Update: I have received anonymous details that indicate that at least the content server is of Chinese origin. Still no word on actual transmit location. Several other Japanese (and Terje in Japan) have successfully decoded these transmissions.

Click here to read full details at DRMNA.info.

Being a North Korean propaganda specialist, Mark added:

At the Freeman’s Reach monitoring station the bandwidth and microwave paths in are really being tested this afternoon with the full on activity.

All plans for the afternoon and evening now cancelled! YTN (South Korea) via Intelsat, KCTV Pyongyang via Thaicom, CNN International via Foxtel, CNN USA Domestic via Sling, Korean Central Radio and Pyongyang Pansong via KiwiSDRs – Busy!

All spectrum being captured, tonight the servers will be working hard, it will keep this place warm!

Post readers: please comment if you’re able to decode any of these North Korean DRM transmissions, and/or if you have further information about these DRM broadcasts from North Korea.

UPDATE: Mark has at least confirmed that the DRM signal is a relay of the KCBS Pyongyang national service (domestic) broadcast.

Mark records “Pyongyang’s 6 am wake up call”

This week, SWLing Post contributor, Mark Fahey, was featured in the NK News for his research in North Korea. While Mark has made a wide array of his work available through a media-rich (free) iBook, this particular article focuses on the “Morning Chorus” heard throughout Pyongyang in the early hours of the morning:

(Source: NK News)

Why does an eerie electronic ballad play across North Korea’s capital every morning?

It was early in the morning, but Mark Fahey had been awake for hours. A biomedical engineer turned North Korean propaganda expert, he had spent most of the night tinkering with a radio in his room at the Yanggakdo International Hotel, secretly recording the opening moments of Pyongyang FM Pangsong.

While he listened to the station’s typical offering of classical music and propaganda, another microphone and recorder were set up next to an open window to capture the sounds of the city as it roused itself awake. It was August 2011, and the sun hung low on the horizon. Fahey expected to pick up the sound of the dredging work taking place along the Taedong River.

Instead, he heard music.

“Pyongyang is deadly silent at night,” Fahey tells NK News. “If a lorry’s just passing through the city, you’re going to hear it. It’s so quiet. And at 6 am, you hear this kind of weird…” he hesitates. “It sounds like mind control music.”

Seeking an explanation, Fahey brought the tune up with his minder.

“They didn’t know what I was talking about,” he recalls, “but I don’t actually think that means they didn’t know what it was. They probably didn’t realize that I could hear it from where I was.”[…]

Click here to continue reading the full article at the NK News.

The NK News article is fascinating and also includes several more video clips from North Korea media.

Also, consider downloading Mark’s interactive iBook Behind The Curtain from the Apple store by clicking here.

KiwiSDR network updates include native HF FAX

Many thanks to SWLing Post contributor, Mark Fahey, who writes:

Lots happening with KiwiSDR – there are now over 130 live 0-30MHz fully controllable SDRs scatted around the world some in really interesting locations. Using Kiwi’s around the world is like being able to go on a exotic DXpedition any time.

Here (attached graphic) is a map of the current locations, you can see the live status of online receivers here:

http://rx.linkfanel.net

and as a list of receivers here:

http://kiwisdr.com/public/

KiwiSDRs now include HF Fax reception natively, just select Fax in the Extension menu, select the part of the world you are interested in and the Kiwi will tune the weather fax frequency and receive the weather fax all natively (no extra software needed) – too easy!

Lots more great things happening.

Here is the latest news…

http://www.kiwisdr.com/#id-31-may-17

Cheers,
Mark

Thank you for the update, Mark! I had no idea the KiwiSDR app had an HF Fax extension. After reading your message, I loaded a KiwiSDR session in Europe and used the Fax feature. It couldn’t have been easier. The screen grab (above) came from my first attempt.

The KiwiSDR network is truly amazing. I use it all the time–especially if there’s an important broadcast happening and I can’t easily receive it at home or while traveling. As an example, during the recent French elections, I listened to results roll in on France Inter mediumwave from a KiwiSDR in Italy. It felt like being there.

My one feature request would be that the KiwiSDR app include some form of native broadcast recording like the WebSDR at U Twente.

Many thanks for the update, Mark!

Click here to read about Mark’s KiwiSDR installation.

Would you like to host your own KiwiSDR?

The whole system only costs $299 US. The KiwiSDR site has a list of distributors around the world.

Amazon has units in stock at $299 US shipped.

I would have purchased a KiwiSDR ages ago–during their Kickstarter campaign–if I only had the Internet bandwidth at home to support it. My Internet speeds are likely lower than anyone else here in the SWLing Post community. One of the compromises living in a relatively remote spot with no RFI. 🙂

How to find the Pyongyang numbers station (V15) including an off-air recording

Many thanks to SWLing Post contributor, Mark Fahey (our resident North Korea specialist)  who shares the following comment regarding our recent post about the re-activation of the North Korean Numbers station:

The Pyongyang numbers (designated V15) have either become less regular or changed their schedule since March. Its been a few months since I have personally received them – but I also haven’t been specifically tuning in for them lately so maybe I have simply missed noticing a timing change.

If you want to find the North Korean numbers, they are read out in a block between songs within the regular programing of the Pyongyang Pangsong radio station.

The choice of music immediately before the number block seems to indicate which recipient agent the transmission is directed to.

For Agent 27 “We Will Go Together with a Song Of Joy” is played, whereas Agent 21’s song is “Spring of my Hometown.”

The announcements typically take between 5 to 10 minutes to read dependent on the number of digits passed. The transmission schedule is variable; in early 2017 the broadcast alternated with a cycle of one week on Thursday night at 12:45AM Pyongyang Time (1615 UTC) and the following week on Saturday night at 11:45PM Pyongyang Time (1515 UTC).??

Pyongyang Pangsong can be heard on these shortwave band frequencies (it is also on MF & FM on the Korean peninsular):

  • 3250 kHz, Pyongyang 100KW Transmitter
  • 3320 kHz, Pyongyang 50KW Transmitter
  • 6400 kHz, Kanggye 50KW Transmitter

Mark followed up this morning with a off-air recording of V15 on 3250kHz. Mark comments, “I will leave the decrypted message content to your imagination!”

Click here to download.

Mark: thank you for taking the time to write up this V15 tutorial and sharing this recording!