Category Archives: Digital Modes

PantronX Titus II DRM receiver update via Wavescan

Many thanks to SWLing Post contributor, Richard Langley, who writes:

There was a segment on the latest episode of AWR’s Wavescan (9 April 2017) about the Titus II DRM receiver recorded during the recent HFCC meeting in Jordan. In it, it was stated that the shipment of the first 1500 units was expected at the end of March or by the first half of April. Included some discussion of added shielding to prevent digital noise and the high-sensitivity of the receiver compared to other DRM units. Streaming and download of the Wavescan episode is available here:

http://awr.org/program/engmi_wav-2/

 Many thanks for the tip, Richard!

All India Radio investing heavily in DRM tranmitters

All India Radio (AIR) Headquarters in Dehli, India. Photo: Wikimedia Commons

Many thanks to SWLing Post reader, Pradip, who shares the following story from Radio and Music Biz online:

AIR has acquired 37 DRM transmitters, in talks to get cheaper radio sets

NEW DELHI: All India Radio (AIR) has introduced digital radio technology in the AIR Network by installing new state of the art Digital Radio Mondiale (DRM) Technology transmitters by replacing old outlived 37 Medium Wave/ Short Wave transmitters.

Minister of State for Information and Broadcasting Rajyavardhan Rathore told Parliament however that the provisions contained in Policy Guidelines on expansion of FM Radio broadcasting services through private agencies (Phase-III) do not provide for private FM broadcasters to adopt digital radio technology.

He said Digital Radio allows significant improvements in service reliability, audio quality, more radio services and higher efficiency.

The new AIR transmitters include 35 new state of art technology Medium Wave (MW)/ DRM transmitters as a replacement of old technology valve based MW transmitters. Additionally, two new state of the art technology Short Wave (SW) DRM transmitters have been approved for installation as a replacement of old SW transmitters.[…]

Continue reading at RadioAndMusic.com.

ISS SSTV: Receiving images from space

(Source: Southgate ARC)

Slow-scan television (SSTV) transmissions are planned from the International Space Station (ISS) on February 13-14, 2017

The SSTV images will be transmitted as part of the MAI-75 Experiment on 145.800 MHz FM using the Kenwood TM-D710 transceiver located in the Russian ISS Service module. It is thought they may use the PD-180 SSTV format.

The MAI-75 activities have been scheduled for the Russian crew on Monday, February 13 from 09:25-18:00 GMT and Tuesday, February 14 from 11:25-16:30 GMT.

Note the ISS transmissions on 145.800 MHz FM use the 5 kHz deviation standard rather than the narrow 2.5 kHz used in Europe. If your transceiver has selectable FM filters try the wider filter.

The ISS Fan Club website will show you when the space station is in range http://www.issfanclub.com/

ISS SSTV information and links at
https://amsat-uk.org/beginners/iss-sstv/

ARISS-SSTV Images
http://ariss-sstv.blogspot.co.uk/

Listen to the ISS when it is over Russia with the R4UAB WebSDR
http://websdr.r4uab.ru/

Listen to the ISS when in range of London with the SUWS WebSDR
http://websdr.suws.org.uk/

If you receive a full or partial picture from the Space Station your Local Newspaper may like to know
http://www.southgatearc.org/news/2016/july/now-is-a-great-time-to-get-ham-radio-publicity.htm

RadioWorld: Radio Pakistan Begins DRM+ Transition

(Source: RadioWorld via Dan Robinson)

The move from AM and FM transmitters to DRM+ technology is currently underway in Pakistan, according to a recent report from Radio Pakistan.

With DRM technology, Radio Pakistan will be able to air three channels from a single transmitter, as well as provide listeners with access to text services.[…]

Read full article at Radio World online.

Looking at HF OTH RADAR

Many thanks to SWLing Post contributor, Trevor, who shares this link to a blog post from Daniel Estevez describing the characteristics of HF OTH RADAR:

Most amateur operators are familiar with over-the-horizon radars in the HF bands. They sometimes pop up in the Amateur bands, rendering several tens of kilohertzs unusable. Inspired by Balint Seeber’s talk in GRCon16, I’ve decided to learn more about radars. Here I look at a typical OTH radar, presumably of Russian origin. It was recorded at my station around 20:00UTC on 8 December at a frequency around 6860kHz. This radar sometimes appears inside the 40m Amateur band as well.

Above this post you can see a waterfall plot of the radar signal. It’s the wide red signal. It is 15kHz wide and pretty strong, but severely affected by frequency-selective fading. Looking at the IQ recording in Audacity, it is clear that the radar uses pulses with a 50Hz repetition rate. This explains the characteristic sound of this radar when received with a conventional SSB radio. It sounds similar to AC hum (here in Europe, of course).

Continue reading on Daniel’s blog…