Armstrong Tower Could Be Test Site for DRM on Shortwave Bands

Turms Tech plans to use yagi-type antennas, generating an ERP of 10 kW on 9.65 and 15.45 MHz, to broadcast DRM to Europe and Middle East June 20, 2017

LOS ANGELES — In our e-newsletter, we cover all manner of digital transmissions of radio, including streaming/mobile, HD Radio, DAB and, though not as frequently, the other digital radio standard known as Digital Radio Mondiale.  Let’s get caught up on the DRM news front.

At the annual meeting of the National Association of Shortwave Broadcasters, the topic of DRM receivers was of great importance:

  • Jerome Hirigoyen spoke about three different receiver types: a portable, a dongle and a shipboard unit. A prototype of one of the solutions was available for inspection.
  • George Ross of Transworld Radio shared information on the current status of the PantronX Titus II receiver. He believes production units of this Android tablet-based solution available within a couple of weeks.
  • The Gospell GR-216 table top receiver was also mentioned.

Of interest in the U.S. is the recent application of Turms Tech LLC to broadcast DRM from New Jersey toward Europe and the Middle East. Specifically, they plan on using the Armstrong tower, just west and north of New York City, with yagi-type antennas, generating an ERP of 10 kW on 9.65 and 15.45 MHz.

From DRM news we learn that during May and June of 2017, experimental DRM transmissions were resumed by Brazilian Public Broadcaster (EBC) from the Rodeador Park, where the Rádio Nacional transmission facility is located. Different antennas and frequencies were tested, and reception reports from places more than 1000km away were received. The transmissions are being carried by Brazilian Digital Radio Association (ABRADIG) in partnership with EBC. The intention of these low power transmissions is to raise awareness of the DRM digital radio system for the broadcasters and the new government towards its adoption as a national standard and to enable permanent high-power DRM transmissions from EBC.

In a recent posting in our newsletter, we described a DRM test carried out on Batam island, adjacent to Singapore. More details of the test are now forthcoming. The existing FM transmitter is on 105.1 MHz and DRM was placed at 105.25 MHz. The current analog transmitter chosen for the demo has a power of 5kW, but 2.5 kW was used for simulcast mode (FM and DRM) with only 0.2KW of DRM power.

The DRM signal power was thus 11 dB below the analog FM. The mode used was DRM Mode E (DRM+), 4 QAM and the protection level PL-1. The content available during the demo was 2 audio services (16 kbit and 17.7 kbit/s) and Journaline service. For mobile reception, the predicted coverage area was calculated to be within 40 dBuV/m contour. 

“Both the indoor and mobile reception were excellent and no interference was noted to the neighboring FM stations at 105.1MHz and 105.5 MHz,” according to DRM news.

 

Receive regular news and technology updates. Sign up for our free newsletter here.

Comments