Saturday, September 26, 2020

Details on Rádio Nacional da Amazônia DRM tests

With the recent excellent news coming out of Brazil, I took a few moments to contact our longtime DRM friend Rafael Diniz. He filled me in on some of the aspects of the upcoming DRM tests there:

Rafael, what is the current national status of DRM for digital broadcasting?

The digital radio discussion is stuck, mostly locked by the commercial broadcasters which publicity expressed against the digitization of the radio (citing, for example, the ongoing expenses of the broadcasters with the AM to FM migration, the crisis, and so on). Digital Radio seems a treat to the commercial broadcasting sector, but I will not elaborate more about it, as this discussion would take at least a 15 pages introduction.

 Can you tell us a little about the broadcast chain for this upcoming test? 

The broadcast chain will be a Brazilian BT Broadcast Transmitter 2.5kW HF tx, The exciter is a Digidia one, and the CS we'll experiment with different configurations, including Digidia and Fraunhofer options. The antenna is a huge HRS one beamed (with reflectors) to the north (good for US!), with between 16 and 20db of gain (Rodeador Park has many huge HRS antennas).

Will there be experiments similar to the recent work at KTWR using different parameters to see what works best? What about xHE-AAC?

We plan to use the best possible audio, which, if equipment permits, will be xHE-AAC audio and multimedia content. The idea is to also test 20kHz bandwidth, which will allow more than one audio program over the transmission, together with multimedia content.

 What will the content be?

Rádio Nacional da Amazônia content, the same of broadcast in 6,180 kHz and 11,780 kHz.

Is there any long term plan, or is this simply a feasibility test?

EBC is the process of purchase of two 100 kW DRM transmitters, to be delivered sometime in 2021 to really provide a steady digital reception even with the smallest battery powered receiver in all parts of the Amazon rainforest region. Concerning the long term - is the hope that this DRM transmission raise awareness of digital radio in the country and can change the minds of the commercial broadcasters about digital radio... and also save the MW band, which is getting empty - which is good and bad at the same time... with clear channels DRM nighttime reception can be fun again.

Thank you Rafael for your time and such great news. We look forward to more details and even more to signals making it to North America! Rádio Nacional da Amazônia is often heard here with great signal level and quality.