Wednesday, August 28, 2019

FCC petitioned to open up 45 to 50 MHz for DRM+ broadcasts in the USA

Currently most of the terrestrial radio stations in the USA broadcast either on the AM band from 540 to 1700 kHz or on the FM band from 88 to 108 MHz. At the end of September 2018, the FCC announced that there were 4,464 stations on AM and 10,867 stations on FM [1].

Due the crowded nature of the existing bands, it has been hard to introduce new digital radio formats.

DRM or Digital Radio Mondiale is a digital format designed to replace existing AM transmissions with clearer audio and with just 20% of the power. DRM+ is the format for VHF.

WRNJ Radio co-owner Larry Tighe has now filed a petition for rulemaking with the FCC, asking that the 45 MHz to 50 MHz band on the VHF spectrum be reallocated for DRM+ transmissions.

In a statement, Tighe said... “The 45–50 MHz band was allocated to two-way radio users in business and government, who have since migrated to higher bandwidths where they can use handsets with smaller antennas. As a result, this spectrum is extremely quiet right now. WRNJ monitored this bandwidth for an extended period of time, and heard very few distant signals.”

“There were 660 TV stations between Channels 2 and 7 before the transition to UHF for HDTV. There are now only approximately 60 TV stations in the USA on those old VHF channels. There is plenty of spectrum to share with a new service, i.e., DRM+ or any modulation, if the FCC really wanted to move AMs.”

Even though the DRM standard has been around for over a decade, it is only recently that it has begun to make serious inroads to the broadcasting scene with India, China and Russia showing an interest. One of the current problems is the high cost of DRM receivers which is prohibitive to consumers in developing countries.

Obviously if the USA opted for a new DRM+ allocation, it would give the format a huge boost. If it turned out to be the 45 to 50 MHz allocation then it raises the possibility of long distance reception by means of Sporadic-E during the summer months or via F2 propagation around the peak of the sunspot cycle.

More info in the links below.

1) FCC stats for the number of AM and FM stations at the end of Sept 2018
3) Previous post - Russia proposes to use DRM on 65.9-74.0 MHz


ChrisOD121 said...

I also receive Radio World and always find interesting articles that I wouldn't have likely found elsewhere. A fine publication to keep abreast of new advancements.
I'm curious to see what the general response will be to the FCC petition to expand for DMR.

73 Chris O'Donnell KD2OBV

gccradioscience said...

Actually it needs to be 44 MHz to 49 MHz and reserve the rest for 49 to 50 MHz for 49 MHz walkie talkies and baby monitors. I mean the entire cordless 44 to 49 MHz phone band needs to be reserved for these DRM+ transmissions.

Mike N7MSD said...

Looks like I'm not the only one reading this in '21 (as of November, 7 experimental 8m USA licenses!). 44(5) to 50 MHz is used for more than just commercial. Its heavily used by the forest (dis-)service in California, for example, as no other band works as well in heavily forested canyons where you can't build anything because they turned all the mountain peaks into people-excluding wildernesses.

OTOH, his point about TV-2 thru 6 is dead on! I've been thinking for a long while that extending the FM band down to 64 MHz (as in Japan and much of former USSR) might be a great idea and making it all digital (DRM or the FCC's paid-for HDRadio).

I can even wish for a hole so we Region-2 hams can have a 4m band...I can dream, right?