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Great tour of that tower site, and a nice analysis of the requirements of transmitting both analogue and digital signals. For international readers, the digital

Great tour of that tower site, and a nice analysis of the requirements of transmitting both analogue and digital signals. For international readers, the digital radio standard of North America is the completely proprietary HD Radio (Hybrid Digital) IBOC (In-Band-On-Channel) system owned by DTS (nee iBiquity). The DAB system used outside of North America is incompatible. Automobiles built for the North American market now tend to come with HD Radio reception as standard equipment. As a proprietary system, HD Radio involves costs that can be prohibitive to small broadcasters. I do not know of any attempts to reverse-engineer the HD Radio system, nor am I qualified to guess at the workload involved, but an open license alternative is a nice dream that would enable a huge quality and capability improvement for even the smallest radio stations.

gorkish 4y ago
Here is a gnuradio module and some flowgraphs for transmitting NRSC-5 (HD Radio). https://github.com/argilo/gr-nrsc5 https://github.com/argilo/gr-nrsc5 A lot of the ibiquity patents are expiring this year or have already expired as well. I haven't been following the patent situation on this as closely as I used to, but needless to say I will be very excited when they all finally expire. Digital radio would have been awesome had it become pervasive in the late 90's when it should have.
geerlingguy 4y ago
For receivers at least, you can use some open source software to decode HD radio using an SDR, but the market for open source transmitter software is almost infinitesimally smaller. Plus it would be much easier to find and punish a station transmitting HD without a license. I know my Dad has a lot of experience on both sides of the licensing (both large radio conglomerates and smaller independent broadcasters) and I think having a discussion on the history and implementation of HD Radio in the US could make a good follow-up video at some point.
- cf100clunk 4y ago
  > it would be much easier to find and punish a station transmitting HD without a license If I'm understanding you, a clean sheet implementation of "HD Radio-compatible" digital broadcasting using open source and open hardware techniques over a federally licensed station would contravene the proprietary system's license?
  - geerlingguy 4y ago
    Unfortunately proving that nothing is infringing on whatever patents Ibiquity created would likely be difficult and/or expensive, and since most indie broadcasters are still happy to just broadcast analog-only for the time being, there's not a lot of will to fight for it.

gorkish 4y ago

Here is a gnuradio module and some flowgraphs for transmitting NRSC-5 (HD Radio). https://github.com/argilo/gr-nrsc5 https://github.com/argilo/gr-nrsc5 A lot of the ibiquity patents are expiring this year or have already expired as well. I haven't been following the patent situation on this as closely as I used to, but needless to say I will be very excited when they all finally expire. Digital radio would have been awesome had it become pervasive in the late 90's when it should have.

geerlingguy 4y ago

For receivers at least, you can use some open source software to decode HD radio using an SDR, but the market for open source transmitter software is almost infinitesimally smaller. Plus it would be much easier to find and punish a station transmitting HD without a license. I know my Dad has a lot of experience on both sides of the licensing (both large radio conglomerates and smaller independent broadcasters) and I think having a discussion on the history and implementation of HD Radio in the US could make a good follow-up video at some point.

cf100clunk 4y ago
> it would be much easier to find and punish a station transmitting HD without a license If I'm understanding you, a clean sheet implementation of "HD Radio-compatible" digital broadcasting using open source and open hardware techniques over a federally licensed station would contravene the proprietary system's license?
- geerlingguy 4y ago
  Unfortunately proving that nothing is infringing on whatever patents Ibiquity created would likely be difficult and/or expensive, and since most indie broadcasters are still happy to just broadcast analog-only for the time being, there's not a lot of will to fight for it.