Unraveling the Puzzle: When HD1 Drops But HD2 Doesn't
Fully Modulated
Ever faced a technical problem that defied conventional wisdom? In our latest deep-dive, we unravel a perplexing HD radio mystery that had us questioning everything we thought we knew about digital transmission.
Our HD1 signal kept dropping out randomly for fractions of seconds while HD2 played flawlessly—a contradiction that shouldn't happen if the issue was with the exciter or transport stream. We meticulously examined every component: the Nautel NV30 transmitter, HD multicast units, Omnia 9 processor, even the Justin 808 time alignment system. Everything checked out perfectly with no errors in logs, yet the problem persisted.
The breakthrough came when we discovered our monitoring equipment was giving contradictory information. The Inovonics 632 receivers consistently showed dropouts while the newer 551 mod monitors worked flawlessly. After consulting with colleagues, we uncovered the truth: the 632 tuners had a known flaw the manufacturer never publicly acknowledged. Meanwhile, HD2's natural advantage of a larger buffer (around 40 seconds in MP1 mode) provided greater resilience against minor data issues.
This experience highlights a frustrating reality for US broadcasters—we're locked into proprietary HD radio technology when other countries enjoy open digital standards with multiple competing manufacturers driving innovation and affordability. Norway transitioned to fully digital radio back in 2017, while we're still troubleshooting proprietary equipment quirks.
What HD radio equipment challenges have you faced? Have recommendations for reliable monitoring gear? Text us using the link in the show notes and share your experiences!
📚 Learn more:
Learn more about HD Radio: https://en.wikipedia.org/wiki/HD_Radio
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Fully Modulated is an independent podcast and website, not affiliated with or endorsed by any station, media company, or network. All opinions are solely my own.
