By SCOTT FYBUSH

The first HD2 transmission on an all-digital AM radio signal quietly took place as a test on Thursday, according to Dave Kolesar, who’s been at the helm of Hubbard Radio’s experiments with Xperi’s MA3 all-digital system on WWFD (820) in Frederick, Maryland.

Kolesar revealed the test during an interview from the WWFD site on This Week in Radio Tech. (Back in March, we also visited the site and talked to Dave and Mike Raide for our own interview on the Top of the Tower Podcast – and we need to get back!)

The test, which lasted about five hours, used 25 kbps as the data rate for the HD1, 12 kbps for the experimental HD2 and about 3 kbps for data services. Kolesar (who just received Radio World‘s engineer of the year award, too!) says it couldn’t be received on existing radios; while the code in almost all existing HD Radio receivers can receive the MA3 main channel WWFD has been using, it’s not configured for an HD2 in existing radios.

Future radios, however, might include the code for an HD2 – and in the meantime, could an MA3 HD2 feed a second format to an AM station’s second translator? There’s sure to be plenty of discussion on that topic. (And feel free to weigh in with questions in the comments below.)

Kolesar says a next test at WWFD will use 20 kbps for the HD1 (the same data rate WWFD was using for its entire HD signal when we visited in March, before a new transmitter and encoder were installed to double the data rate), with 17 kbps for HD2 and 3 kbps for data.

We’ll be following the tests closely. And in the meantime, that lovely scene of the WWFD towers appears in Tower Site Calendar 2020, just back from the printer and on sale now at the Fybush.com store!