Brace yourselves for nighttime IBOC...

[DanStrassberg]

we engineering types call that the first harmonic.

THIS engineering type (and all of the engineering types with whom I'm acquanted) call 1600 kHz the SECOND harmonic of 800 kHz. Music types might call 1600 Hz the FIRST overtone of 800 Hz, but, in this case, I think the engineers have a much more sensible naming (OK, numbering) convention. Divide any frequency by the harmonic number and you get the fundamental frequency. No worries about, "do I subtract 1 from or add 1 to the harmonic number before I do the division?" As a general rule, though, my experience is that few groups are WORSE at picking names for most anything than engineers. We tend to base names on arcana that makes no sense to almost anybody.

 

[Neggy]

http://www.radioworld.com/pages/s.0049/t.7843.html

 

[webcastboy]

As I mentioned...the HD Radio Alliance's original stated term of existence was 18 - 24 months, starting in January of 2005. I have not heard any news about it ending, but logically it could have ended already.

To be a bit cynical, the Alliance's "no commercials on multicast channels" pledge was always pure marketing spin, anyways. Until the new rules go into effect on Sept.14th, all multicast channels are still considered an experiment service. Which means you need an STA to operate them and, by definition, they must be operated as a non-commercial service (just like stations between 88.1 and 91.9). So the Alliance was formed to make the best of it and market it as a way to encourage listeners to go buy HD Radio receivers and get no commercials...just like satellite radio. (so to speak)

I suppose they could've tried to solicit underwriting for the multicast channels, but the profit margin was no doubt deemed too low between the lack of radios in listeners' hands and the inherently lower dollar value of underwriting vs. advertising.

Also, since there were so few radios/listeners, they also agreed to coordinate their formats to avoid a format war on HD2...and by default increase programming diversity in a given market. Nice idea, although one wonders if that would be vulnerable to an anti-trust challenge if someone were inclined to sue over it. Nobody has been so inclined because, again, there's so few receivers out there that for the moment, it makes more sense to coordinate/collude than to not do so...and nobody's really making money off it yet, either.

Anyways, with the new rules going into effect, commercials will be allowed, which means (in theory) some actual money can be made off multicasting. So I seriously doubt the Alliance will be around much longer. Hell, I give it 50-50 odds that any sort of public announcement will even be made...it'll probably just quietly disappear.

 

[Eli Polonsky]

Kinda like the FM converter I (had in a '71 Pinto) recently found in MY dad's basement! ;D

There are still at least a couple of those oxidizing in my dad's basement as well.

In the mid-1980's, the opposite came out. There was a C-Quam AM Stereo converter which transmitted into your FM car stereo. I still have one. The output frequency was extremely unstable, and it drifted up and down at least .3 mHz depending on the temperature inside the car. It was very difficult to keep the FM stereo tuned into it as your heater came on in the winter or your A/C came on in the summer.

I find that plugging my AM Stereo Walkman into a new iPod-style FM transponder is stable, and works much better.