What's up with HD Radio

[Aaron Read]

Walkman/portable radios are not on anyone's radar.  I would not expect 
them for several years; the DSP chip that decodes the HD Radio algorithm 
is getting less power-hungry every year but so far it still sucks down 
waaaaay too many electrons to be used in portables.

There are also real questions amongst engineers about how exactly 
portable radios will be designed; the current crop of $5 walkmans & 
clock radios got that way by cutting a LOT of corners in the receiver 
filtering and technology...the result has been piss-poor tuners that can 
only receive the biggest signals out there.  A lot of radio engineers 
are still mad about that and are trying to prevent it from happening 
again with HD Radio.

Currently there's only one real option for non-car HD Radio and that's 
the Boston Acoustics Recepter HD Radio, which is $300.  There's a 
handful of VERY high-end surround receivers from Yamaha I think, they're 
in the $1500 range.   There's also car radios out there...Kenwood makes 
an add-on HD tuner that'll work with most any in-dash unit that can take 
a Sirius tuner.  Panasonic & Eclipse make "all in one" units.   Most 
retail outlets don't have radios yet but I know Tweeter Etc carries the 
BA Recepter HD, and that Radio Shack is supposed to start carrying the 
BA this summer.  Crutchfield is still probably your best bet for home or 
car radios, though.

By Christmas 2006 we are supposed to see several new home and car radios 
hit the market.  However, we've been told the same thing for Christmas 
2004 and 2005, too.  I'm getting cynical.

Multiple audio channels is officially called "Multicasting" and at the 
moment, the FCC is only authorizing two extra channels...meaning there's 
the HD-1 digital channel which, by the rules, MUST be the exact same 
audio as the analog channel (and must be time-sync'd).  In addition to 
the HD-1 is also an HD-2 and HD-3 channel.  Some stations are ready to 
deploy an HD-4 channel, and the system can theoretically support up to 
HD-7, but the FCC is not authorizing it yet.

The limiting factor is that all these extra channels must draw from the 
same pool of digital bandwidth: 96kbps.  So if you have an HD-2 channel, 
you have to split that 96kbps between two channels.  If you have an 
HD-3, that means it's split three ways.  And so on and so forth. 
Thanks to the HDC codec, even a 12kbps channel sounds better than you'd 
expect...but it's still pretty crunchy at that level.

There is technically nothing stopping AM stations from multicasting but 
the problem is the bandwidth.  AM only has 32kbps to play with and 
that's barely enough to deliver a quality stereo channel for HD-1. 
Whenever AM goes "all-digital" and the analog is gone, there will be 
more bandwidth and I think you'll see more multicasting there.

Another note, AM stations are only authorized to use their digital 
carriers between 6am and 6pm daily.  So there hasn't been a big rush to 
convert AM stations yet...in Boston I think only WBZ, WMKI and WBUR-AM 
(the latter being on the Cape but the digital is receivable along the 
Boston coast thanks to saltwater groundwave) are regularly using 
digital, although WILD-AM, WXKS-AM and WTAG have signed agreements and I 
believe they have systems in place, but I don't think they use 'em. 
Easy way to tell, though...just tune to their frequency during the day, 
then go one channel up or down.  If you hear a roar of white 
noise/static (on an analog radio) then they're running their HD digital 
carriers.

Most commercial stations have joined the "HD Radio Alliance" and are 
coordinating which formats they put on their HD-2 channels for at least 
the next few years as the technology rolls out and more radios become 
available.  You can find a good listing of stations & formats in your 
state here:

http://www.hdradio.com/stations_on_the_air.php

So far nobody is doing any of the three formats you wanted (Contemporary 
Christian music, Gaelic(Irish), and show tunes) although I do feel 
compelled to point out that several of the local college stations do 
have shows dedicated to all three of those genres (not at the same time, 
though :-)

-- 

--------------------------
Aaron Read
readaaron@friedbagels.com
www.friedbagels.com
Boston, MA 02176


1) No monthly fees--just the currently steep initial-purchase price.
2) No Walkman-style receivers yet. Not clear when these will arive. Few car
radios so far, but they are surely coming. Several tabletop or
boom-box-style models now.
3) The multiple channels are only for FM stations. AM is limited to a 
single channel per station. This doesn't HAVE to carry the same program 
as the analog channel, but there would be practical problems it if 
didn't. If the digital signal drops out (a common occurrence in car 
radios), the radio is supposed to drop back into the analog mode, where 
if everything is working as intended, the same program would continue 
uninterrupted. Running separate programs on the AM and digital signals 
would disable this feature, possibly rendering the digital reception 
unacceptable in all but the strongest-signal areas.

Somebody else will have to answer your question about what programming 
is available on the HD2 channels of Boston FMs. I don't think any of the
formats you listed is available. The most likely purveyor of CCM would 
be Salem (WEZE, WROL, WTTT). Since these are all AM stations, they 
couldn't have HD2 channels. Also Salem has stated that it is adopting a 
wait-and-see position on HD Radio--at least on its AM stations.

--
Dan Strassberg, dan.strassberg@att.net
eFax 707-215-6367