From: jeh@cmkrnl.com
Newsgroups: rec.audio
Subject: Re: digital radio
Date: 10 Jan 93 08:57:21 GMT
Organization: Kernel Mode Consulting, San Diego, CA

In article <58510@dime.cs.umass.edu>, oliver@smectos.gang.umass.edu 
(David Oliver) writes:
> Can anyone point me to information on "digital radio".  A (TV) cable company
> in my region is offering a 19-channel "digital radio" subscription, but the
> customer service types have NO technical information?

The 19-channel version sounds like "Digital Cable Radio".  In my area at least
there are actually 24 channels; the extra five are used for stereo sound from
MTV, HBO, etc., so you can hear those services' sound in stereo even if you
don't have a stereo TV or VCR.

Anyway, re DCR:  These 24 channels (actually 48 channels -- it's stereo) are
digitized, compressed, and put on a carrier that's within the passband of the
CATV system.  I don't know the compression ratio, nor whether it's "lossy" or
not, nor how much bandwidth the signal takes.  The cable company installs a
DCR "tuner" in your home.  This tunes to the DCR carrier and lets you select
one of the 24 channels.  Line-level outputs from this "tuner" go to an unused
pair of "aux" inputs on your stereo receiver, preamp, or whatever.  

The digital signal is *not* available for you to feed into a DAT deck or 
whatever.  (There is a three-pin connector on the back of the "tuner", 
labelled "data output" and described as "for future use with data services"
in the manual, but this does not appear to do anything at present.)  

You can of course record the analog signal just as you would from a real
tuner.  However this is not a good way to build a tape library of songs; most
of the time, the selections are crossfaded, so that even on a piece that 
doesn't normally end with a fade-out, it does on DCR, and the intro of the
next selection is faded in on top of the other's fadeout.  Ok for background
listening but a bummer if you care about the integrity of the music. 

There are no deejays.  If you want to know the title of something, DCR has an
800 number you can call.  You punch in the channel number on your TT phone, and
the machine reads you the title, artist, and label of the current and the two
previous selections.  They also have an 800 number (maybe the same one) which
lets you order the CD from which the current selection is taken.  (This btw is
via a deal with Tower Records.) 

The box is built by Jerrold and comes with its own remote.  The remote will 
also control at least some Jerrold CATV boxes.  

There is a similar service called DMX.  It has more channels, has a coax 
digital output jack on the back of the "tuner" in addition to the line-level
analog outs, and offers a remote with an LCD display that automatically 
displays the current selection info.  

Someone is sure to ask "how good is the signal".  I have my DCR box on my 
office system, which isn't a good setup for critical listening.  Put it this
way -- it sounds no worse than a typical run-of-the-mill CD player or FM tuner.

	--- Jamie Hanrahan, Kernel Mode Consulting, San Diego CA
Internet:  jeh@cmkrnl.com, hanrahan@eisner.decus.org, or jeh@crash.cts.com
Uucp:  ...{crash,eisner,uunet}!cmkrnl!jeh
From: Matt.Ion@p106.f7040.n153.z1.ship.wimsey.bc.ca (Matt Ion)
Sender: UUCP@ship.wimsey.bc.ca