Would Sox games be on 93.7 HD signal?

Dan.Strassberg dan.strassberg@att.net
Fri Mar 12 11:36:12 EST 2010


I knew nearly all of that--and I do not understand how what I wrote is
in any way contradictory to it. That is, in the iBiquity FM-band
system, since the digital signals share the bandwidth and power
allocated to digital, only a station that has only one digital channel
(the analog-channel simulcast) could devote as much as 10% of the
analog-channel power to a single digital channel. But for the purposes
of my message, so what? The point is that, unless the Insignia
receiver was not meant to demodulate analog (and I believe that it can
demodulate analog), it is BOUND to be more than senstive enough to
pick up WBOQ's analog signal in Nelson's workplace in (I think) N
Reading.

-----
Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "Sid Schweiger" <sid@wrko.com>
To: <boston-radio-interest@rolinin.bostonradio.org>
Sent: Friday, March 12, 2010 11:07 AM
Subject: RE: Would Sox games be on 93.7 HD signal?


"if it can tune in HD3 channels, which operate at no more than 10% of
the station's full power..."

Not so.  You need to get your head out of analog when talking about
HD.

HD carriers are transmitted at a fixed data rate, and on FM-HD that
data rate is subdivided among however many audio channels the station
wishes to transmit.  For example, in hybrid mode (meaning,
transmitting analog along with the digital), the maximum data rate the
iBiquity spec calls for is 150kBps.  That data rate can be subdivided
into multiple channels but is a single stream of data at a constant
power output (for the most part, FM HD carriers are run at 1% of the
analog power level, equivalent to 20dB below analog carrier level,
although some stations are now able to raise that to 4% [-14dBc] per a
recent FCC ruling).  Typically the largest piece of that total data
rate is reserved for the HD1, which is a simulcast of the analog
audio, but it's really up to the station how they want to subdivide
it.  Subject to change, Mike-FM (HD1) is using 48kbps, Funkytown (HD2)
is using 48kbps and the WEEI simulcast on HD3 is using 24kbps.

If analog broadcast is ever turned off, sometime in the distant
future, the iBiquity spec calls for a maximum data rate of 300kbps,
which is enough to support several high-quality channels as well as
surround sound.

Sid Schweiger
IT Manager, Entercom New England
20 Guest St / 3d Floor
Brighton MA  02135-2040



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