On Oct 16, 3:07*pm, John Higdon wrote:
In article ,

*dave wrote:
There's no need for a separate tower. *Depending on the linearity and
headroom of the transmitter plant you could conceivably get by with just
a new exciter and new monitor.

That's a misconception. All pre-IBOC analog transmitters are non-linear
by design for efficiency reasons. They cannot pass an IBOC digital
signal, which consists of multiple carriers. A specially-designed linear
transmitter must be used.

I can see from reading these threads that many people are under the
impression that IBOC is nothing more than some sort of subcarrier
superimposed on the main channel. Unless the station is using a combo
analog/IBOC transmitter, the outputs of both analog and IBOC transmitter
must be combined by a device that discards 90% of the IBOC signal and
10% of the analog signal. All of that stuff costs money, as does the
increased air conditioning requirement, and power (particularly that
which is burned off as heat). In many installations (and I've seen
dozens...I wonder how many of our pontificators have even seen one), the
IBOC and analog transmitter sit side by side...and they're about the
same physical size.

My point is, adding IBOC to a station is far more complex and costly
than putting some 4-unit device in the rack and hooking it up. A "new
exciter" doesn't do it.

Oh, and don't forget the studio, the new digital STL, monitoring
equipment, and the fact that HD equipment currently in the field is
notoriously unreliable. Fortunately, most stations don't care that much
because their three HD listeners don't phone in to complain.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last

"Road-Testing the FMeXtra"

"In summary, FMeXtra is an economical and quick way for an FM station
to add additional programming channels and to begin digital
broadcasting. The system, which caught the attention of many
attendees, requires the purchase of an $8,900 encoder that can be
installed in less than an hour’s time, on average. There are no
licensing fees to use the FMeXtra system."

http://www.rwonline.com/article/276

"FMeXtra: Another On-Channel Solution"

"Eventually DRE asked the NRSC to reactivate the DAB subcommittee.
Early on, we saw that IBOC was going nowhere as long as there were
multiple proponents, and even in the best estimates, it would be many
years before there would be any return on investment. So we decided to
license our patent portfolio for use in IBOC to USA Digital Radio,
which eventually merged with Lucent’s IBOC group to form Ibiquity. We
are an Ibiquity shareholder... There is no significant difference in
spectrum occupancy between the 'extended hybrid' mode of IBOC today
and these earlier systems, which were deemed by the NRSC and others to
be incompatible with the host analog FM signal."

http://www.bext.com/RW/RWFMeXtraDec05.pdf

Makes one wonder, why FMeXtra was never used, but there seems to be
some illegal, anti-competitive issues with the iBiquity/DRE/Vucast
relationships.

"HD Radio Farce" wrote in message
...
On Oct 16, 3:07 pm, John Higdon wrote:
In article ,

dave wrote:
There's no need for a separate tower. Depending on the linearity and
headroom of the transmitter plant you could conceivably get by with just
a new exciter and new monitor.

That's a misconception. All pre-IBOC analog transmitters are non-linear
by design for efficiency reasons. They cannot pass an IBOC digital
signal, which consists of multiple carriers. A specially-designed linear
transmitter must be used.

I can see from reading these threads that many people are under the
impression that IBOC is nothing more than some sort of subcarrier
superimposed on the main channel. Unless the station is using a combo
analog/IBOC transmitter, the outputs of both analog and IBOC transmitter
must be combined by a device that discards 90% of the IBOC signal and
10% of the analog signal. All of that stuff costs money, as does the
increased air conditioning requirement, and power (particularly that
which is burned off as heat). In many installations (and I've seen
dozens...I wonder how many of our pontificators have even seen one), the
IBOC and analog transmitter sit side by side...and they're about the
same physical size.

My point is, adding IBOC to a station is far more complex and costly
than putting some 4-unit device in the rack and hooking it up. A "new
exciter" doesn't do it.

Oh, and don't forget the studio, the new digital STL, monitoring
equipment, and the fact that HD equipment currently in the field is
notoriously unreliable. Fortunately, most stations don't care that much
because their three HD listeners don't phone in to complain.

--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last

"Road-Testing the FMeXtra"

"In summary, FMeXtra is

http://www.rwonlidne.com/article/276

"FMeXtra: Another On-Channel Solution"

"Eventually DRE asked the NRSC to reactivate \\\


Another cut/paste by the HD nut.