View Single Post
  #10   Report Post  
Old October 4th 07, 01:29 AM posted to rec.audio.tech,rec.audio.car,rec.radio.shortwave,ba.broadcast
Hein ten Horn Hein ten Horn is offline
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 48
Default DRM -Ain't- IBOC

wrote
On Oct 2, 6:17 pm, RHF wrote:

drm ain't iboc -and- iboc ain't drm ~ RHF


You are dumb. DRM has a hybrid digital/analog mode. See this manual,
page 20. Notice how the DRM sits "in-band on-channel" same as the HD
Radio works.
www.drm.org/pdfs/Broadcast_Manual.pdf

No, the manual does not state
"DRM has a hybrid digital/analog mode".
A simulcast is not necessarily hybrid.
I also cannot find any affirmation on your statement
Notice how the DRM sits "in-band on-channel".

RHF dumb?
Don't think so.
Take a good look on that page 20 of the manual.

[quote]
DRM supports a number of different simulcast options. Currently the
supported simulcast modes require the use of additional spectrum outside
an assigned 9 or 10 kHz channel (Multi-Channel or Multi-frequency
Simulcast, MCS). The DRM signal can be located in the next adjacent
upper or lower channel and can occupy a half or whole channel
depending on the bandwidth option chosen.
[unquote]

So far nothing about IBOC.
In general, a simulcast is a simultaneous transmission of the same
programme. Here, both transmissions are located in two adjacent
channels, the DRM transmitter operating with less power than the
analogue signal transmitter.

[quote]
(..) a satisfactory compromise can be obtained when the DRM power
level is around 14-16 dB below the adjacent analogue signal.
[unquote]

Unfortunately, operating on two adjacent frequencies (channels) may
give rise to interference problems. With IBOC no such problems
would occur, isn't it?
Now read the following about a possible DRM-future...

[quote]
In an ideal world it would also be possible to transmit both an analogue
and a digital signal within the same channel (9 or 10 kHz) so that the
analogue service could be received, without interference from the
digital signal, on any analogue receiver.
[unquote]

With only one transmission there would be no interference,
so in the real world anno 2007 interference may arise and
DRM is not IBOC.
The statement "DRM is not IBOC" is also apparent from
some other quotes from page 20:

[quote]
(..) promising proposals for a SCS (Single Channel Simulcast)
option are currently being evaluated (..)
Even if single channel simulcast may prove a difficult goal to
achieve (..)
[unquote]

DRM is not IBOC,
correct me if I'm wrong.

gr, Hein