[CQ-Contest] 40M expansion?
Mark Steven Williams
k9gx at n4gn.com
Wed Nov 16 21:32:29 EST 2005
Go back and actually take the time to read the DRM codec information.
Modes A and B are already in use on MEDIUM WAVE stations, 9 khz (EU) or 10
khz channel spacings (Region 2)
Modes C and D are used in SHORTWAVE transmission where selective fading is
Shortwave broadcasters are already allocated 10khz bandwidth channels.
What the site explains is how the AAC plus codec compresses the data rate to
APPROXIMATE 19 kHz bandwidth audio. I use AAC coding every day at work for
remote broadcasts over ISDN lines. I'm a broadcast engineer. Our company
shall remain nameless, but we probably own a radio or TV station in your
ITU is NOT going to reallocate broadcast band plans and channel allocations.
The concept of DRM is to provide a robust, quality encode/decode scheme for
short and medium wave broadcasters to improve intelligibilty and reduce
susceptiblity to interference within existing channel allocations.
You should only wish and pray that DRM would be established as the worldwide
standard broadcast codec. It's open architecture would allow you to design
your own software driven receiver. Instead, those of us here in the U.S. are
having to suffer with Ibiquity's AM IBOC. It leaves a lot to be desired.
Your time would be much better spent railing against the potential
interference of BPL.
Who actually wrote that article? Don't think they have their facts
straight...and, in case you hadn't noticed, our "expanded medium wave AM
broadcast band" here in states was extended to 1700 kHz years ago.
See you on the radio.
Mark S. Williams
k9gx at n4gn.com
----- Original Message -----
From: "Lawrence Stoskopf" <stoskopf at tri.net>
To: <cq-contest at contesting.com>
Sent: Wednesday, November 16, 2005 8:46 PM
Subject: Re: [CQ-Contest] 40M expansion?
> Going to double post this to the top band reflector also:
> From the British ShortWaveMagazine:
> In a short note on p. 12 of the Nov05 issue:
> "..... www.drmradio.co.uk ... This site .... highlights that in order for
> DRM to provide near f.m quality it will actually require 18 kHz bandwidth
> rather than the 9 kHz often quoted. This will inevitablyh lead to
> to increase the spectrum allocated to broadcast services.
> This could come about through an expansion of upper limit of the Medium
> Wave band from 1611 to 1790kHz and increases in the s.w. Broadcast Bands.
> Such developments will make it harder for Radio Amateurs to achieve a
> 7000-7300kHz world-wide allocation. If the Medium Wave band was extended
> 1790KHz it could impact on Amateur 1.8MHz away at 1810 (sic.)."
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