[hfsig] Re: [Flexradio] The final nail in the coffin of Morse ?
rwmcgwier at comcast.net
Sat Jul 23 02:03:22 CDT 2005
Right. I believe you. I am indeed hoping for a lot more than we can do
Walt DuBose wrote:
> I have to agree with Jeff. I don't think the Board's intent was for
> anything but legacy AM voice having 9 KHz bandwidth...certainly not
> data...especially not data.
> I believe that when the actual proposal is published, it will
> specifically allow only legacy AM voice to have 9 KHz bandwidth and
> all other modes must be not more than 3.5 KHz wide.
> The problem is "...Since OFDM - fade designed trellis QAM seems like
> AM to me anyway." If the Board doesn't see it that way and sees that
> 9 KHz bandwidth only applies to a legacy AM voice transmission, then
> you are stuck with 3.5 KHz bandwidth.
> I hate like heck to throw cold water on you notion; but, I'm afraid
> that the Board didn't intend for the a 9 KHz bandwidth signal to be
> anything but legacy AM voice and their proposal will have the
> exemption specifically for legacy AM voice and thus all other modes
> are stuck to 3.5 KHz bandwidth.
> Specifically, the ARRL prosal will follow this thought process...
> "The regulation-by-bandwidth issue dominated the Board's second
> of the year in Windsor, Connecticut. After a great deal of give
> and take
> among its members, the Board ultimately okayed raising the maximum
> bandwidth the EC had proposed for frequencies below 29 MHz from
> 3.0 kHz
> to 3.5 kHz. A provision permitting the continued use of
> AM with bandwidth of up to 9 kHz was retained."
> "Significantly, the Board also agreed that maximum permitted
> should be defined in terms of necessary rather than occupied
> In addition, the modified proposal removes the exception for
> sideband (ISB) emissions--apparently not used in the Amateur
> and drops certain mode restrictions on Novice and Technician class
> "The ARRL proposal would leave two important FCC rules unchanged.
> §97.307(a) says: "No amateur station transmission shall occupy more
> bandwidth than necessary for the information rate and emission type
> being transmitted, in accordance with good amateur practice."
> reads: "In all respects not specifically covered by FCC Rules each
> amateur station must be operated in accordance with good
> engineering and
> good amateur practice."
> So what then? On the one hand the Board says the bandwidth will be no
> more than 3.5 KHz except AM which can be 9 KHz wide and then says that
> no transmission shall occupy mode bandwidth than necessary for the
> information rate and emmision type being transmitted.
> So is OFDM a transmission type? What does "No amateur station
> transmission shall occupy more bandwidth than necessary for the
> information rate and emission type being transmitted" really mean? Ok
> so perhaps this is the outlet.
> So if my OFDM data transmission required 15 KHz to transmit 50 Kbps,
> is that OK?
> IMHO the only thing to do is to start now and write our own proposal
> to the FCC in a technical yet easily to understand format. A real
> challange...technical yet easily to understand.
> We are going to have to "one up" the ARRL so than any proposal they
> present will seem like (because it will be) a proposal that doesn't
> advance technology and the state of the communications art, rather one
> (ours) that promotes experimentation in the advancement of the
> communications art.
> The case must be clearly made that in data communications that
> increased throughput and robustness will require bandwidth wider than
> 3.5 KHz and it will be necessary to define high-speed and robustness
> as well as show, through the use of live (on-the-air) demonstrations
> or computer modeling/channel simulation the superiouity of any new
> mode or types of modes.
> My greatest fear in all this is that it will NOT foster further
> development or the need for SDRs. If this is true (with the passage
> of this sort of restrictive bandwidth as the League is proposing),
> then we can show that the League's proposal is NOT advancing the state
> of the art, rather preventing experimentation and advancement of the
> state of the communications art.
> On 23 Jul 2005 at 12:46 AMBob wrote:
> >I don't think 9 Khz would be widely tolerated without a specific say
> so. I am >not talking about theoretical legal limits. I could put a
> 200 Khz wide signal >on 20 meters in a few seconds by reaching over
> and turning on my FSK >transmitter on my Gnu Radio USRP and it is
> likely no one would even know I was >there. I am talking about
> "officially sanctioned" or blessed operations of the >type (say) Walt
> could take and put into ARES, RACES, FEMA, etc. sites.
> And yes, the proposal needs to be a recognized mode that we can
> present to and to be used by ARES, Red Cross, FEMA, etc.
> I believe that this will take the concerted effort on many individuals
> part to > make a bandwidth proposal to the FCC.
> Jeff King wrote:
>> There is effectively no bandwidth limit for OFDM modulations on HF as
>> we speak,
> > other then they be documented so not clear to me how the ARRL
> proposal will
> > cause anyones dreams to come to fruition.
>> On Sat, 23 Jul 2005 02:28:49 +0000, Robert McGwier wrote:
>>> You know my feelings already. These suggestions will enable real HF
>>> modems for the first time. I would not have dreamed of building a
>>> reasonable HF modem until the League proposals were brought
>>> forward. It would have just been a waste of time. I would have
>>> been run out of amateur radio for even suggesting doing MS188-
>>> 110A,B, etc. on (say) 20 meters in the phone band. Now I can see
>>> doing some serious work and it actually could be interesting at
>>> last. We could have 19-50 Kbps NVIS modems kicking some real butt
>>> in 9 Khz bandwidth. Since OFDM - fSince OFDM - fade designed
>>> trellis QAM seems
>>> like AM to me anyway. ;-). ade designed trellis QAM seems
>>> like AM to me anyway. ;-). Imagine having really serious digital
>>> voice over NVIS channels with S9 signals on 40 meters and running 5
>>> watts. Bring it on!
>>> DuBose Walt Civ AETC CONS/LGCA wrote:
>>>> First, the NPRM was not strictly an ARRL proposal, in fact, it
>>>> didn't appear to me to be the major proposal or proposal that the
>>>> FCC used to draft the NPRM.
>>>> Ok Bob, we know your views on CW, which are similar to my feelings,
>>>> but what about the Board's decision to limit HF bandwidth to 3.5
>>>> KHz with a 9 KHz exemption for AM? Don't we need wider bandwidths
>>>> for high-speed, robust data modes? Isn't the bandwidth limitation
>>>> going to be a greater factor in hingering the growth of amateur
>>>> radio than the Morse Code issue?
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