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[hfsig] Re: [Flexradio] The final nail in the coffin of Morse ?

Robert McGwier rwmcgwier at comcast.net
Sat Jul 23 07:03:22 UTC 2005


Right.  I believe you.  I am indeed hoping for a lot more than we can do 
now "officially"

Bob
N4HY




Walt DuBose wrote:

> Bob,
>
> 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 
> meeting
>     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 
> double-sideband
>     AM with bandwidth of up to 9 kHz was retained."
>
>     "Significantly, the Board also agreed that maximum permitted 
> bandwidth
>     should be defined in terms of necessary rather than occupied 
> bandwidth.
>     In addition, the modified proposal removes the exception for 
> independent
>     sideband (ISB) emissions--apparently not used in the Amateur 
> Service--
>     and drops certain mode restrictions on Novice and Technician class
>     operators."
>
>     "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." 
> §97.101(a)   
>     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.
>
> 73,
>
> Walt/K5YFW
>
>
> 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!
>>>
>>>
>>> Bob
>>>
>>>
>>>
>>> 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?
>>>>
>>>> Walt/K5YFW
>>>>
>>>
>>>
>>>
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