[600MRG] Removing symbol rate restrictions on 630m/2200m

[Brian Justin, WA1ZMS]

Scott-

At the risk of saying too much in an open forum, I will say that I was asked by the League for my personal technical inputs to help guide a formal reply to the FCC’s NPRM.  It was humbling to be “invited”.

As for 2200m…..my personal opinion is:
We need to be very forward thinking as another similar NPRM is unlikely for decades.  While 99.9% of today’s emissions are “ultra narrowband” vs ACSSB or something else such as 4-level QAM, etc… the actual likelihood of someone being able to fill the entire band with enough power spectral density given the EIRP limits and the extreme Q of electrically small antennas should pose no tenable risk to WSJT-like emissions.   That said, when the band first became available in Germany, two hams did have a very one-time very narrow BW SSB QSO just to say “we did it!”.  Antenna matching I’m certain was a challenge. (I have had SSB QSOs on 630m with NO3M, but not on 2200m.) Honestly, I like to try just once.  But what I “want” does not an effective NPRM reply make.

So a half-way point to look at it might be a frequency hopped direct sequence spread spectrum emission covering only 750Hz of BW. Publish that each sequence will start with a synch or dotting pattern at say 100mS after each GPS second.

Perhaps someone will write the “anti-WSJT“ where 1kHz of BW or more is used. Who knows what the future may hold.  Notwithstanding, the real way to protect incumbent users is via the traditional gentleman’s agreement of which mode operates where on a band.  

Some may not agree with the strategy, or it sounds weak in theory. 

I’ve probably said too much already, and my intent is not to start a debate or argument, pro or con any emission mode.  I hope it just sets the stage for something “new” in the future. That’s all. My 2 cents.

73,
-Brian, WA1ZMS


> On Jan 11, 2024, at 18:39, Scott Armstrong <aa5am.scott at gmail.com> wrote:
> 
> 
> Hi all,
> 
> What are the group's thoughts on the proposal to allow 2.8kHz BW digi signals on the 630m and 2200m bands?  ARRL is supporting the removal of the restrictions.
> 
> http://arrl.org/news/arrl-responds-to-fcc-proposals
> 
> Seems to be a bit of a conflict on 2200m considering the band is only 2.1 kHz wide. I realize the difficulties of building antennas and radiating any sort of power on the bands plus the low activity. However, any broadband signal on 2200m could potentially monopolize the entire  band.
> 
> 630m has a little more wiggle room but not much.
> 
> Any thoughts?
> 
> Scott AA5AM
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