[CQ-Contest] RM11708 and the Future
Charles Harpole
hs0zcw at gmail.com
Tue Aug 23 19:00:29 EDT 2016
Ward, I would like to have a Model T, not because it is "up to date" but
because IT IS FUN.
Lots of hams are old; old is fun, too.
73, Charly
On Wed, Aug 24, 2016 at 3:43 AM, Ward Silver <hwardsil at gmail.com> wrote:
> First, I do agree with N9NB that there needs to be a bandwidth limit in
> the amateur bands - this has been confirmed by the FCC in numerous
> communications and opinions about overly-wide phone signals and also by
> 97.307(f)(1) which limits the modulation index of angle-modulated phone
> emissions to less than 1 at the highest modulating frequency. Clearly, the
> idea of a maximum bandwidth is considered good practice in the phone
> sub-bands and a similar limit in the RTTY/data sub-bands does not need to
> strangle technical innovation. Nevertheless, it is not sufficient to rely
> on the "necessary" and "good practice" wording in 97.303(1) because neither
> is strong enough to be meaningful without creating endless arguments and
> perceived loopholes. So just place a reasonable "roofing bandwidth" on
> amateur radio emissions below 30 MHz - 3 kHz? 6 kHz? 10 kHz? - and let us
> sort it out as we do every day!
>
> [If the maximum bandwidths of phone and data signals are to be linked in
> one rule, a simple administrative fix could be made by the very simple
> change of applying 97.307(f)(2) to all of the HF bands - renumber it from
> 97.307(f)(2) to 97.307(g) or add (2) to all of the HF bands in 97.305.
> Digital voice would remain confined to the phone bands because even though
> it is transmitted as bits, the overall package is still classified as a
> phone emission, just as digitized images are still considered image
> emissions (facsimile). (See 97.3(c) and 2.201)]
>
> Let's get a grip, though...in my opinion:
>
> PACTOR 4 is already permitted everywhere else in the world and has not
> ruined ham radio yet. PACTOR 3 and PACTOR 4 modems are expensive - the
> rush to use >$1000 modems to exchange non-commercial traffic at <10 kbps
> (at best less than 1/5th of dial-up rates) over HF is not a very strong
> business case. While it is popular to gnash our collective teeth about
> those impure "boaters," (Oh, the fiends, checking their stocks via amateur
> radio!) the primary use of the Winlink system is rapidly shifting toward
> emcomm/public service, which is prominent in our Basis and Purpose of
> 97.1(a). Using faster modems actually reduces band occupancy in terms of
> Hz-sec for any particular message - although better performance *might*
> increase the number of messages. But at <10 kbps and with the horrible
> things that HF does to a channel...I just don't see a stampede
> materializing.
>
> More importantly, ham radio needs to get with the program - our
> over-reliance on decades-old analog modes is laughable. You want new
> technical blood to fulfill 97.1(d)? Try explaining to anyone under 40 that
> our primary HF digital modes run at 31 baud or use the 80-year-old 5-bit
> Baudot code developed for electromechanical printers and which can't even
> handle the full alphanumeric character set. Inform them of our 300-baud
> symbol rate limit below 30 MHz and, after their initial disbelief, you will
> get a look of pity followed by complete disinterest. In most student
> papers at engineering conferences everything under 1 GHz is considered
> BASEBAND AUDIO!
>
> Nor is it a good idea to further splinter the ham bands - it just creates
> unreasonable expectations of ownership or occupation. Many operators
> discovered during the W1AW/portable year how channelized 40/75 meters had
> effectively become, simply due to squatter's rights. We are always
> pooh-poohing band plans during contest weekends - rightfully - and any kind
> of reserved-for-narrowband allocation will simultaneously create the
> expectation that narrowband signals stay within it. There is lots of room
> on the bands for all kinds of signals if we could only get over the notion
> of reserved sub-bands, calling frequencies, net lists, and
> been-here-for-years. We have these Big Knob thingies we can use. We're not
> rockbound any more. Frankly, I think the whole notion of band plans needs
> to be greatly de-emphasized. We are the most flexible telecommunication
> service of all - why are we so intent on throwing that away?
>
> Consider the use of "smart spectrum" SDR-based displays showing where all
> the signals of various types are and aren't. (The RBN almost does that
> now...) With so many different modes and more on the way, it seems to me
> that approach is a better way of going forward in line with the "cognitive
> radio" approach to spectrum management and our mandate in 97.1(b) and (c).
> Alternatively, if the bands are going to be segregated, then do it
> according to behavior (see my Contest Update editorials of Sep/Oct 2005)
> which is the root cause of most inter-mode conflicts, anyway.
>
> A real problem that has been identified by many, and which is something we
> really *do* need to address for *all* modes, is transmitter linearity and
> noise. We have fantastic receivers that can hear a skeeter fart but the
> bands are full of our own trash from non-linear and noisy transmitters -
> even the expensive ones. (That we are still dealing with key clicks in the
> year 2016 is ridiculous.) There are plenty of techniques that we could
> adapt from the wireless data industry, such as pre-distortion and
> higher-voltage final transistors, all well-characterized mature
> technologies. The linearity issues with complex I/Q data signals are the
> same as for speech modulation. Let us solve noise and transmitter IMD and
> it will be a lot easier for everybody to get along. Digital modes can be a
> lot more noise-tolerant, too, and that might help a lot with the new
> reality of all spectrum, just as FM was invented by Armstrong in response
> to AM static.
>
> Also...this CW...I turn on my radio most weekdays and wonder where is this
> precious commodity we are trying to preserve? Sure - contest weekends sure
> load up the bands - but the other 90%+ of the time the CW areas are pretty
> empty. I love CW but I am not of the opinion that we have to hobble the
> service and keep it increasingly technically irrelevant in order to
> preserve a century-old mode that isn't the backbone of the service it once
> was.
>
> The sky is not going to fall. Yes, I will swear like a sailor when a data
> signal wipes out my CW run frequency, but then I'll use my Big Knob and
> start again somewhere else. (Or just stay there and duke it out.) Ham radio
> needs to accommodate useful data modes if it is going to survive to
> celebrate its second century.
>
> 73, Ward N0AX
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--
Charly, HS0ZCW
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