FCC Releases "symbol rate" NPRM

Discussion in 'Amplitude Modulation' started by K5UJ, Jul 29, 2016.

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  1. AG6QR

    AG6QR Premium Subscriber QRZ Page

    Yes, they seem to be explicitly rejecting the ARRL's request for a 2.8 kHz bandwidth limit, allowing a single transmission to be as wide as desired. In theory, one could fill the entire CW/data portion of a band with a single transmission. Sure, one could easily argue that that's not "good amateur practice", but where is the limit? If the FCC says that 2.8 kHz is too narrow to set the limit, then is 10 kHz OK? How about 25 kHz? That would be half of the 30m band, or a huge fraction of the data portion of the 17m band.

    It's hard for us to listen and avoid interference if we have widely varying bandwidths. I really think 3 kHz is wide enough, but if it isn't, at least let the rules keep the wider transmissions separated from the CW portions of the bands.
  2. K5UJ

    K5UJ Ham Member QRZ Page

    Having these numerical hard bandwidth limits seems like a solution in search of a problem. I don't recall a super wide emission ever bothering a narrow mode. 98 or 99% of the time, hams are pretty good about not running a mode of transmission that is out of place, like slopbucket down at the low end of 160. Yes, there are a few lids but should there be a rule for everyone just because a handful of hams are jackasses.

    Actually CW seems to be the most bulletproof mode when it comes to wideband QRM because the receiving station can narrow the passband of his receiver down to a few hundred cycles and deal with it, assuming the transmitting station isn't sadistically running QRPeee.

    From my experience most of the problems have to do with digital vs. analog phone, namely digital slopbucket lids causing QRM to analog phone. I am unable to understand why these "image" transmissions are not confined to a data subband. One rule that would help keep the noise operators on the straight and narrow would be a CW ID requirement on all non-analog modes. Simply program in a CW ID at 30 wpm at the end of a digital transmission so the rest of us can know who the scofflaws are. This would be completely unobtrusive and easy with software.
  3. W2VW

    W2VW XML Subscriber QRZ Page

    This is amateur radio.

    Enforcing numerical bandwidth limits would take enormous manpower.

    From what I see on online amateur sites many hams have the idea bandwidth is like counting apples. If you have one, two apples there's no doubt. Anyone can measure two apples.

    2KHZ bandwidth is another matter entirely.

    If people are that interested on bandwidth regulations they should publicize measurement techniques.

    Otherwise hams would need a certification sticker on the side of their rigs to show someone with knowledge and responsibility has set it. The mic gain knob would need to be sealed like an electric service meter. Does this remind anyone of another radio service? It should.

    Even with all that in place there would be a percentage of emotionally arrested amateurs who would file numerous complaints with FCC to get even with those who have crossed their path.

    The AM community in the Northeast had one such individual a few years back who caused a whole lot of problems. Fortunately he can only be found on the higher bands these days.
  4. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    One alternative I have thought of would be to open all the HF bands to any mode, any frequency, without sub-bands, as 160m is now. One problem with that would be during phone QuaRMtests and DX pile-ups, SSB signals would extend all the way down to the bottom end and completely wipe out CW, just as they now do all the way down to 1800. A way to avoid that would be to assign a narrow segment at the bottom of each band, perhaps re-purposing the present extra class CW segments, to CW-only or modes of comparable bandwidth, similar to the weak-signal CW segments at the bottom ends of 6m and 2m.

    Another approach might be to expand to three distinct sub-bands, one for narrow-band modes like CW, narrow-shift Baudot, PSK, etc., one for wider-band "Digital" including digital data, voice, image, SSTV or anything else 'digital', and thirdly, the present analogue phone/image segments. I would even give up that 3600-3650 segment of the 75m phone band that ARRL wants to give to automatically-controlled digital, if they made that into a digital sub-band to which digital modes would be limited to operate. But I doubt very much that the FCC would go along with the additional administrative and enforcement duties required to further micromanage amateur radio. Maybe the rejection of the 2.8 kHz bandwidth limit is a sign that the FCC is more willing to let hams hash out frequency usage amongst ourselves as long as we stay inside the boundaries of our playground.
  5. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    For sure on all the above.

    I have decided to send a hardcopy to the FCC since the pdf or docx file won't upload.

    Here is an excerpt of two paragraphs included in my response:

    AC0OB - A Place where Thermionic Emitters Rule!
    Besides, when you're a Ham, you experiment with and improve boat anchors - that's what you do!. [​IMG]
    Last edited: Aug 13, 2016
  6. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Here is a set of interesting comments from an operator who has criticisms, especially regarding the timing of the original ARRL RM:

    "...For the record, the FCC must note that in its 16 page filing of RM 11708, the ARRL never once mentioned the word ‘interference’, and never once inferred or implicitly acknowledged that interference could be a problem for US or global amateur narrowband operators. RM-11708 cobbled together an “apples to oranges” argument as it advocated for 2.8 kHz wide channels, based on the rarely used, low power 5 MHz SSB channels that are only used in a few countries, while completely ignoring the fact that the Commission has never allowed single sideband signals in the lower portion (data sub band) of the HF amateur bands...."


    AC0OB - A Place where Thermionic Emitters Rule!
    Besides, when you're a Ham, you experiment with and improve boat anchors - that's what you do!. [​IMG]
  7. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    Don't let the deadline slip up for filing comments to the FCC regarding the Baud Rate NPRM, WT Docket 16-239 (formerly RM-11708). Comments are due 11 October 2016 and reply comments 10 November. Now is the time to be composing and formulating whatever you plan to submit. We have been sidetracked with other issues recently, the tower marking bill for example, and it would be too easy to let this slide and the deadline to creep up or even slip by before we know it.

    From what I have heard recently, the FCC does indeed pay attention to comment deadlines, even though late filings are still posted on the ECFS site. Several late filers on recent petitions have complained that the FCC ignored their submissions.

    Docket 16-239 can be viewed here:

    Filed comments can be viewed here:

    So far, only 41 comments have shown up on the FCC site.

    Several issues have been brought up that could affect AM privileges. First and foremost, is the issue of specific bandwidth limits. In its petition, ARRL proposed a bandwidth limit of 2.8 kHz for RTTY/Data modes, while removing the 300 baud cap on digital modes. In its Notice of Proposed Rulemaking, the FCC proposes to go along with removing the cap on baud rate, but without imposing the bandwidth limit.

    Understandably, many CW operators feel threatened by a proposal to allow unlimited bandwidth digital signals in the traditional CW bands, and at least one of the submitted comments asks the FCC to impose specific bandwidth limit on all modes, including a 6 kHz limit on AM phone, essentially a redux of the ARRL's defunct Regulation-by-Bandwidth petition. While unlimited bandwidth digital signals may be problematic, we must let the FCC hear loud and clear that not everyone is in favor of imposing specific enumerated bandwidth limits. The main argument against specific bandwidth limits is that the current system of a vaguely worded limit of "good engineering and amateur practice" allows amateurs the maximum flexibility for experimentation and self-instruction in the radio art, that specific bandwidth limits would impose a new burden of compliance on amateurs, and would impose a new burden of enforcement on FCC field personnel.

    Other commenters have proposed adding a third sub-band for digital transmission, restricting all forms of digital modes to that segment. But the question would be where to locate that segment. Many CW and RTTY operators want to take a large chunk of spectrum away from the phone bands, particularly on 75-80m, even though there is little evidence that the current CW segments are insufficient to accommodate the amount of CW activity currently heard on the bands. Again, some comments I have seen suggest a redux of the ARRL's petition RM-11759, which has proposed to move the boundary between CW/Data and Phone from the current 3600 kHz to 3650 kHz.

    I'm not sure the FCC would go along with any new sub-band segmentation that would require additional enforcement efforts on their part, but when these proposals come out, one never knows how they will end up. Sometimes the final rule is the diametric opposite to what was originally proposed in the initial petition or NPRM.

    An idea that has occurred to me would be to eliminate the 25 kHz Extra Class segment at the bottom end of each of the HF bands, and convert those segments to CW-only sub-bands, similar to the 100 kHz CW segments at the bottom end of 6m and 2m, allowing the digital stuff into the rest of the traditional CW/RTTY/data segments as the FCC now proposes. With the elimination of the Morse code test for all licence classes, the Extra class CW band no longer serves its former purpose as a narrow exclusive segment limited to what should be competent, experienced CW operators. Nevertheless, keeping digital and RTTY signals out of that portion would make it more attractive and useful for CW enthusiasts, regardless of their licence class and code speed.
    N6YW likes this.
  8. W6RZ

    W6RZ Premium Subscriber QRZ Page

  9. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    I'm not sure that's the proper avenue to file comments, even though RM-11708 is written in the heading of the Docket, beneath the NPRM number. This is now a rulemaking proposal issued by the FCC, no longer a petition. The comment deadline for the petition is long past. Those 300 commenters may have wasted their time.

  10. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    In my hardcopy to the FCC, asking for a rejection of the PRM, my header was as follows:

    so as to cover all bases.

    BTW, in the Upper Left corner of the ECFS website it says:

    Docket RM-11708 filings
    Opens a New Window.

    Amendment of Part 97 of the Commissions Amateur Radio Service Rules to Permit Greater Flexibility in Digital Data Communications
    Bureau Name
    Wireless Telecommunications Bureau
    Date Created
    Total Filings
    Filings in last 30 days

    In my paragraph A., I had some criticism of the ARRL as their ignorant statement really bugged me:

    A. Bit, Symbol, and Baud rates

    "The A.R.R.L. stated on Page 3 of RM-11708 that, 'Such an approach would also standardize the criterion used to determine the permissibility of data transmissions, and it would eliminate the confusion that often exists between symbol rate and baud rate.'

    A cursory search of articles will find, for example, an excellent article by Lou Frenzel (W5LEF, author and professor of electronics) in Electronic Design of April 27, 2012, which explains Bandwidth, Bit, Symbol, and Baud rates. Therefore, the only confusion on this subject seems to exist within the A.R.R.L. and not the general public."

    I still feel the major pushes of late have been from Pactor mode eqpt. manufacturers such as
    http://www.p4dragon.com/download/InstallationGuide_DR-7X00.pdf and their minions.

    There are more efficient data protocols with spectrum conserving bandwidths than Pactor 4, as mentioned in post #15.

    AC0OB - A Place where Thermionic Emitters Rule!
    Besides, when you're a Ham, you experiment with and improve boat anchors - that's what you do!. [​IMG]
    Last edited: Sep 1, 2016

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