Topband: ARRL Bandwidth petition

[Jim Monahan]

  "K4KYV wrote:
  I can see the rationale of reserving some space for narrow-band modes like 
  CW and PSK-31, to protect against interference from wideband sources such as 
  analog voice.  But if there is to be a segment defined at 3 kHz, what is the 
  point of creating two segments, one to exclude voice and another to exclude 
  RTTY-like digital modes?  Interference-wise isn't a 3-khz wide signal a 
  3-khz wide signal regardless?  Would digital radiotelephony be considered 
  voice or non-voice? Isn't this adding unnecessary complication to a subband 
  structure that is already more complex than what exists anywhere else in the 
  world, especially after licence class segmentation is factored in?"

  The consideration is to remember that the proposed subbands are to include
  digital modes UP TO 3 KHz. These subbands would include modes that typically use
  500 Hz and 2.7KHz. The 200 Hz limit would be reserved for the CW mode and some
  data modes like PSK31.

  Separation of digital from traditional analog modes as the separation from narrow/wide
  band modes, which has been in place for decades, is its own example and precedent.

  As described, in part, from the petition:

  ARRL was guided by advice from an Ad Hoc Digital Committee formed to advise on issues that arise from the development of new high-frequency digital data modes of operation. In summary, the recommendations of that Committee were to delete the symbol rate limitations in Sections 97.307(f)(3) and (4); to segment the bands below 28.0 MHz by nominal bandwidths of 200, 500 and 2700 Hz as upper limits; and to require that digital data protocols be published, to facilitate monitoring. The Committee was aware of the bandwidths and frequency segments under consideration by Region 1 of the International Amateur Radio Union. The bandwidth of 200 Hz was chosen to accommodate Morse telegraphy and the narrowest RTTY/data emissions. A bandwidth of 500 Hz would permit the foregoing modes and a wide range of RTTY/data modes and some image modes yet to be designed. IARU Region 1 studies chose a bandwidth of 2700 Hz for SSB telephony and to accommodate digital voice and higher speed data. The Rules already specify a bandwidth of 2800 Hz for SSB voice in the 60-meter band. As the issue is a maximum regulatory bandwidth, not practice, which varies from (say) 2400 to 2800 Hz, a bandwidth of 3000 Hz is recommended. 

  "K4KYV wrote:

  I am concerned about possible unintended consequences of this proposal.  For 
  example, the status of AM phone is supposed to be specifically protected, 
  but if the League proposal is adopted, instead of being expressly permitted 
  by language embedded in the rules, AM would be protected by nothing more 
  than a footnote."

  I am also concerned about the unintended consequences, Don. Yes, issues like license class
  segmentation and the AM mode all need to be part of the consideration. The point is that this
  needs to be discussed and commented on by the community so that the ARRL has the most
  intelligent and informed input possible. How they may use that input may be another matter!

  "K4KYV wrote:

  I suggest that everyone interested in the future of amateur radio read the 
  text of the proposal carefully, and try to come up with an informed opinion 
  and transmit it to the website as requested."

  Absolutely!

  The idea here is to commence discussion, generate comments and follow the path of
  this petition through the FCC process. It is in everyone's best interest to participate whether
  they support this idea in whole, part or not at all.

  But, doing NOTHING is the wrong way to go and I don't think you are suggesting that. Digital
  modes are the future of communications and ham radio. Change is certainly difficult.

  And, I remember back in the late 1950's when SSB started to appear in the AM bands
  and the wars that resulted from that.

  73, Jim, K1PX

  K1PX at msn.com<mailto:K1PX at msn.com>



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