> Dave AA6YQ wrote: > There is unquestionably a bandwidth restriction > on HF for frequency-shift keying, ....
Hi Dave, Sorry, old friend, but you are incorrect. In the USA data/RTTY bands 160meters-10meters, the FSK rule is a "shift restriction". It is not a "bandwidth restriction". The attempt to equate or change the "shift restriction" into a "bandwidth restriction" was denied one year ago by FCC (May 2008). In the "Digital Stone Age Petition" denial FCC Order [paragraph 10] FCC said: "Our rules do not specifically limit the permissible bandwidth for RTTY and data emissions in the amateur HF bands." Plain and simple: FCC has conscientiously chosen to set no specific bandwidth limit for RTTY/data or phone emissions on HF/MF bands. For those who want bandwidth limits, perhaps it is time to reconsider a new bandwidth-based spectrum managagement petition to FCC? I have been a proponent of bandwidth-based spectrum management for ham radio. I don't believe that content-based spectrum management is conducive to advancement of RF digital technology, and I don't believe it is advantageous for hams. However, "The Law of Unintended Consequences" often applies to FCC rulings... and the petitioner may be severely disappointed by the outcome. A good example of unintended petition results was the one that reduced our freedom by making the 40 and 80 meter RTTY/data sub-bands get smaller! 73 Bonnie KQ6XA > Under the present "content-based" rules for > hams in USA, FCC has confirmed that there isn't > really a specific bandwidth limit for most types > of modern digital data signals on HF... other than the > maximum limit of the "RTTY/data subband" segment... > for example, on 20 meters, hams in USA can > legally transmit a 150kHz bandwidth data signal > (14000kHz to 14150kHz). > > See the FCC order May 7, 2008 denying the > "Digital Stone Age" petition: > http://www.hflink.com/fcc/digitalstoneage/FCC_denies_digital_stone_age_petition.PDF > > FCC explained further [in paragraph 11 of the order] : > "We believe that these rules provide amateur > service licensees the flexibility to develop new > technologies within the spectrum authorized for > the various classes of licensees, while protecting > other users of the spectrum from harmful interference. > We also believe that imposing a maximum bandwidth > limitation on data emissions would result in a loss > of flexibility to develop and improve technologies > as licensees' operating interests change, new > technologies are incorporated, and frequency bands > are reallocated." > > DATA SIGNAL BANDWIDTH LIMIT CHART HF/VHF/MF > ======================================== > Band========Data Signal Bandwidth Limit > 160 meters = 200 kHz > 80 meters = 100 kHz > 60 meters = 0 kHz (Data Not Authorized) > 40 meters = 125 kHz > 30 meters = 50 kHz > 20 meters = 150 kHz > 17 meters = 42 kHz > 15 meters = 200 kHz > 12 meters = 40 kHz > 10 meters = 300 kHz > 6 meters = 20 kHz > 2 meters = 20 kHz > 1.25 meters = 100 kHz > > Note1: Amateur Extra License, USA Amateur Radio Service > Note2: current as of 03-2009 > > More information and sources: > http://hflink.com/bandplans/USA_BANDCHART.jpg > > FCC, Subpart D--Technical Standards > §97.301 Authorized frequency bands. > §97.307 Emission standards. > > 73 Bonnie KQ6XA
