I read the proposed rule making and did not find any reference to frequency/band. So, where is it saying SS is allow but only on 220Mhz and above ?
On Thu, Mar 18, 2010 at 6:11 PM, KH6TY <kh...@comcast.net> wrote: > > > Extensive tests on 70cm using ROS 16 baud spread spectrum have been > disappointing. ROS appears to be unable to survive the Doppler shift and > Doppler induced "flutter" so prevalent on that band. The hope was that ROS > 16 baud would make traditional communications possible that were difficult > on SSB phone because of the Doppler shift and "flutter". However, the tests > show that Olivia 32-1000, in half the bandwidth, and Olivia 16-500, produce > print when ROS only prints garbage. This, together with the fact that both > stations must be within 400 Hz of each other before even trying to > communicate, instead of being able to tune with the mouse as is possible > with Olivia, makes it very difficult to achieve a QSO on 70cm using ROS. > Olivia has therefore proven to be much more successful than ROS on UHF. > > Tests using the ROS 1 baud variation will be made next, but the slow speed > of that mode is more suited to EME communications than normal QSO's. > > In two weeks of monitoring ROS 16 baud on 20m, there has been only one > observed case where the S/N was under where Olivia 32-1000 can decode, so > even on HF, there does not appear to be any justification for using such a > wide mode, even if spread spectrum were permitted on HF in the US. Just use > Olivia or MFSK16 instead when band conditions are poor. The new narrow band > ROS modes were not tested, since a mode to do better than Olivia is what is > needed, and the spread spectrum mode of ROS held the best hope. As it > stands, only CW is better than Olivia under the worst conditions, and only > when copying by ear, but CW is only a little better than Olivia 16-500. We > have also found that the more narrow Olivia modes (i.e. < 500 Hz wide) are > also too greatly disturbed by Doppler to be useful either. > > If anyone is within 200 miles of FM02, has 100 watts and an antenna gain of > 17 dBi or greater, and would like to try ROS 16 baud on UHF, I am available > to do that. > > I promised to post the results of our attempts to use ROS on UHF on this > reflector, and this is what we have found. So, it looks like Olivia is > currently still the best digital mode to use on UHF, VHF, or HF for normal > (not EME) digital QSO's. > > 73 - Skip KH6TY > > > > > Trevor . wrote: > > > > Regarding Spread Spectrum Notice of Proposed Rule Making (NPRM) > http://www.arrl.org/news/stories/2010/03/18/11396/?nc=1 > > It proposes to reduce some of the restrictions on Spread Spectrum but > unfortunately does nothing about permitting the use at HF and VHF of SS > modes that completely fit within the bandwidth of a phone signal (say 3 kHz > on HF and 15 kHz on VHF). > > It says comments can be filed on or before 30 days after date of > publication in the Federal Register. Instructions on how to file comments on > the NPRM only are listed on pages 6-7 in the NPRM. > > http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-10-38A1.pdf > > Electronic Comment Filing System > http://www.fcc.gov/cgb/ecfs/ > > 73 Trevor M5AKA > > >
