> John K8OCL wrote: > The ARRL HSMM Working Group recommended at least the same > bandwidth for HF digital research and advancement as the > current ARRL bandplan recommended for a old legacy mode > such as AM.
Hi John, There is really no sensible reason that AM should get special treatment in a bandwidth-based spectrum management plan. Especially, when bandwidth-based definitions may be used to allow AM on par with other emission types. In 2005, I suggested the use of a power/bandwidth mask that would accomodate AM, as well as provide for other emissions at wider bandwidth, but with similar spectrum use impact as AM... See this image: http://www.hflink.com/bandplans/spectrum_mask.jpg Basically, the power mask definition principle is simple... If transmitter necessary bandwidth exceeds 3kHz, then: Power must not exceed 1500W PEP in 3.5kHz occupied bandwidth, and power must not exceed 200W PEP in 10kHz occupied bandwidth. So, when necessary bandwidth doesn't exceed 3kHz, there is no need for the operator to measure or calculate bandwidth. It is only when wider bandwidth is used, that it puts the responsibility upon the operator to control power vs bandwidth according to the stepped power mask. Just think about the kB/s throughput you could deliver with a stepped power 200W/1.5kW OFDM signal within this mask! Or, alternatively, a flat response signal with 10kHz bandwidth at 200W. Using time-share techniques, there are a lot of interesting new things that could be done. Certainly, there is enough spectrum space to carve out 50kHz of spectrum for this in the 80m, 15m, and 10m bands for this. On the 20m and 40m bands, with a small chunk, maybe 20kHz of spectrum could be used, and a slightly lower-powered mask could be defined: 100W @ 3.5kHz Occupied Bandwidth 20W @ 10kHz Occupied Bandwidth Certainly, this would have less spectrum impact than the kilowatt AM phone signal that everyone knows and loves so much. Bonnie Crystal KQ6XA Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
