So 10 times is not a property of SS. Yes 73 Rein W6SZ
-----Original Message----- >From: W2XJ <w...@w2xj.net> >Sent: Jul 13, 2010 8:46 PM >To: digitalradio@yahoogroups.com >Subject: Re: [digitalradio] Re: Random data vs Spread Spectrum > >It is generally accepted that 10 times bandwidth is the minimum necessary to >achieve enough processing gain to make the use of SS worthwhile. > > >On 7/13/10 3:55 PM, "J. Moen" <j...@jwmoen.com> wrote: > >> >> >> >> >> >> >> There's the generally accepted definition of SS, quoted below and referring >> to >> bandwidths greatly exceeding what's necessary, and then there's the way the >> FCC regs are written, which do not refer to that definition. >> >> I think just about everyone, or maybe absolutely everyone who cares about the >> FCC regs, thinks in this case they are inappropriate, but the fact is, they >> do >> not allow for narrow-band SS, even though it would cause no real harm. >> >> The regs should be changed, but until they are, we in the US can not use SS >> below 220, or we can move to another country, or we can violate the regs, >> and/or we can campaign to change them. But saying you don't agree with a law >> so you don't have to follow it is not the right way. >> >> Jim - K6JM >> >>> >>> ----- Original Message ----- >>> >>> From: rein...@ix.netcom.com >>> >>> To: digitalradio@yahoogroups.com >>> >>> Sent: Tuesday, July 13, 2010 11:23 AM >>> >>> Subject: Re: [digitalradio] Re: Random data vs Spread Spectrum >>> >>> >>> Hi Alan, >>> >>> Why did you wait so long with contributing here? >>> Please explain. >>> >>> ++ In Feb of this year I quoted from the ARRL's Spread Spectrum Source book >>> page 5-2 ++ >>> >>> " Spread Spectrum Fundamentals " >>> >>> SS systems employ radio frequency bandwidths that greatly exceed the >>> bandwidth necessary >>> to convey the intelligence. >>> >>> Bandwidths for SS systems generally run from 10 to 100 times the >>> information >>> rate. >>> >>> etc etc. >>> >>> I got shouted out of the Group by addressing the use of ROS in the US by >>> the >>> experts on >>> SS. >>> >>> 73 Rein W6SZ >> >> >> >> >
