Hi The FCC (like most US agencies) has a mission to promote as well as regulate. The promotion side is what drives them to allocate frequencies in a way that you can reasonably produce gear. They have always come back years later and tried to change things around. Every time, the same issues get hashed over. Sometimes a change actually gets made, sometimes not.
What's surprising with the GPS impact here is that the usual conversations are taking place a bit late in the process. The impact on legacy timing gear is one part of a much larger issue here. Hopefully it does not get lost in the back and forth. There's an enormous amount of gear out there that gets timing off of GPS. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of William H. Fite Sent: Friday, June 10, 2011 9:47 AM To: [email protected]; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS interference and history... You folks are all far more knowledgeable than I on these issues so I have a question: To what extent, from both an engineering perspective and from the standpoint of public policy, should it be the obligation of transmitter and receiver manufacturers to design and build devices with sufficient filtering, et alia, to avoid or at least vastly minimize problems such as those described below by Didier? I suppose from an engineering standpoint the issue is one of do-ability and from the public policy perspective, how much it is reasonable to expect both those who transmit and those who receive to pay for equipment that will minimize interference problems, given that we are running out of spectrum and demands for chunks of it will continue to pour in. Both technical information and philosophical ramblings will be appreciated. Bill On Fri, Jun 10, 2011 at 9:16 AM, <[email protected]> wrote: > The problem is that many FM receivers leak LO signal, so if 2 receivers are > next to each others and set 10.7 MHz apart, one will be receiving the LO of > the oter. > > Didier KO4BB > > Sent from my BlackBerry Wireless thingy while I do other things... > > -----Original Message----- > From: Chuck Forsberg WA7KGX N2469R <[email protected]> > Sender: [email protected] > Date: Thu, 09 Jun 2011 12:16:48 > To: <[email protected]>; Discussion of precise time and frequency > measurement<[email protected]> > Reply-To: Discussion of precise time and frequency measurement > <[email protected]> > Subject: Re: [time-nuts] GPS interference and history... > > The image frequency for an FM receiver with a 10.7 mHz IF > is 21.4 mHz above or below. Perhaps they were worried about > receivers with IFs in the 5 mHz range? > > -- > Chuck Forsberg WA7KGX N2469R [email protected] www.omen.com > Developer of Industrial ZMODEM(Tm) for Embedded Applications > Omen Technology Inc "The High Reliability Software" > 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
