> In this case that would be wrong. The headphone manufacturers > complained that good foam costs too much and were allowed > to get away with tissue paper and now everyone pays for > allowing lobbyists and lawyers run the FCC and ignore good > design principles
No, its not just "good foam" that is required, it is surrounding each Headphone and each Human wearing them with an 80 dB Accoustic chamber to solve the problem of the LightSquared Rock band in the room! There are TWELVE or more orders of magnitude (120 dB) between a nearby transmitter and a nearby GPS receiver. That is, the transmitter is 1,000,000,000,000 times stronger than the sensitivity of the nearby GPS receiver. It is absurd to expect every $20 GPS to have 120 dB filters. Ham radio only needs 40 dB out of band rejection to be within FCC specs. NASA demands 80 dB out of band rejection. LightSquared wanted every $20 GPS MFR to install 10,000 times more filters than even NASA! No, the analogy is correct. That is why the FCC has always (when they had real engineers anyway) had band plans that SEPARATE Transmit bands from weak-signal satellite receive bands. It is ludicrous to allow a bunch of clueless lawyers try to buy their way into putting Transmitters in the the RECEIVE ONLY satellite bands. Bob, WB4APR From: Robert McGwier [mailto:rwmcgw...@gmail.com] Sent: Wednesday, February 29, 2012 7:30 PM To: Bob Bruninga Cc: amsat-bb@amsat.org Subject: Re: [amsat-bb] Lightsquared Analogy On Feb 29, 2012 3:01 PM, "Bob Bruninga" <bruni...@usna.edu> wrote: I finally figured out a good analogy about the LightSquared and GPS fiasco. --------------- There is a "music room" where people can go and, with headphones, listen to their own music. No one disturbs anyone else. Everyone is happy. A LightSquared rock band comes into the room and begins to play at max volume, and then insists there should be no problem because the headphones work just fine in providing the isolation between what each person is listening to. Therefore the interference to everyone in the room is not their fault, but the fault of the Headphone Manufacturers! Bob, WB4APR _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
