[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Good Morning, Howie; I don't believe there has been any limitation (in the US, anyway) on SS emission types on 70cm and above since at least the late 1990's. I was hoping someone else would chime in since surely someone in this group knows more about that than I, but I'm pretty sure you can use whatever DS technique you want provided that whatever other direction in part 97 is followed. It seems things are pretty liberal to my reading, but I haven't had occasion to play in that space. It's my understanding that RM-11708--the current petition you mentioned--deals only with HF and has nothing to do symbol rates or anything else that would affect 70cm. That said, I do think it has everything to do with Wouter's concern about openness. It makes little difference to my daughter and me if the transmissions in amateur bands--satellite or otherwise--are operating under part 97, part 5, or part 15 if they are by design unintelligible to all but a select few. But that is only my picture of things. An HF only petition may be relevant to this group in the sense that this group has in the past put quite a bit of thought into this particular subject. The satellite community may have interesting perspective on some of this from its own experiences. If this subject is important to you the ARRL is asking for your thoughts right now: http://www.arrl.org/news/arrl-board-requests-member-comments-about-digital-modes Enough of that digressionone other thing that *may* be an issue to the satellite community is that the current SS rules might have some limitations in regard to international communications, but that too may be history. How that fits in with the *amateur satellite service* is not something I can answer, but if it is an impediment to a worthy project it would certainly have my support to change of needed, for whatever that is worth. Andy K0SM/2 On Mar 10, 2014, at 12:51 PM, Howie DeFelice howied...@hotmail.com wrote: Hi Wouter, I personally agree with the ITU recommendations and think that CDMA/ spread spectrum techniques can be useful for amateur satellite communications. Unfortunately individual national regulatory entities (especially the U.S. FCC) can take a very long time to adopt ITU recommendations. Current FCC rules define three spreading sequences based on defined tapped linear sequence generators; one 7 bit, one 13 bit and one 19 bit. That makes it difficult to deploy an effective CDMA system. I am sure provisions could be made for a STA ( special temporary authority) but I would anticipate this to be an involved process. I believe the current efforts by the ARRL to give amateurs more flexibility by adopting maximum bandwidth restrictions vs maximum symbol rate restrictions is a move in the right direction. If the purpose of amateur radio is to advance the state of the art, the rules need to be flexible enough to accommodate innovation. Of course, these are just the opinions of one person. I am sure there are as many opinions as there are subscribers to this list :) And yes, politics can be a great attenuator to progress... Howie, AB2S Date: Sun, 9 Mar 2014 11:48:40 +0100 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: wouter...@gmail.com To: howied...@hotmail.com CC: damonwa4...@gmail.com; amsat-bb@amsat.org Howie, CDMA is actually actively promoted by the ITU. Indeed all the details have to be published before launch, so everyone can demodulate it. Citing from the ITU satellite-amateur handbook: Amateur and amateur-satellite systems should have technical characteristics that provide worldwide interoperability, and allow origination, relay and termination of communications independent of other radio services. Design emphasis should be placed on reliability, robustness and flexibility of reconfiguration for efficient emergency communications. Multiple access techniques (FDMA, TDMA and CDMA) should be selected for optimum spectrum efficiency and frequency reuse. The selection of modulation techniques should take into account resistance to interference and immunity to adverse propagation conditions. I have been researching this for the QB50 mission, but strong pressures (mainly from the US) within the project killed the idea early on. The US is now actively putting satellites in 70cm with experimental licenses, which unfortunately means they could use CDMA without providing the spreading codes. The (majority of the) rest of the world is still using the amateur satellite service. Using CDMA would be beneficial for sharing the spectrum, but required coordination as well. I was trying to standardize the parameters (for QB50), so the IARU could be handing out orthogonal codes to satellite teams, so avoid clashes. But welcome to politics. Wouter PA3WEG On Tue, Mar 4, 2014 at 10:16 PM, Howie DeFelice howied
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
It's my understanding that RM-11708--the current petition you mentioned--deals only with HF and has nothing to do symbol rates or anything else that would affect 70cm. Andrew, As I read it RM-11708 directly affects the amateur satellite service at 144 and 435 MHz. RM-11708 can be read at http://apps.fcc.gov/ecfs/comment/view?id=6017477458 It proposes to delete all references to symbol rate from Section 97.307(f) http://www.ecfr.gov/cgi-bin/retrieveECFR?gpn=47y5.0.1.1.6r=PART#47:5.0.1.1.6.4.159.4 That would also remove the 1200 Baud restriction on 144 and the 19600 Baud limit on 435 MHz. I noted a reference to SS in a previous email. Some people use SS as a convenient abbreviation for Spread Spectrum but the FCC uses it differently. The FCC define the two letters SS as a separate term not an abbreviation, see Definitions 97.3(c)(8) http://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol5/xml/CFR-2011-title47-vol5-sec97-3.xml On Tuesday, 11 March 2014, 12:35, Andrew Flowers aflow...@frontiernet.net wrote: Good Morning, Howie; I don't believe there has been any limitation (in the US, anyway) on SS emission types on 70cm and above since at least the late 1990's. I was hoping someone else would chime in since surely someone in this group knows more about that than I, but I'm pretty sure you can use whatever DS technique you want provided that whatever other direction in part 97 is followed. It seems things are pretty liberal to my reading, but I haven't had occasion to play in that space. It's my understanding that RM-11708--the current petition you mentioned--deals only with HF and has nothing to do symbol rates or anything else that would affect 70cm. That said, I do think it has everything to do with Wouter's concern about openness. It makes little difference to my daughter and me if the transmissions in amateur bands--satellite or otherwise--are operating under part 97, part 5, or part 15 if they are by design unintelligible to all but a select few. But that is only my picture of things. An HF only petition may be relevant to this group in the sense that this group has in the past put quite a bit of thought into this particular subject. The satellite community may have interesting perspective on some of this from its own experiences. If this subject is important to you the ARRL is asking for your thoughts right now: http://www.arrl.org/news/arrl-board-requests-member-comments-about-digital-modes Enough of that digressionone other thing that *may* be an issue to the satellite community is that the current SS rules might have some limitations in regard to international communications, but that too may be history. How that fits in with the *amateur satellite service* is not something I can answer, but if it is an impediment to a worthy project it would certainly have my support to change of needed, for whatever that is worth. Andy K0SM/2 On Mar 10, 2014, at 12:51 PM, Howie DeFelice howied...@hotmail.com wrote: Hi Wouter, I personally agree with the ITU recommendations and think that CDMA/ spread spectrum techniques can be useful for amateur satellite communications. Unfortunately individual national regulatory entities (especially the U.S. FCC) can take a very long time to adopt ITU recommendations. Current FCC rules define three spreading sequences based on defined tapped linear sequence generators; one 7 bit, one 13 bit and one 19 bit. That makes it difficult to deploy an effective CDMA system. I am sure provisions could be made for a STA ( special temporary authority) but I would anticipate this to be an involved process. I believe the current efforts by the ARRL to give amateurs more flexibility by adopting maximum bandwidth restrictions vs maximum symbol rate restrictions is a move in the right direction. If the purpose of amateur radio is to advance the state of the art, the rules need to be flexible enough to accommodate innovation. Of course, these are just the opinions of one person. I am sure there are as many opinions as there are subscribers to this list :) And yes, politics can be a great attenuator to progress... Howie, AB2S Date: Sun, 9 Mar 2014 11:48:40 +0100 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: wouter...@gmail.com To: howied...@hotmail.com CC: damonwa4...@gmail.com; amsat-bb@amsat.org Howie, CDMA is actually actively promoted by the ITU. Indeed all the details have to be published before launch, so everyone can demodulate it. Citing from the ITU satellite-amateur handbook: Amateur and amateur-satellite systems should have technical characteristics that provide worldwide interoperability, and allow origination, relay and termination of communications independent of other radio services. Design emphasis should be placed on reliability, robustness and flexibility of reconfiguration for efficient
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
op 11-03-14 14:34, M5AKA schreef: It's my understanding that RM-11708--the current petition you mentioned--deals only with HF and has nothing to do symbol rates or anything else that would affect 70cm. Andrew, As I read it RM-11708 directly affects the amateur satellite service at 144 and 435 MHz. RM-11708 can be read at http://apps.fcc.gov/ecfs/comment/view?id=6017477458 It proposes to delete all references to symbol rate from Section 97.307(f) http://www.ecfr.gov/cgi-bin/retrieveECFR?gpn=47y5.0.1.1.6r=PART#47:5.0.1.1.6.4.159.4 That would also remove the 1200 Baud restriction on 144 and the 19600 Baud limit on 435 MHz. I noted a reference to SS in a previous email. Some people use SS as a convenient abbreviation for Spread Spectrum but the FCC uses it differently. The FCC define the two letters SS as a separate term not an abbreviation, see Definitions 97.3(c)(8) http://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol5/xml/CFR-2011-title47-vol5-sec97-3.xml Keep in mind that the downlink is not effected by usa rules so nobody is stopping a sat from downlinking 1M2 or more on 2 meter, offcourse it does not fit in the sat subband but that is not of concern to the ITU. 73 Andre PE1RDW ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Keep in mind that the downlink is not effected by usa rules This may be true if the owner of the satellite is not licensed in the USA or it is operating on some service other than the Amateur Radio Service. ITU recommends policy, it doesn't make or enforce law as I understand it. Before this gets too much further into the weeds, the purpose of my original post was to bring awareness that satcom is regulated by cooperative national authorities and is not the wild west of radio spectrum. This is true whether it is an amateur of commercial satellite regardless of size. Just because you can build it and get it launched does not mean it is legal. We all have a responsibility to be vigilant. I don't think too many people would intentionally put up a satellite in violation of the rule of law, but it is a complex issue. It never hurts to ask a question. - Howie AB2S ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
This may be true if the owner of the satellite is not licensed in the USA or it is operating on some service other than the Amateur Radio Service. ITU recommends policy, it doesn't make or enforce law as I understand it. Judging from the number issued in recent years the FCC seem happy to issue experimental licenses for satellites in 144/435/2400 including the use of emission types that aren't covered by existing FCC amateur radio regulations. AggieSat4's 153.6 kbps 4 watt 436 MHz downlink using ITU Emission Designation 406KF7DBN might breach the bandwidth limits of an amateur license, its 406 kHz B/W comfortably exceeding the FCC 100 kHz limit on the band, but FCC were okay with issuing an experimental license for it. As I read the FCC amateur regs emission spread spectrum emission modes such as CDMA can be used on all amateur bands as long as ITU emission designation symbols 2 and 3 are not both X. Such XX modes are designated by FCC as SS and only permitted above 420 MHz. 73 Trevor M5AKA ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
I am glad that the FCC considered this and granted the experimental license. You can simulate for all eternity but nothing replaces a real world test. By obtaining an FCC experimental license, the application with initial descriptive details become public record. The licensee then has the option of sharing with the amateur community or not. - Howie AB2S Date: Tue, 11 Mar 2014 22:14:33 + From: m5...@yahoo.co.uk Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR To: howied...@hotmail.com; amsat-bb@amsat.org This may be true if the owner of the satellite is not licensed in the USA or it is operating on some service other than the Amateur Radio Service. ITU recommends policy, it doesn't make or enforce law as I understand it. Judging from the number issued in recent years the FCC seem happy to issue experimental licenses for satellites in 144/435/2400 including the use of emission types that aren't covered by existing FCC amateur radio regulations. AggieSat4's 153.6 kbps 4 watt 436 MHz downlink using ITU Emission Designation 406KF7DBN might breach the bandwidth limits of an amateur license, its 406 kHz B/W comfortably exceeding the FCC 100 kHz limit on the band, but FCC were okay with issuing an experimental license for it. As I read the FCC amateur regs emission spread spectrum emission modes such as CDMA can be used on all amateur bands as long as ITU emission designation symbols 2 and 3 are not both X. Such XX modes are designated by FCC as SS and only permitted above 420 MHz. 73 Trevor M5AKA ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Hi Wouter, I personally agree with the ITU recommendations and think that CDMA/ spread spectrum techniques can be useful for amateur satellite communications. Unfortunately individual national regulatory entities (especially the U.S. FCC) can take a very long time to adopt ITU recommendations. Current FCC rules define three spreading sequences based on defined tapped linear sequence generators; one 7 bit, one 13 bit and one 19 bit. That makes it difficult to deploy an effective CDMA system. I am sure provisions could be made for a STA ( special temporary authority) but I would anticipate this to be an involved process. I believe the current efforts by the ARRL to give amateurs more flexibility by adopting maximum bandwidth restrictions vs maximum symbol rate restrictions is a move in the right direction. If the purpose of amateur radio is to advance the state of the art, the rules need to be flexible enough to accommodate innovation. Of course, these are just the opinions of one person. I am sure there are as many opinions as there are subscribers to this list :) And yes, politics can be a great attenuator to progress... Howie, AB2S Date: Sun, 9 Mar 2014 11:48:40 +0100 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: wouter...@gmail.com To: howied...@hotmail.com CC: damonwa4...@gmail.com; amsat-bb@amsat.org Howie, CDMA is actually actively promoted by the ITU. Indeed all the details have to be published before launch, so everyone can demodulate it. Citing from the ITU satellite-amateur handbook: Amateur and amateur-satellite systems should have technical characteristics that provide worldwide interoperability, and allow origination, relay and termination of communications independent of other radio services. Design emphasis should be placed on reliability, robustness and flexibility of reconfiguration for efficient emergency communications. Multiple access techniques (FDMA, TDMA and CDMA) should be selected for optimum spectrum efficiency and frequency reuse. The selection of modulation techniques should take into account resistance to interference and immunity to adverse propagation conditions. I have been researching this for the QB50 mission, but strong pressures (mainly from the US) within the project killed the idea early on. The US is now actively putting satellites in 70cm with experimental licenses, which unfortunately means they could use CDMA without providing the spreading codes. The (majority of the) rest of the world is still using the amateur satellite service. Using CDMA would be beneficial for sharing the spectrum, but required coordination as well. I was trying to standardize the parameters (for QB50), so the IARU could be handing out orthogonal codes to satellite teams, so avoid clashes. But welcome to politics. Wouter PA3WEG On Tue, Mar 4, 2014 at 10:16 PM, Howie DeFelice howied...@hotmail.com wrote: Yes, that is true, so are these licensed under an authority other than amateur radio ? If they aren't then my questions stand. Date: Tue, 4 Mar 2014 14:55:52 -0600 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: damonwa4...@gmail.com To: howied...@hotmail.com CC: amsat-bb@amsat.org 70 CM is not just for the ham bands, it is a shared band check the ruleswa4hfn Damon On Tue, Mar 4, 2014 at 2:30 PM, Howie DeFelice howied...@hotmail.com wrote: Is CDMA an authorized emission type for the Amateur service? What is the chipping rate/bandwidth of these? Don't the PRN sequences need to be made public so as not to be classified as encryption ? Detailed specs on the Sprites is in short supply. Has anyone done a link budget, seems like allot of spreading gain is required to hear 10mW form a 300km orbit which translates into allot of bandwidth in a part of the band usually reserved for narrow band modes. The lack of transparency on many of these projects that use the amateur bands seems to run against the spirit of amateur radio in my opinion. Howie AB2S ___ 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 ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Howie, CDMA is actually actively promoted by the ITU. Indeed all the details have to be published before launch, so everyone can demodulate it. Citing from the ITU satellite-amateur handbook: *Amateur and amateur-satellite systems should have technical characteristics that provide worldwide interoperability, and allow origination, relay and termination of communications independent of other radio services. Design emphasis should be placed on reliability, robustness and flexibility of reconfiguration for efficient emergency communications. Multiple access techniques (FDMA, TDMA and CDMA) should be selected for optimum spectrum efficiency and frequency reuse. The selection of modulation techniques should take into account resistance to interference and immunity to adverse propagation conditions.* I have been researching this for the QB50 mission, but strong pressures (mainly from the US) within the project killed the idea early on. The US is now actively putting satellites in 70cm with experimental licenses, which unfortunately means they could use CDMA without providing the spreading codes. The (majority of the) rest of the world is still using the amateur satellite service. Using CDMA would be beneficial for sharing the spectrum, but required coordination as well. I was trying to standardize the parameters (for QB50), so the IARU could be handing out orthogonal codes to satellite teams, so avoid clashes. But welcome to politics. Wouter PA3WEG On Tue, Mar 4, 2014 at 10:16 PM, Howie DeFelice howied...@hotmail.comwrote: Yes, that is true, so are these licensed under an authority other than amateur radio ? If they aren't then my questions stand. Date: Tue, 4 Mar 2014 14:55:52 -0600 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: damonwa4...@gmail.com To: howied...@hotmail.com CC: amsat-bb@amsat.org 70 CM is not just for the ham bands, it is a shared band check the ruleswa4hfn Damon On Tue, Mar 4, 2014 at 2:30 PM, Howie DeFelice howied...@hotmail.com wrote: Is CDMA an authorized emission type for the Amateur service? What is the chipping rate/bandwidth of these? Don't the PRN sequences need to be made public so as not to be classified as encryption ? Detailed specs on the Sprites is in short supply. Has anyone done a link budget, seems like allot of spreading gain is required to hear 10mW form a 300km orbit which translates into allot of bandwidth in a part of the band usually reserved for narrow band modes. The lack of transparency on many of these projects that use the amateur bands seems to run against the spirit of amateur radio in my opinion. Howie AB2S ___ 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 ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
As I see it there's no absolute guarantee that any satellite won't become an orbital hazard at some point. The debris from weapons testing in space can generate hundreds of thousands of fragments but the biggest hazard is natural debris - there are tens of millions of natural debris fragments in Earth orbit. 73 Trevor M5AKA On Tuesday, 4 March 2014, 2:06, B J va6...@gmail.com wrote: On 3/4/14, M5AKA m5...@yahoo.co.uk wrote: Launch of Two Hundred 437 MHz Satellites http://amsat-uk.org/2014/03/03/launch-of-two-hundred-437-mhz-satellites/ Southampton University Wireless Society WebSDR Tracks LitSat-1 http://amsat-uk.org/2014/03/04/southampton-university-wireless-society-websdr/ RSGB: IARU 2014 VHF/UHF/UW Consultation http://amsat-uk.org/2014/03/02/rsgb-iaru-2014-vhfuhfuw-consultation/ Considering that space debris is a major concern, what guarantees are there that some of these birds won't become orbital hazards? (Yes, I'm well aware that many of them won't be out there for very long, but re-entry can't always be accurately predicted.) 73s Bernhard VA6BMJ @ DO33FL ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Is CDMA an authorized emission type for the Amateur service? What is the chipping rate/bandwidth of these? Don't the PRN sequences need to be made public so as not to be classified as encryption ? Detailed specs on the Sprites is in short supply. Has anyone done a link budget, seems like allot of spreading gain is required to hear 10mW form a 300km orbit which translates into allot of bandwidth in a part of the band usually reserved for narrow band modes. The lack of transparency on many of these projects that use the amateur bands seems to run against the spirit of amateur radio in my opinion. Howie AB2S ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
70 CM is not just for the ham bands, it is a shared band check the rules wa4hfn Damon On Tue, Mar 4, 2014 at 2:30 PM, Howie DeFelice howied...@hotmail.comwrote: Is CDMA an authorized emission type for the Amateur service? What is the chipping rate/bandwidth of these? Don't the PRN sequences need to be made public so as not to be classified as encryption ? Detailed specs on the Sprites is in short supply. Has anyone done a link budget, seems like allot of spreading gain is required to hear 10mW form a 300km orbit which translates into allot of bandwidth in a part of the band usually reserved for narrow band modes. The lack of transparency on many of these projects that use the amateur bands seems to run against the spirit of amateur radio in my opinion. Howie AB2S ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
Yes, that is true, so are these licensed under an authority other than amateur radio ? If they aren't then my questions stand. Date: Tue, 4 Mar 2014 14:55:52 -0600 Subject: Re: [amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR From: damonwa4...@gmail.com To: howied...@hotmail.com CC: amsat-bb@amsat.org 70 CM is not just for the ham bands, it is a shared band check the ruleswa4hfn Damon On Tue, Mar 4, 2014 at 2:30 PM, Howie DeFelice howied...@hotmail.com wrote: Is CDMA an authorized emission type for the Amateur service? What is the chipping rate/bandwidth of these? Don't the PRN sequences need to be made public so as not to be classified as encryption ? Detailed specs on the Sprites is in short supply. Has anyone done a link budget, seems like allot of spreading gain is required to hear 10mW form a 300km orbit which translates into allot of bandwidth in a part of the band usually reserved for narrow band modes. The lack of transparency on many of these projects that use the amateur bands seems to run against the spirit of amateur radio in my opinion. Howie AB2S ___ 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
[amsat-bb] Re: Two hundred 437 MHz satallites launch March 16 + WebSDR
On 3/4/14, M5AKA m5...@yahoo.co.uk wrote: Launch of Two Hundred 437 MHz Satellites http://amsat-uk.org/2014/03/03/launch-of-two-hundred-437-mhz-satellites/ Southampton University Wireless Society WebSDR Tracks LitSat-1 http://amsat-uk.org/2014/03/04/southampton-university-wireless-society-websdr/ RSGB: IARU 2014 VHF/UHF/UW Consultation http://amsat-uk.org/2014/03/02/rsgb-iaru-2014-vhfuhfuw-consultation/ Considering that space debris is a major concern, what guarantees are there that some of these birds won't become orbital hazards? (Yes, I'm well aware that many of them won't be out there for very long, but re-entry can't always be accurately predicted.) 73s Bernhard VA6BMJ @ DO33FL ___ 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
