Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Hi, I am interested in your new GPSDO. How do I find out more about buying the kit? Is this a USA only deal? cheers, Neville Michie Sydney, Australia On 18/10/2014, at 9:35 AM, S. Jackson via time-nuts wrote: > "LTE Lite GPSDO" ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
No worries Pete! if someone doesn't think its for them, then no big deal and they can move on hopefully without making others feel uncomfortable. That's the beauty of capitalism: we can make free choices and there are so many of them to make, and those who try to sell the wrong, or overpriced goods/services (hopefully) go out of business eventually. Bye, Said In a message dated 10/17/2014 19:52:30 Pacific Daylight Time, p...@petelancashire.com writes: No where did I mention comparing specifications. It was a statement of an individual Joe being able to get a GPDSO for a very reasonable amount. Just a usable GPDSO nothing else. On Fri, Oct 17, 2014 at 6:14 PM, Bob Camp wrote: > Hi > > The question on all of these setups is very much - what do you need? > > The T-Bolt was designed to meet some very specific requirements. It’s got > an OCXO onboard because of that. > > A 48 hour battery backed Rb does something very different, it’s got > different costs associated with it. > > A modern / up to date TCXO based unit makes some compromises to trade off > against power and size. > > Depending on what your system needs are, each of the first two may > uniquely fill a bill that the others will not and can not. If you need to > run 120 days on battery, the third will win the contest easily. If you want > to run on something other than GPS, number 3 is your choice. > > Cost wise, it all depends on when you bought what. I have Rb’s that cost > less than $40 and T-Bolts that cost less than $100. You can still get > surplus T-Bolt like objects (OCXO based surplus GPSDO’s) for under $130. I > also have some stuff I’ve bought on eBay (and other surplus outlets) over > the years that turned out to be less than perfect. Depending on surplus > gear in a commercial system would be silly compared to using newly > manufactured parts. It all depends on what you need. > > Bob > > > On Oct 17, 2014, at 5:19 PM, paul swed wrote: > > > > Don't want to hijack any discussion and am looking forward to the ebay > site > > and ordering. Whats amazing is the power spec in addition to other > specs. I > > rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 > > watts just idling along and keeping two hefty SLA batteries charged for a > > 48 hour run time if needed. > > > > I can clearly see the case of careful support system design such that a > > battery set can be charged and even in a power failure run several days > on > > a small battery. > > SLA 7 amp was something like 100 plus hours. Bert introduced me to some > of > > the Lithium battery technologies that can be had for reasonable cost and > > are small and dense. > > > > But that said really no need for a battery since restarts are fast... > > Lots to think about. Like LEDs drawing more power then the system and > > sloppy base power supplies wasting power. > > Regards > > Paul > > WB8TSL > > > > On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire < > p...@petelancashire.com> > > wrote: > > > >> Sorry to create any misunderstanding > >> > >> I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for > >> doing what they did for the group > >> > >> I was in no way comparing the used Thunderbolts to the LTE Lite. > >> > >> -pete > >> > >> On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: > >> > >>> And, somehow I expect that my LTE-LITE will actually work, which my > >>> thunderbolt never did. (Very noisy) It continues to collect dust > >>> On 10/17/2014 3:49 PM, Pete Lancashire wrote: > >>> > First three cheers to LTE for making these available. > > It reminds me when Motorola made a developers kit for the then > new 68HC11 MCU available for $68.11. > > I know of one design win they got that more then made of their > marketing > costs. > > Another that hit me is with inflation the LTE Lite is not much more > then > what many of us paid for our Thunderbolts. > > For those new to the list ... > > https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > > http://www.leapsecond.com/pages/tapr-tbolt/ > > In 2008, $124, the LTE Lite in 2014 $195. > > With 'real' inflation (not the 11% you get online) the $71 difference > is > not much more. > > My two backup Thunderbolts cost me $145 each, just before they hit > $200 > then became history. > > Again thanks to Said and JLT > > -pete > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > > > >>> > >>> --- > >>> This email is free from viruses and malware because avast! Antivirus > >>> protection is active. > >>> http://www.avast.com > >>> > >
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
No where did I mention comparing specifications. It was a statement of an individual Joe being able to get a GPDSO for a very reasonable amount. Just a usable GPDSO nothing else. On Fri, Oct 17, 2014 at 6:14 PM, Bob Camp wrote: > Hi > > The question on all of these setups is very much - what do you need? > > The T-Bolt was designed to meet some very specific requirements. It’s got > an OCXO onboard because of that. > > A 48 hour battery backed Rb does something very different, it’s got > different costs associated with it. > > A modern / up to date TCXO based unit makes some compromises to trade off > against power and size. > > Depending on what your system needs are, each of the first two may > uniquely fill a bill that the others will not and can not. If you need to > run 120 days on battery, the third will win the contest easily. If you want > to run on something other than GPS, number 3 is your choice. > > Cost wise, it all depends on when you bought what. I have Rb’s that cost > less than $40 and T-Bolts that cost less than $100. You can still get > surplus T-Bolt like objects (OCXO based surplus GPSDO’s) for under $130. I > also have some stuff I’ve bought on eBay (and other surplus outlets) over > the years that turned out to be less than perfect. Depending on surplus > gear in a commercial system would be silly compared to using newly > manufactured parts. It all depends on what you need. > > Bob > > > On Oct 17, 2014, at 5:19 PM, paul swed wrote: > > > > Don't want to hijack any discussion and am looking forward to the ebay > site > > and ordering. Whats amazing is the power spec in addition to other > specs. I > > rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 > > watts just idling along and keeping two hefty SLA batteries charged for a > > 48 hour run time if needed. > > > > I can clearly see the case of careful support system design such that a > > battery set can be charged and even in a power failure run several days > on > > a small battery. > > SLA 7 amp was something like 100 plus hours. Bert introduced me to some > of > > the Lithium battery technologies that can be had for reasonable cost and > > are small and dense. > > > > But that said really no need for a battery since restarts are fast... > > Lots to think about. Like LEDs drawing more power then the system and > > sloppy base power supplies wasting power. > > Regards > > Paul > > WB8TSL > > > > On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire < > p...@petelancashire.com> > > wrote: > > > >> Sorry to create any misunderstanding > >> > >> I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for > >> doing what they did for the group > >> > >> I was in no way comparing the used Thunderbolts to the LTE Lite. > >> > >> -pete > >> > >> On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: > >> > >>> And, somehow I expect that my LTE-LITE will actually work, which my > >>> thunderbolt never did. (Very noisy) It continues to collect dust > >>> On 10/17/2014 3:49 PM, Pete Lancashire wrote: > >>> > First three cheers to LTE for making these available. > > It reminds me when Motorola made a developers kit for the then > new 68HC11 MCU available for $68.11. > > I know of one design win they got that more then made of their > marketing > costs. > > Another that hit me is with inflation the LTE Lite is not much more > then > what many of us paid for our Thunderbolts. > > For those new to the list ... > > https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > > http://www.leapsecond.com/pages/tapr-tbolt/ > > In 2008, $124, the LTE Lite in 2014 $195. > > With 'real' inflation (not the 11% you get online) the $71 difference > is > not much more. > > My two backup Thunderbolts cost me $145 each, just before they hit > $200 > then became history. > > Again thanks to Said and JLT > > -pete > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > > > >>> > >>> --- > >>> This email is free from viruses and malware because avast! Antivirus > >>> protection is active. > >>> http://www.avast.com > >>> > >>> ___ > >>> time-nuts mailing list -- time-nuts@febo.com > >>> To unsubscribe, go to https://www.febo.com/cgi-bin/ > >>> mailman/listinfo/time-nuts > >>> and follow the instructions there. > >>> > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > ___ > > time-nuts mailing list -- time-nu
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
I'm sorry for what I wrote -pete bye ... On Fri, Oct 17, 2014 at 7:46 PM, Pete Lancashire wrote: > No where did I mention comparing specifications. > > It was a statement of an individual Joe being able to get a GPDSO for a > very reasonable amount. > > > Just a usable GPDSO nothing else. > > > > On Fri, Oct 17, 2014 at 6:14 PM, Bob Camp wrote: > >> Hi >> >> The question on all of these setups is very much - what do you need? >> >> The T-Bolt was designed to meet some very specific requirements. It’s got >> an OCXO onboard because of that. >> >> A 48 hour battery backed Rb does something very different, it’s got >> different costs associated with it. >> >> A modern / up to date TCXO based unit makes some compromises to trade off >> against power and size. >> >> Depending on what your system needs are, each of the first two may >> uniquely fill a bill that the others will not and can not. If you need to >> run 120 days on battery, the third will win the contest easily. If you want >> to run on something other than GPS, number 3 is your choice. >> >> Cost wise, it all depends on when you bought what. I have Rb’s that cost >> less than $40 and T-Bolts that cost less than $100. You can still get >> surplus T-Bolt like objects (OCXO based surplus GPSDO’s) for under $130. I >> also have some stuff I’ve bought on eBay (and other surplus outlets) over >> the years that turned out to be less than perfect. Depending on surplus >> gear in a commercial system would be silly compared to using newly >> manufactured parts. It all depends on what you need. >> >> Bob >> >> > On Oct 17, 2014, at 5:19 PM, paul swed wrote: >> > >> > Don't want to hijack any discussion and am looking forward to the ebay >> site >> > and ordering. Whats amazing is the power spec in addition to other >> specs. I >> > rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 >> > watts just idling along and keeping two hefty SLA batteries charged for >> a >> > 48 hour run time if needed. >> > >> > I can clearly see the case of careful support system design such that a >> > battery set can be charged and even in a power failure run several days >> on >> > a small battery. >> > SLA 7 amp was something like 100 plus hours. Bert introduced me to some >> of >> > the Lithium battery technologies that can be had for reasonable cost and >> > are small and dense. >> > >> > But that said really no need for a battery since restarts are fast... >> > Lots to think about. Like LEDs drawing more power then the system and >> > sloppy base power supplies wasting power. >> > Regards >> > Paul >> > WB8TSL >> > >> > On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire < >> p...@petelancashire.com> >> > wrote: >> > >> >> Sorry to create any misunderstanding >> >> >> >> I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for >> >> doing what they did for the group >> >> >> >> I was in no way comparing the used Thunderbolts to the LTE Lite. >> >> >> >> -pete >> >> >> >> On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford >> wrote: >> >> >> >>> And, somehow I expect that my LTE-LITE will actually work, which my >> >>> thunderbolt never did. (Very noisy) It continues to collect dust >> >>> On 10/17/2014 3:49 PM, Pete Lancashire wrote: >> >>> >> First three cheers to LTE for making these available. >> >> It reminds me when Motorola made a developers kit for the then >> new 68HC11 MCU available for $68.11. >> >> I know of one design win they got that more then made of their >> marketing >> costs. >> >> Another that hit me is with inflation the LTE Lite is not much more >> then >> what many of us paid for our Thunderbolts. >> >> For those new to the list ... >> >> https://www.febo.com/pipermail/time-nuts/2008-May/031100.html >> >> http://www.leapsecond.com/pages/tapr-tbolt/ >> >> In 2008, $124, the LTE Lite in 2014 $195. >> >> With 'real' inflation (not the 11% you get online) the $71 >> difference is >> not much more. >> >> My two backup Thunderbolts cost me $145 each, just before they hit >> $200 >> then became history. >> >> Again thanks to Said and JLT >> >> -pete >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> >>> >> >>> --- >> >>> This email is free from viruses and malware because avast! Antivirus >> >>> protection is active. >> >>> http://www.avast.com >> >>> >> >>> ___ >> >>> time-nuts mailing list -- time-nuts@febo.com >> >>> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> >>> mailman/listinfo/time-nuts >> >>> and follow the instructions there. >> >>> >> >> ___ >> >> time-nuts mailing
[time-nuts] Fwd: Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Bob, "Depending on surplus gear in a commercial system would be silly compared to using newly manufactured parts." You nailed it Bob, we wouldn't compare an old 2004 Porsche Cayenne one can now get for $5K with a new Tata car costing $6K either.. Both get you there for almost the same price even though the Porsche is about 20x more expensive new, but you can't and shouldn't compare the performance of the two. They were designed for two completely different applications, and there is a reason why the Porsche (Thunderbolt) new is significantly more expensive - it has significantly higher performance. Its a silly comparison. bye, Said Reply-To: Discussion of precise time and frequency measurement <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > Hi The question on all of these setups is very much - what do you need? The T-Bolt was designed to meet some very specific requirements. It’s got an OCXO onboard because of that. A 48 hour battery backed Rb does something very different, it’s got different costs associated with it. A modern / up to date TCXO based unit makes some compromises to trade off against power and size. Depending on what your system needs are, each of the first two may uniquely fill a bill that the others will not and can not. If you need to run 120 days on battery, the third will win the contest easily. If you want to run on something other than GPS, number 3 is your choice. Cost wise, it all depends on when you bought what. I have Rb’s that cost less than $40 and T-Bolts that cost less than $100. You can still get surplus T-Bolt like objects (OCXO based surplus GPSDO’s) for under $130. I also have some stuff I’ve bought on eBay (and other surplus outlets) over the years that turned out to be less than perfect. Depending on surplus gear in a commercial system would be silly compared to using newly manufactured parts. It all depends on what you need. Bob On Oct 17, 2014, at 5:19 PM, paul swed <_paulswedb@gmail.com_ (mailto:paulsw...@gmail.com) > wrote: Don't want to hijack any discussion and am looking forward to the ebay site and ordering. Whats amazing is the power spec in addition to other specs. I rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 watts just idling along and keeping two hefty SLA batteries charged for a 48 hour run time if needed. I can clearly see the case of careful support system design such that a battery set can be charged and even in a power failure run several days on a small battery. SLA 7 amp was something like 100 plus hours. Bert introduced me to some of the Lithium battery technologies that can be had for reasonable cost and are small and dense. But that said really no need for a battery since restarts are fast... Lots to think about. Like LEDs drawing more power then the system and sloppy base power supplies wasting power. Regards Paul WB8TSL On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire <_pete@petelancashire.com_ (mailto:p...@petelancashire.com) > wrote: Sorry to create any misunderstanding I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for doing what they did for the group I was in no way comparing the used Thunderbolts to the LTE Lite. -pete On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford <_wb4gcs@wb4gcs.org_ (mailto:wb4...@wb4gcs.org) > wrote: And, somehow I expect that my LTE-LITE will actually work, which my thunderbolt never did. (Very noisy) It continues to collect dust On 10/17/2014 3:49 PM, Pete Lancashire wrote: First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto:time-nuts@febo.com) To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
John, I used John Miles Timepod and associated application software, now available from Microsemi, and highly recommended. I fed the output of the DFF directly into the timepod (via a DC-block and 33 Ohms series resistor). The reference was an HP 58503A GPSDO which limits the noise floor of the measurement a bit. bye, Said In a message dated 10/17/2014 18:45:11 Pacific Daylight Time, j...@westmorelandengineering.com writes: Said, What tool(s) did you use to generate that data and output the graph? Thanks, John On Fri, Oct 17, 2014 at 6:10 PM, S. Jackson via time-nuts < time-nuts@febo.com> wrote: > Jim, > > Here is the resulting 10MHz phase noise plot from the 20MHz TCXO output: > > > In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, > saidj...@aol.com writes: > > > Hello Jim, > let me answer through Time Nuts as this may interest other parties as > well. > Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V > CMOS output from the LTE-Lite module will preserve the phase noise > (actually > improve it by up to 6dB due to the 20log(n/m) noise improvement) and will > not add any spurs if you use the clean 3.0V output from the LTE-Lite > module > or an external clean power supply (please note the LTE-Lite TCXO RF output > is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the > TCXO and buffer). > Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on > our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and > using a fast CMOS divider will result in additive phase noise that will be > below the crystal oscillator phase noise floor. > That will result in significantly better phase noise and much lower spurs > than using the synthesized 10MHz output from the board, and one 74' chip > can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is > exactly what we would do here if we needed a clean 10MHz from the 20MHz > LTE-Lite board. > I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel > already packaged-up and connectorized as well. > Hope that helps, > Said > Hi Said > I was one of those looking for 10Mhz but I just thought again now that it > might be just as well to divide the standard 20Mhz output by 2 using a FF. > I think that would preserve all the desirable characteristics of the 20Mhz > signal which I understand to just be square wave at CMOS 3.3v levels > anyway. Is that correct? > Thanks > Jim > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
Said, What tool(s) did you use to generate that data and output the graph? Thanks, John On Fri, Oct 17, 2014 at 6:10 PM, S. Jackson via time-nuts < time-nuts@febo.com> wrote: > Jim, > > Here is the resulting 10MHz phase noise plot from the 20MHz TCXO output: > > > In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, > saidj...@aol.com writes: > > > Hello Jim, > let me answer through Time Nuts as this may interest other parties as > well. > Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V > CMOS output from the LTE-Lite module will preserve the phase noise > (actually > improve it by up to 6dB due to the 20log(n/m) noise improvement) and will > not add any spurs if you use the clean 3.0V output from the LTE-Lite > module > or an external clean power supply (please note the LTE-Lite TCXO RF output > is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the > TCXO and buffer). > Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on > our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and > using a fast CMOS divider will result in additive phase noise that will be > below the crystal oscillator phase noise floor. > That will result in significantly better phase noise and much lower spurs > than using the synthesized 10MHz output from the board, and one 74' chip > can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is > exactly what we would do here if we needed a clean 10MHz from the 20MHz > LTE-Lite board. > I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel > already packaged-up and connectorized as well. > Hope that helps, > Said > Hi Said > I was one of those looking for 10Mhz but I just thought again now that it > might be just as well to divide the standard 20Mhz output by 2 using a FF. > I think that would preserve all the desirable characteristics of the 20Mhz > signal which I understand to just be square wave at CMOS 3.3v levels > anyway. Is that correct? > Thanks > Jim > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
Some photos of the divider module I built: In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, saidj...@aol.com writes: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
Jim, Here is the resulting 10MHz phase noise plot from the 20MHz TCXO output: In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, saidj...@aol.com writes: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim LTE_10MHz_divide-by-2_PN.png Description: Binary data ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
Jim, et. al., I spent some time today and put together a Divide-by-2 circuit. Attached are the schematics, I will send some photos in additional mails so we don't overload the mail system. Some comments: * I grab the 3.0V from capacitor C6 on the eval board. That is the low-noise filtered analog supply. By loading it with the FF, that voltage goes down to 2.86V.. Using the digital 3.3V supply resulted in excessive spurs. * I used only two additional components: a cap and a series resistor * The IC I used was an old Fairchild 74LVX74 SO-14 chip I had laying around * Notice the nice improvement in phase noise, and the absence of any measurable spurs * Notice the nice 6dB phase noise improvement compared to using the direct outptut, even the floor improved to close to my reference noise floor, so theory meets practice * I spent less than 45 minutes building this on a small copper-clad board, using the ground of the board as much as possible * The output power of the 74LVC74 driving the 50 Ohms input impedance of the analyzer is pretty low, less than 7dBm, so a nice buffer would help * Notice how I set the Q output of the unused FF to 0V, and then connect that pin to ground to use it as an additional ground pin * While I wired up the 3.0V power to the eval board, I did not even bother wiring up the ground. I simply used the coax cables as DC ground return * The LTE-Lite board was powered from a Thinkpad PC via USB cable, and disciplining to GPS so I did not even use an external low-noise isolated 5V lab supply or anything like that, just the noise PC's USB port. Bye, Said In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, saidj...@aol.com writes: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Hi The question on all of these setups is very much - what do you need? The T-Bolt was designed to meet some very specific requirements. It’s got an OCXO onboard because of that. A 48 hour battery backed Rb does something very different, it’s got different costs associated with it. A modern / up to date TCXO based unit makes some compromises to trade off against power and size. Depending on what your system needs are, each of the first two may uniquely fill a bill that the others will not and can not. If you need to run 120 days on battery, the third will win the contest easily. If you want to run on something other than GPS, number 3 is your choice. Cost wise, it all depends on when you bought what. I have Rb’s that cost less than $40 and T-Bolts that cost less than $100. You can still get surplus T-Bolt like objects (OCXO based surplus GPSDO’s) for under $130. I also have some stuff I’ve bought on eBay (and other surplus outlets) over the years that turned out to be less than perfect. Depending on surplus gear in a commercial system would be silly compared to using newly manufactured parts. It all depends on what you need. Bob > On Oct 17, 2014, at 5:19 PM, paul swed wrote: > > Don't want to hijack any discussion and am looking forward to the ebay site > and ordering. Whats amazing is the power spec in addition to other specs. I > rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 > watts just idling along and keeping two hefty SLA batteries charged for a > 48 hour run time if needed. > > I can clearly see the case of careful support system design such that a > battery set can be charged and even in a power failure run several days on > a small battery. > SLA 7 amp was something like 100 plus hours. Bert introduced me to some of > the Lithium battery technologies that can be had for reasonable cost and > are small and dense. > > But that said really no need for a battery since restarts are fast... > Lots to think about. Like LEDs drawing more power then the system and > sloppy base power supplies wasting power. > Regards > Paul > WB8TSL > > On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire > wrote: > >> Sorry to create any misunderstanding >> >> I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for >> doing what they did for the group >> >> I was in no way comparing the used Thunderbolts to the LTE Lite. >> >> -pete >> >> On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: >> >>> And, somehow I expect that my LTE-LITE will actually work, which my >>> thunderbolt never did. (Very noisy) It continues to collect dust >>> On 10/17/2014 3:49 PM, Pete Lancashire wrote: >>> First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. >>> >>> --- >>> This email is free from viruses and malware because avast! Antivirus >>> protection is active. >>> http://www.avast.com >>> >>> ___ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/ >>> mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
And lastly the entire setup as tested: In a message dated 10/17/2014 11:32:49 Pacific Daylight Time, saidj...@aol.com writes: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5370 extender boards
I'll just echo. 5370 boards very pro and a bargain. Nice mindless job to put together, a break from trying to get a dual boot win7/linux mint compuetr going. pfui. Don paul swed > I wasn't going to post but Like Bill I received my 5370 and TM500 boards > yesterday. That was fast and agree with the quality. A nice add for the TM > 500 is the use of ribbon cable sockets and ribbon cables that will > accelerate assembly dramatically. > Was dreading the ribbon cable trimming and soldering. > Regards > Paul > WB8TSL > > On Fri, Oct 17, 2014 at 4:36 PM, BIll Ezell wrote: > >> I just got my extender board kit, just want to say the board quality is >> great. I have to give kudos to M.S., very quick ship, perfect. Now if I >> could just figure out how to adjust those pots on the input board without >> having a screwdriver that's 0.5" long, I'd be all set. :) >> >> -- >> Bill Ezell >> -- >> The day Microsoft makes something that doesn't suck >> will be the day they make vacuum cleaners. >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > -- "The power of accurate observation is commonly called cynicism by those who have not got it." -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 5370 extender boards
I wasn't going to post but Like Bill I received my 5370 and TM500 boards yesterday. That was fast and agree with the quality. A nice add for the TM 500 is the use of ribbon cable sockets and ribbon cables that will accelerate assembly dramatically. Was dreading the ribbon cable trimming and soldering. Regards Paul WB8TSL On Fri, Oct 17, 2014 at 4:36 PM, BIll Ezell wrote: > I just got my extender board kit, just want to say the board quality is > great. I have to give kudos to M.S., very quick ship, perfect. Now if I > could just figure out how to adjust those pots on the input board without > having a screwdriver that's 0.5" long, I'd be all set. :) > > -- > Bill Ezell > -- > The day Microsoft makes something that doesn't suck > will be the day they make vacuum cleaners. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Hello Paul, thanks much, we sent out notice early today to the folks on our list that the Ebay store is up and running, and units are selling already. You can search for "LTE Lite GPSDO" and you will find it there. Your email was also on that distributor.. The power spec is actually ~160mW for the LTE-Lite module itself not 1/16W (we wish!). Please note that the LTE Eval kit has some additional circuitry on it (a USB interface chip, a bunch of LED's, and two voltage regulators) so the Eval kit power consumption is slightly higher than the LTE-Lite SMT module by itself, but you are right having the entire GPSDO consume only about ~0.2W is certainly nice. We did use a linear regulator to go from 5V to 3.3V on the eval board so that is somewhat wasteful, but alas more quiet. Here is a fun fact: we used an active HP GPS two-to-one antenna splitter to test out two boards. One board was powered up through USB, the second board was supposed to be turned-off. Both boards lit up and worked like a charm to our amusement, turns out the antenna power coming from one board supplied enough backwards power through the splitter to make the second board work perfectly just from that antenna feed.. That mode of operation is not advised of course, but its possible. bye, Said In a message dated 10/17/2014 15:20:51 Pacific Daylight Time, paulsw...@gmail.com writes: Don't want to hijack any discussion and am looking forward to the ebay site and ordering. Whats amazing is the power spec in addition to other specs. I rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 watts just idling along and keeping two hefty SLA batteries charged for a 48 hour run time if needed. I can clearly see the case of careful support system design such that a battery set can be charged and even in a power failure run several days on a small battery. SLA 7 amp was something like 100 plus hours. Bert introduced me to some of the Lithium battery technologies that can be had for reasonable cost and are small and dense. But that said really no need for a battery since restarts are fast... Lots to think about. Like LEDs drawing more power then the system and sloppy base power supplies wasting power. Regards Paul WB8TSL On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire wrote: > Sorry to create any misunderstanding > > I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for > doing what they did for the group > > I was in no way comparing the used Thunderbolts to the LTE Lite. > > -pete > > On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: > > > And, somehow I expect that my LTE-LITE will actually work, which my > > thunderbolt never did. (Very noisy) It continues to collect dust > > On 10/17/2014 3:49 PM, Pete Lancashire wrote: > > > >> First three cheers to LTE for making these available. > >> > >> It reminds me when Motorola made a developers kit for the then > >> new 68HC11 MCU available for $68.11. > >> > >> I know of one design win they got that more then made of their marketing > >> costs. > >> > >> Another that hit me is with inflation the LTE Lite is not much more then > >> what many of us paid for our Thunderbolts. > >> > >> For those new to the list ... > >> > >> https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > >> > >> http://www.leapsecond.com/pages/tapr-tbolt/ > >> > >> In 2008, $124, the LTE Lite in 2014 $195. > >> > >> With 'real' inflation (not the 11% you get online) the $71 difference is > >> not much more. > >> > >> My two backup Thunderbolts cost me $145 each, just before they hit $200 > >> then became history. > >> > >> Again thanks to Said and JLT > >> > >> -pete > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to https://www.febo.com/cgi-bin/ > >> mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > >> > > > > --- > > This email is free from viruses and malware because avast! Antivirus > > protection is active. > > http://www.avast.com > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > mailman/listinfo/time-nuts > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follo
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Don't want to hijack any discussion and am looking forward to the ebay site and ordering. Whats amazing is the power spec in addition to other specs. I rechecked the spec 1/16th watt at 3.3V. My RB in the basement draws 24 watts just idling along and keeping two hefty SLA batteries charged for a 48 hour run time if needed. I can clearly see the case of careful support system design such that a battery set can be charged and even in a power failure run several days on a small battery. SLA 7 amp was something like 100 plus hours. Bert introduced me to some of the Lithium battery technologies that can be had for reasonable cost and are small and dense. But that said really no need for a battery since restarts are fast... Lots to think about. Like LEDs drawing more power then the system and sloppy base power supplies wasting power. Regards Paul WB8TSL On Fri, Oct 17, 2014 at 4:53 PM, Pete Lancashire wrote: > Sorry to create any misunderstanding > > I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for > doing what they did for the group > > I was in no way comparing the used Thunderbolts to the LTE Lite. > > -pete > > On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: > > > And, somehow I expect that my LTE-LITE will actually work, which my > > thunderbolt never did. (Very noisy) It continues to collect dust > > On 10/17/2014 3:49 PM, Pete Lancashire wrote: > > > >> First three cheers to LTE for making these available. > >> > >> It reminds me when Motorola made a developers kit for the then > >> new 68HC11 MCU available for $68.11. > >> > >> I know of one design win they got that more then made of their marketing > >> costs. > >> > >> Another that hit me is with inflation the LTE Lite is not much more then > >> what many of us paid for our Thunderbolts. > >> > >> For those new to the list ... > >> > >> https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > >> > >> http://www.leapsecond.com/pages/tapr-tbolt/ > >> > >> In 2008, $124, the LTE Lite in 2014 $195. > >> > >> With 'real' inflation (not the 11% you get online) the $71 difference is > >> not much more. > >> > >> My two backup Thunderbolts cost me $145 each, just before they hit $200 > >> then became history. > >> > >> Again thanks to Said and JLT > >> > >> -pete > >> ___ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to https://www.febo.com/cgi-bin/ > >> mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > >> > > > > --- > > This email is free from viruses and malware because avast! Antivirus > > protection is active. > > http://www.avast.com > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to https://www.febo.com/cgi-bin/ > > mailman/listinfo/time-nuts > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] 5370 extender boards
I just got my extender board kit, just want to say the board quality is great. I have to give kudos to M.S., very quick ship, perfect. Now if I could just figure out how to adjust those pots on the input board without having a screwdriver that's 0.5" long, I'd be all set. :) -- Bill Ezell -- The day Microsoft makes something that doesn't suck will be the day they make vacuum cleaners. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Sorry to create any misunderstanding I was saying thanks to TVB/TAPR for all their effort, and Said/JLT for doing what they did for the group I was in no way comparing the used Thunderbolts to the LTE Lite. -pete On Fri, Oct 17, 2014 at 1:13 PM, Jim Sanford wrote: > And, somehow I expect that my LTE-LITE will actually work, which my > thunderbolt never did. (Very noisy) It continues to collect dust > On 10/17/2014 3:49 PM, Pete Lancashire wrote: > >> First three cheers to LTE for making these available. >> >> It reminds me when Motorola made a developers kit for the then >> new 68HC11 MCU available for $68.11. >> >> I know of one design win they got that more then made of their marketing >> costs. >> >> Another that hit me is with inflation the LTE Lite is not much more then >> what many of us paid for our Thunderbolts. >> >> For those new to the list ... >> >> https://www.febo.com/pipermail/time-nuts/2008-May/031100.html >> >> http://www.leapsecond.com/pages/tapr-tbolt/ >> >> In 2008, $124, the LTE Lite in 2014 $195. >> >> With 'real' inflation (not the 11% you get online) the $71 difference is >> not much more. >> >> My two backup Thunderbolts cost me $145 each, just before they hit $200 >> then became history. >> >> Again thanks to Said and JLT >> >> -pete >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. > http://www.avast.com > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Was just comparing what was available to 'time nuts' in recent history, not the commercial market. Technology, marches on !! -pete On Fri, Oct 17, 2014 at 1:13 PM, S. Jackson via time-nuts < time-nuts@febo.com> wrote: > Pete, > > that is not inflation, that is supply and demand. The Trimble Mini-T was > priced at $945 on Trimble's standard price list for 1 to 9 pieces, and the > Thunderbolt was likely twice that much when sold new, so you have to > compare > that to the LTE-Lite pricing. > > The Thunderbolt units offered by Tom via TAPR to Time Nuts at that time > were old rejects that had done their duty already, were fully paid-off and > would have been scrapped and recycled by the Telecom otherwise, and Tom > invested a huge amount of his time testing them and packaging/shipping > them at > no charge, so that pricing was completely random and lucky for us to be at > the right time at the right moment. > > In fact the complete used Thunderbolt package now lists for up to $498 on > Ebay.. > > No problem on offering these kits factory-new with warranty at what we > hope is a fair price, > Bye, > Said > > > In a message dated 10/17/2014 12:49:32 Pacific Daylight Time, > p...@petelancashire.com writes: > > First three cheers to LTE for making these available. > > It reminds me when Motorola made a developers kit for the then > new 68HC11 MCU available for $68.11. > > I know of one design win they got that more then made of their marketing > costs. > > Another that hit me is with inflation the LTE Lite is not much more then > what many of us paid for our Thunderbolts. > > For those new to the list ... > > https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > > http://www.leapsecond.com/pages/tapr-tbolt/ > > In 2008, $124, the LTE Lite in 2014 $195. > > With 'real' inflation (not the 11% you get online) the $71 difference is > not much more. > > My two backup Thunderbolts cost me $145 each, just before they hit $200 > then became history. > > Again thanks to Said and JLT > > -pete > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
How do you feel your module compares to that old Thunderbolt, Said? NS On Fri, Oct 17, 2014 at 1:13 PM, S. Jackson via time-nuts < time-nuts@febo.com> wrote: > Pete, > > that is not inflation, that is supply and demand. The Trimble Mini-T was > priced at $945 on Trimble's standard price list for 1 to 9 pieces, and the > Thunderbolt was likely twice that much when sold new, so you have to > compare > that to the LTE-Lite pricing. > > The Thunderbolt units offered by Tom via TAPR to Time Nuts at that time > were old rejects that had done their duty already, were fully paid-off and > would have been scrapped and recycled by the Telecom otherwise, and Tom > invested a huge amount of his time testing them and packaging/shipping > them at > no charge, so that pricing was completely random and lucky for us to be at > the right time at the right moment. > > In fact the complete used Thunderbolt package now lists for up to $498 on > Ebay.. > > No problem on offering these kits factory-new with warranty at what we > hope is a fair price, > Bye, > Said > > > In a message dated 10/17/2014 12:49:32 Pacific Daylight Time, > p...@petelancashire.com writes: > > First three cheers to LTE for making these available. > > It reminds me when Motorola made a developers kit for the then > new 68HC11 MCU available for $68.11. > > I know of one design win they got that more then made of their marketing > costs. > > Another that hit me is with inflation the LTE Lite is not much more then > what many of us paid for our Thunderbolts. > > For those new to the list ... > > https://www.febo.com/pipermail/time-nuts/2008-May/031100.html > > http://www.leapsecond.com/pages/tapr-tbolt/ > > In 2008, $124, the LTE Lite in 2014 $195. > > With 'real' inflation (not the 11% you get online) the $71 difference is > not much more. > > My two backup Thunderbolts cost me $145 each, just before they hit $200 > then became history. > > Again thanks to Said and JLT > > -pete > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
How much would we guess that Wenzel blue-top would run you? Relative to the low cost GPSDO, my understanding is the Wenzel parts are priced appropriately to their quality. On Fri, Oct 17, 2014 at 11:32 AM, S. Jackson via time-nuts < time-nuts@febo.com> wrote: > > Hello Jim, > let me answer through Time Nuts as this may interest other parties as > well. > Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V > CMOS output from the LTE-Lite module will preserve the phase noise > (actually > improve it by up to 6dB due to the 20log(n/m) noise improvement) and will > not add any spurs if you use the clean 3.0V output from the LTE-Lite > module > or an external clean power supply (please note the LTE-Lite TCXO RF output > is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the > TCXO and buffer). > Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on > our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and > using a fast CMOS divider will result in additive phase noise that will be > below the crystal oscillator phase noise floor. > That will result in significantly better phase noise and much lower spurs > than using the synthesized 10MHz output from the board, and one 74' chip > can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is > exactly what we would do here if we needed a clean 10MHz from the 20MHz > LTE-Lite board. > I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel > already packaged-up and connectorized as well. > Hope that helps, > Said > Hi Said > I was one of those looking for 10Mhz but I just thought again now that it > might be just as well to divide the standard 20Mhz output by 2 using a FF. > I think that would preserve all the desirable characteristics of the 20Mhz > signal which I understand to just be square wave at CMOS 3.3v levels > anyway. Is that correct? > Thanks > Jim > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
Hi there, I don't know how much the Wenzel units are, but if someone is not able to, or willing to build one on their own then this could be a viable alternative. I will look into writing a short appnote describing how a low-noise div-by-2 can be built at home with minimal components using a surface mount '74 chip and a couple of passives. Lastly the 20MHz LTE-Lite boards do generate a 10MHz output of course, and if you feed that into a standard counter (5370B, 53132A etc etc) I think the noise floor of the counter would be higher than the noise floor of the synthesized 10MHz output, so you would not see any difference between using the noisier synthesized output and the low-noise 10MHz TCXO divided output.. Bye, Said In a message dated 10/17/2014 13:19:08 Pacific Daylight Time, gign...@gmail.com writes: How much would we guess that Wenzel blue-top would run you? Relative to the low cost GPSDO, my understanding is the Wenzel parts are priced appropriately to their quality. On Fri, Oct 17, 2014 at 11:32 AM, S. Jackson via time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > wrote: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto:time-nuts@febo.com) To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LTE-Lite module
I have emailed Wenzel about pricing and whether or not they will sell small quantities. Will advise. Jim wb4...@amsat.org On 10/17/2014 2:32 PM, S. Jackson via time-nuts wrote: Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Hi NS, considering that they will be priced in quantity at 1/10th to 1/20th of what the Thunderbolt costs new I would say very well. In fact our module supports WAAS/EGNOS/MSAS and QZSS, and up to 65 GPS channels which the Thunderbolt does not support at all, so how do you compare that? Also how much warranty does your Thunderbolt have remaining on it? Thought so. bye, Said In a message dated 10/17/2014 13:20:40 Pacific Daylight Time, gign...@gmail.com writes: How do you feel your module compares to that old Thunderbolt, Said? NS On Fri, Oct 17, 2014 at 1:13 PM, S. Jackson via time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > wrote: Pete, that is not inflation, that is supply and demand. The Trimble Mini-T was priced at $945 on Trimble's standard price list for 1 to 9 pieces, and the Thunderbolt was likely twice that much when sold new, so you have to compare that to the LTE-Lite pricing. The Thunderbolt units offered by Tom via TAPR to Time Nuts at that time were old rejects that had done their duty already, were fully paid-off and would have been scrapped and recycled by the Telecom otherwise, and Tom invested a huge amount of his time testing them and packaging/shipping them at no charge, so that pricing was completely random and lucky for us to be at the right time at the right moment. In fact the complete used Thunderbolt package now lists for up to $498 on Ebay.. No problem on offering these kits factory-new with warranty at what we hope is a fair price, Bye, Said In a message dated 10/17/2014 12:49:32 Pacific Daylight Time, _pete@petelancashire.com_ (mailto:p...@petelancashire.com) writes: First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto:time-nuts@febo.com) To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
And, somehow I expect that my LTE-LITE will actually work, which my thunderbolt never did. (Very noisy) It continues to collect dust On 10/17/2014 3:49 PM, Pete Lancashire wrote: First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
Pete, that is not inflation, that is supply and demand. The Trimble Mini-T was priced at $945 on Trimble's standard price list for 1 to 9 pieces, and the Thunderbolt was likely twice that much when sold new, so you have to compare that to the LTE-Lite pricing. The Thunderbolt units offered by Tom via TAPR to Time Nuts at that time were old rejects that had done their duty already, were fully paid-off and would have been scrapped and recycled by the Telecom otherwise, and Tom invested a huge amount of his time testing them and packaging/shipping them at no charge, so that pricing was completely random and lucky for us to be at the right time at the right moment. In fact the complete used Thunderbolt package now lists for up to $498 on Ebay.. No problem on offering these kits factory-new with warranty at what we hope is a fair price, Bye, Said In a message dated 10/17/2014 12:49:32 Pacific Daylight Time, p...@petelancashire.com writes: First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Price of LTE Lite GPSDO vs Trimble Thunderbolt.
First three cheers to LTE for making these available. It reminds me when Motorola made a developers kit for the then new 68HC11 MCU available for $68.11. I know of one design win they got that more then made of their marketing costs. Another that hit me is with inflation the LTE Lite is not much more then what many of us paid for our Thunderbolts. For those new to the list ... https://www.febo.com/pipermail/time-nuts/2008-May/031100.html http://www.leapsecond.com/pages/tapr-tbolt/ In 2008, $124, the LTE Lite in 2014 $195. With 'real' inflation (not the 11% you get online) the $71 difference is not much more. My two backup Thunderbolts cost me $145 each, just before they hit $200 then became history. Again thanks to Said and JLT -pete ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] LTE-Lite module
Hello Jim, let me answer through Time Nuts as this may interest other parties as well. Yes, using a fast flip flop to generate 10MHz out of the 20MHz TCXO 3.0V CMOS output from the LTE-Lite module will preserve the phase noise (actually improve it by up to 6dB due to the 20log(n/m) noise improvement) and will not add any spurs if you use the clean 3.0V output from the LTE-Lite module or an external clean power supply (please note the LTE-Lite TCXO RF output is 3.0V due to the internal 3.3V to 3.0V Low Noise regulator feeding the TCXO and buffer). Use fast logic such as 74AC74, 74FCT74, or the like. We do exactly that on our ULN-2550 boards to generate 50MHz and 25MHz out of the 100MHz, and using a fast CMOS divider will result in additive phase noise that will be below the crystal oscillator phase noise floor. That will result in significantly better phase noise and much lower spurs than using the synthesized 10MHz output from the board, and one 74' chip can generate both 10MHz and 5MHz out of the 20MHz LTE-Lite output. This is exactly what we would do here if we needed a clean 10MHz from the 20MHz LTE-Lite board. I believe you can order low-noise divide-by-2 blue-top boxes from Wenzel already packaged-up and connectorized as well. Hope that helps, Said Hi Said I was one of those looking for 10Mhz but I just thought again now that it might be just as well to divide the standard 20Mhz output by 2 using a FF. I think that would preserve all the desirable characteristics of the 20Mhz signal which I understand to just be square wave at CMOS 3.3v levels anyway. Is that correct? Thanks Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
All: Some very good information here. I use NFPA codes in my day job. JUST YESTERDAY, I learned that you can read their standards for free. Go to their site, and you'll see a link for free access to any of their standards. You can't save or print, but you can read. You will have to create an account, but they don't demand anything that isn't already public. 73, Jim wb4...@amsat.org On 10/17/2014 12:11 PM, Jim Lux wrote: On 10/17/14, 8:17 AM, Chris Albertson wrote: You can use metal conduit as the bonding conductor between grounding systems, for one thing. That works fine, but I think it is disallowed by the electrical code. If you used metallic conduit it MUST be grounded but you can't use it for grounding. That said, it does work. I think the danger the electric code addresses is that connections between conduit sections become loose over time and might corrode. The metallic raceway (code speak for conduit) is allowed to be the bonding conductor (bonding conductor = "greenwire" or "electrical safety" ground in code speak). Properly installed conduit will have a good connection, etc.. When interconnecting multiple grounding electrodes or electrode systems is where the requirements for particular gauges of wire come in, and mostly it has to do with mechanical strength and reliability. You can use a smaller conductor if it is protected inside something, for instance. The other rule is that the bonding conductor has to be continuous (the concern you mentioned about connections becoming loose, etc). http://lightning.org/wp-content/uploads/2013/04/Bonding-2013-ULPA-LPI-rev1.pdf is a very nice summary Mike Holt (http://www.mikeholt.com/) has a great website on all code related issues, and he's written a bunch of articles that explain the code and the rationale behind the requirements. http://ecmweb.com/code-basics/grounding-and-bonding-part-1-3 And when it comes to antennas and the like, you're in a different section of the code 810, 820, and the requirements for the grounding conductor (and whether coax shield can be that grounding conductor) are all laid out there. In many case, the coax shield can serve as the grounding conductor, but only if there are no connectors in the path (i.e. you have to have a clamp that directly contacts the shield where it interconnects with the building grounding system). A barrel feedthrough in a grounded metal panel doesn't meet the strict requirements of the code (although personally, I think it's a fine solution) One thing to remember about the NEC requirements is that the "threat" they are protecting against with the grounding and bonding requirements is NOT a lightning strike. It's contact with an energized conductor (e.g. a power line touches your antenna or supporting structure). That's a whole lot more common (wind storms, etc.) NFPA 780 is the lightning protection code, and has a lot more "lightning protection" aspects. The NEC cares almost nothing about transient protection, the concern is more about electrical shocks and burning the building down. Furthermore, the NEC really only regulates the wiring in your building, and nothing that is connected to it, nor does it regulate the wiring of the power company. There are two tomes of reference I use for transient protection: one is IEEE 1100 (the Emerald Book) which has gone under many names over the years (politics.. computer manufacturers did not want their equipment described as "sensitive electronic equipment") http://standards.ieee.org/findstds/standard/1100-2005.html The other is "Protection of Electronic Circuits from Overvoltages" by R.B. Standler. http://www.amazon.com/gp/search?index=books&linkCode=qs&keywords=9780486425528 http://store.doverpublications.com/0486425525.html And, if you're at the Dover Pubs store.. take a look at the books about lightning from Martin Uman. Very readable, lots of technical info. I think the threaded conduit would work fine. That stuff is like water pipe but smoother inside. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
Hello All - There is a 500+ page document on grounding, lightning protection and more - Google for: STANDARDS AND GUIDELINES FOR COMMUNICATION SITES Motorola R56 2005 Regards, John K1AE ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
On 10/17/14, 8:17 AM, Chris Albertson wrote: You can use metal conduit as the bonding conductor between grounding systems, for one thing. That works fine, but I think it is disallowed by the electrical code. If you used metallic conduit it MUST be grounded but you can't use it for grounding. That said, it does work. I think the danger the electric code addresses is that connections between conduit sections become loose over time and might corrode. The metallic raceway (code speak for conduit) is allowed to be the bonding conductor (bonding conductor = "greenwire" or "electrical safety" ground in code speak). Properly installed conduit will have a good connection, etc.. When interconnecting multiple grounding electrodes or electrode systems is where the requirements for particular gauges of wire come in, and mostly it has to do with mechanical strength and reliability. You can use a smaller conductor if it is protected inside something, for instance. The other rule is that the bonding conductor has to be continuous (the concern you mentioned about connections becoming loose, etc). http://lightning.org/wp-content/uploads/2013/04/Bonding-2013-ULPA-LPI-rev1.pdf is a very nice summary Mike Holt (http://www.mikeholt.com/) has a great website on all code related issues, and he's written a bunch of articles that explain the code and the rationale behind the requirements. http://ecmweb.com/code-basics/grounding-and-bonding-part-1-3 And when it comes to antennas and the like, you're in a different section of the code 810, 820, and the requirements for the grounding conductor (and whether coax shield can be that grounding conductor) are all laid out there. In many case, the coax shield can serve as the grounding conductor, but only if there are no connectors in the path (i.e. you have to have a clamp that directly contacts the shield where it interconnects with the building grounding system). A barrel feedthrough in a grounded metal panel doesn't meet the strict requirements of the code (although personally, I think it's a fine solution) One thing to remember about the NEC requirements is that the "threat" they are protecting against with the grounding and bonding requirements is NOT a lightning strike. It's contact with an energized conductor (e.g. a power line touches your antenna or supporting structure). That's a whole lot more common (wind storms, etc.) NFPA 780 is the lightning protection code, and has a lot more "lightning protection" aspects. The NEC cares almost nothing about transient protection, the concern is more about electrical shocks and burning the building down. Furthermore, the NEC really only regulates the wiring in your building, and nothing that is connected to it, nor does it regulate the wiring of the power company. There are two tomes of reference I use for transient protection: one is IEEE 1100 (the Emerald Book) which has gone under many names over the years (politics.. computer manufacturers did not want their equipment described as "sensitive electronic equipment") http://standards.ieee.org/findstds/standard/1100-2005.html The other is "Protection of Electronic Circuits from Overvoltages" by R.B. Standler. http://www.amazon.com/gp/search?index=books&linkCode=qs&keywords=9780486425528 http://store.doverpublications.com/0486425525.html And, if you're at the Dover Pubs store.. take a look at the books about lightning from Martin Uman. Very readable, lots of technical info. I think the threaded conduit would work fine. That stuff is like water pipe but smoother inside. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
Dave, We have a 26 dB Lucent (TMG-HR-26NCM) antenna mounted on the gable end of the N2MO station. The feed line (1/2 superflex) runs straight down to a watertight steel box with a Polyphaser GPS protector. The superflex shield is tied to the ground with the standard Andrew kit. Both the antenna mounting pipe and protector have a #2 grounding wire to an 8' rod. When the ring ground is replaced we will weld it to existing rod from two directions. I can prove links to pictures if it helps. Martin Flynn . 26dB On Thu, Oct 16, 2014 at 4:34 PM, Dave M wrote: I'm looking for effective coaxial lightning arrestors for my GPSDO antennas. I've seen several types; those completely enclosed in a one-piece metal enclosure (no replaceable components) and those having a replaceable gas discharge tube seem to predominate the list. I'm looking closely at the gas discharge tube types, and am curious as to their effectiveness and durability. I'd like to know stuff like; are they effective in dissipating a static charge, how do I know when the gas tube needs to be replaced, are the gas tubes of a special type, are replacement gas tube easily available, etc. I'm interested in opinions and experiences with arrestors and recommendations for which type is most effective. Thanks for comments, Dave M _ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
> You can use metal conduit as the bonding conductor between grounding > systems, for one thing. That works fine, but I think it is disallowed by the electrical code. If you used metallic conduit it MUST be grounded but you can't use it for grounding. That said, it does work. I think the danger the electric code addresses is that connections between conduit sections become loose over time and might corrode. I think the threaded conduit would work fine. That stuff is like water pipe but smoother inside. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS Lightning Protection
Dave M, The advice about a 'system approach' is essential, or the lightning discharge may go through your building wiring instead of through your ground rod. Or, a lightning strike down the street may follow the power line, pass through your home wiring, GPS receiver, and into your GPS antenna ground. A nice overview of the basics of such a system approach for residential locations is presented in the IEEE Guide to Surge protection. www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf Since some time-nutters may be experimenting in residential settings, this guide may be more useful than guidance for industrial settings. There are now approved ground bonding assemblies available for about $10 US dollars. (They're called 'Intersystem Bonding Termination' devices.). This can simplify the creation of a single ground point, and can help eliminate the clutter telephone and CATV grounding attachments to the electrical service ground. Get a licensed electrician to install it; don't modify your electrical service ground on your own. Also, you mentioned something about connecting a copper wire to Aluminum. That may present problems or even be illegal in your area unless it is done correctly. In the U.S. you should check a recent edition of NFPA 780 and your local electrical code. Also, if your home has lightning rods, these need to be included in the design. Regarding gas discharge tubes, these are widely used, and they are often designed to fail 'shorted', so you can tell if they've failed by loss of signal. Replacement gas discharge tubes are available from the manufacturers. The gas discharge units for GPS systems are designed to let the DC control voltage pass through ( usually 5 volts, some systems use 12 (eg some Symmetricom receivers)) and clamp any voltage higher that this. Note that the voltage referred to here is the difference between the shield and center conductor of the coax. You should look for an arrestor that handles the GPS frequency, and passes the DC voltage (non DC blocking) but limits surges to 6 or 15 volts (depending on your GPS supply voltage) , but not 300 or 600 volts that is common for suppressors designed for service with low power transmitters. Some systems use two lightning arrestors, one at the antenna to protect it fromsurges appearing on the feedline, and one at the point of entry/single ground point. Once you have a look at the IEEE guide, and the NFPA guide, you'll shudder when you read internet postings like : 'I just connected a lightning supressor to my radio and ran a wire to a 4 foot ground rod outside my window. It seems to be working fine'. Best of Luck! Ed > > On Oct 16, 2014, at 7:34 PM, Dave M wrote: > > > > I'm looking for effective coaxial lightning arrestors for my GPSDO antennas. > > I've seen several types; those completely enclosed in a one-piece metal > > enclosure (no replaceable components) and those having a replaceable gas > > discharge tube seem to predominate the list. > > I'm looking closely at the gas discharge tube types, and am curious as to > > their effectiveness and durability. I'd like to know stuff like; are they > > effective in dissipating a static charge, how do I know when the gas tube > > needs to be replaced, are the gas tubes of a special type, are replacement > > gas tube easily available, etc. > > > > I'm interested in opinions and experiences with arrestors and > > recommendations for which type is most effective. > > > > Thanks for comments, > > Dave M > > ___ > > time-nuts mailing list -- time-nuts@febo.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
On 10/17/14, 6:26 AM, Chris Albertson wrote: On Thu, Oct 16, 2014 at 7:51 PM, Dave M wrote: Thanks, Chris. I've done a bit or research on the subject, and think I have a reasonable grip on the necessary steps. I have an 8' ground rod driven into the ground directly under the spot where my antennas mount. #6 solid copper from the rod to a heavy aluminum plate, where the arrestors will be mounted. A #6 solid copper wire from the plate to the antenna mounting structure. About the only thing you left out is the interconnection between this new ground rod and the existing house ground. Sounds like you must live in Florida. The best source of information is the lightening lab at University of FL. I've never read a good research backed paper on plastic v. metal conduit. You can use metal conduit as the bonding conductor between grounding systems, for one thing. I bet it does matter. I use iron pipe outdoors then after it gets indoors switch to plastic. Practical reasons. The flexible plastic conduit is just easier to use ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
On Thu, Oct 16, 2014 at 7:51 PM, Dave M wrote: > Thanks, Chris. > I've done a bit or research on the subject, and think I have a reasonable > grip on the necessary steps. I have an 8' ground rod driven into the > ground directly under the spot where my antennas mount. #6 solid copper > from the rod to a heavy aluminum plate, where the arrestors will be > mounted. A #6 solid copper wire from the plate to the antenna mounting > structure. About the only thing you left out is the interconnection between this new ground rod and the existing house ground. Sounds like you must live in Florida. The best source of information is the lightening lab at University of FL. I've never read a good research backed paper on plastic v. metal conduit. I bet it does matter. I use iron pipe outdoors then after it gets indoors switch to plastic. Practical reasons. The flexible plastic conduit is just easier to use -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
A peak inside a PolyPhaser 095-0927T-A unit http://users.burlingtontelecom.net/~n1...@burlingtontelecom.net/images/gps_surge.jpg Mike On 10/17/2014 2:18 AM, John C. Westmoreland, P.E. wrote: Hello Dave, I think we had a similar question recently - and I have been told the PolyPhaser products are gas tubes - I haven't opened one up yet. TESSCO sells these online - you can find them here: https://www.tessco.com/products/displayProducts.do?groupId=90143&subgroupId=91046 Regards, John W. On Thu, Oct 16, 2014 at 10:23 PM, ed breya wrote: Of all device types, I think gas tubes are the best for this sort of application - very low C, and high surge current rating. I'm picturing the kind that are used in power supplies and such for limiting line transients - about 1 cm dia and length with axial leads. I don't know what kind are used in "lightning arrestors," if they are the same or scaled up in size. Whether you make it able to take a direct hit depends on how big of a hit, your budget, and the environment of the antenna and lines. If it's the tallest thing in a huge field in a lightning-prone area, then it could be a big issue, but I don't think most people have that situation. You may want to look at the US National Electrical Code (NEC) for ideas - I believe that subject is covered there. The main thing there would be safety against injuries and fire, even if the equipment is destroyed. I think what you would want is kind of a pi network - the lowest impedance path to ground at the antenna zone that can be practically realized, then a high common-mode impedance (or even fusible) line to carry the signal to the building, then another low impedance path to ground at the building. This means that in my opinion, you should not put the feedline in metal conduit unless it's essential for protection - or underground, which should improve the grounding. You want the antenna zone to absorb the brunt of any discharge, then use the higher line Zcm to hopefully give some degree of isolation from there to the building. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/ mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- 73, Mike, N1JEZ "A closed mouth gathers no feet" ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
Hello Dave, I think we had a similar question recently - and I have been told the PolyPhaser products are gas tubes - I haven't opened one up yet. TESSCO sells these online - you can find them here: https://www.tessco.com/products/displayProducts.do?groupId=90143&subgroupId=91046 Regards, John W. On Thu, Oct 16, 2014 at 10:23 PM, ed breya wrote: > Of all device types, I think gas tubes are the best for this sort of > application - very low C, and high surge current rating. I'm picturing the > kind that are used in power supplies and such for limiting line transients > - about 1 cm dia and length with axial leads. I don't know what kind are > used in "lightning arrestors," if they are the same or scaled up in size. > > Whether you make it able to take a direct hit depends on how big of a hit, > your budget, and the environment of the antenna and lines. If it's the > tallest thing in a huge field in a lightning-prone area, then it could be a > big issue, but I don't think most people have that situation. > > You may want to look at the US National Electrical Code (NEC) for ideas - > I believe that subject is covered there. The main thing there would be > safety against injuries and fire, even if the equipment is destroyed. > > I think what you would want is kind of a pi network - the lowest impedance > path to ground at the antenna zone that can be practically realized, then a > high common-mode impedance (or even fusible) line to carry the signal to > the building, then another low impedance path to ground at the building. > This means that in my opinion, you should not put the feedline in metal > conduit unless it's essential for protection - or underground, which should > improve the grounding. You want the antenna zone to absorb the brunt of any > discharge, then use the higher line Zcm to hopefully give some degree of > isolation from there to the building. > > Ed > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Inmarsat needs a time-nut
Hi One would *hope* that they can do the same process with an aircraft on a known route and get data that makes sense. If that “fact check” is missing from the report … not good. Bob > On Oct 17, 2014, at 5:22 AM, Poul-Henning Kamp wrote: > > Inmarsats long awaited article about the MH370 calculations is now > available: > > > journals.cambridge.org/download.php?file=%2FNAV%2FS037346331400068Xa.pdf&code=99d6daf127f9c88ca22b52fd9ff5084a > > I think I've spotted a weakness. > > The "BFO-Bias" is the frequency error of the aircraft terminals > timebase and the calibrate it to 150Hz using communications while > the plane is on the ground. > > The terminal most likely uses a TCXO for the rapid startup. > > A 150Hz error on a 10MHz TCXO would be 15PPM which would be > impressively bad for this kind of application. > > Its therefore likely that the TCXO is in the 100MHz range giving > an error of a more likely 1.5PPM. > > The aircraft terminal is powered down and possibly in very hostile > environmentals for around one hour, prior to the log-on at 18:25:27Z, > but Inmarsat assume, without any comment or qualification, that the > BFO-bias is still the same and still constant. > > I don't think those are valid assumptions. > > Retrace is typically not specified for TCXOs, for a good reason. > > I don't think it is unreasonable to assume that the TCXO came up > with a difference of +/- 1PPM from the previous frequency, after > being turned off for an hour, where both temperature and air pressure > may have violated specs. > > That means that the BFO-bias after the 18:25:27Z logon isn't 150Hz, > but somewhere in [50...250Hz], and what's more, it's probably not > even constant for the first 10-15 minutes after power-on. > > (In fact, I'm not even sure that the assumption that the frequency > offset at ground level can be used at lower air-pressure at > flight-level in the first place.) > > I havn't gone through their math to see what the implications would > be, but I think it will vastly ruin the geometry of the fix. > > > Poul-Henning > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Lightning arrestors for GPSDO antenna
If anyone is interested, I have a few NOS Zap-Tech 30-105 (now called CX-TF apparently) surge suppressors available. These are basically a single shunt gas tube (the coaxial center conductor runs through the center of a custom gas tube), and they were sold as GPS in-line suppressors. I use them at the far end of the rf spectrum: all of my receive-only wire antennas (Beverages) for 1.8-7 MHz have one on each feedline where they enter the house. These antennas are up to 800' long, and I know for a fact they pick up surges from every passing storm and, so far, the elephants have stayed away... ;-) These units have TNC female adapters on both ends, but if the TNCs are screwed off (they are loc-tite'd on), there are F-female connectors underneath. $20 will get one mailed in the US. 73, geo - n4ua On Fri, Oct 17, 2014 at 1:23 AM, ed breya wrote: > Of all device types, I think gas tubes are the best for this sort of > application - very low C, and high surge current rating. I'm picturing the > kind that are used in power supplies and such for limiting line transients > - about 1 cm dia and length with axial leads. I don't know what kind are > used in "lightning arrestors," if they are the same or scaled up in size. > > Whether you make it able to take a direct hit depends on how big of a hit, > your budget, and the environment of the antenna and lines. If it's the > tallest thing in a huge field in a lightning-prone area, then it could be a > big issue, but I don't think most people have that situation. > > You may want to look at the US National Electrical Code (NEC) for ideas - > I believe that subject is covered there. The main thing there would be > safety against injuries and fire, even if the equipment is destroyed. > > I think what you would want is kind of a pi network - the lowest impedance > path to ground at the antenna zone that can be practically realized, then a > high common-mode impedance (or even fusible) line to carry the signal to > the building, then another low impedance path to ground at the building. > This means that in my opinion, you should not put the feedline in metal > conduit unless it's essential for protection - or underground, which should > improve the grounding. You want the antenna zone to absorb the brunt of any > discharge, then use the higher line Zcm to hopefully give some degree of > isolation from there to the building. > > Ed > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Inmarsat needs a time-nut
Inmarsats long awaited article about the MH370 calculations is now available: journals.cambridge.org/download.php?file=%2FNAV%2FS037346331400068Xa.pdf&code=99d6daf127f9c88ca22b52fd9ff5084a I think I've spotted a weakness. The "BFO-Bias" is the frequency error of the aircraft terminals timebase and the calibrate it to 150Hz using communications while the plane is on the ground. The terminal most likely uses a TCXO for the rapid startup. A 150Hz error on a 10MHz TCXO would be 15PPM which would be impressively bad for this kind of application. Its therefore likely that the TCXO is in the 100MHz range giving an error of a more likely 1.5PPM. The aircraft terminal is powered down and possibly in very hostile environmentals for around one hour, prior to the log-on at 18:25:27Z, but Inmarsat assume, without any comment or qualification, that the BFO-bias is still the same and still constant. I don't think those are valid assumptions. Retrace is typically not specified for TCXOs, for a good reason. I don't think it is unreasonable to assume that the TCXO came up with a difference of +/- 1PPM from the previous frequency, after being turned off for an hour, where both temperature and air pressure may have violated specs. That means that the BFO-bias after the 18:25:27Z logon isn't 150Hz, but somewhere in [50...250Hz], and what's more, it's probably not even constant for the first 10-15 minutes after power-on. (In fact, I'm not even sure that the assumption that the frequency offset at ground level can be used at lower air-pressure at flight-level in the first place.) I havn't gone through their math to see what the implications would be, but I think it will vastly ruin the geometry of the fix. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hello, You could find off the shelves units from www.gpssource.com MS22 or MS24. For standard splitter www.instockwireless.com with the GPS200/201 and GPS400/401 are interesting. Regards Luc -Message d'origine- De : time-nuts [mailto:time-nuts-boun...@febo.com] De la part de Dave M Envoyé : jeudi 16 octobre 2014 01:44 À : Discussion of precise time and frequency measurement Objet : Re: [time-nuts] WTB: GPS Antenna Splitter Pete, I see a ZAPD-30 on the miniCircuits web site. Might those be the models that you have? If so, (and assuming that you can find them), how much for a couple? Thanks, Dave M Peter Loron wrote: > Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking > around. I'll try to get a look in the stash this weekend. > > -Pete > > On 2014-10-06 13:01, Dave M wrote: >> Does anyone in the group have, or can point me to, a low-cost (but >> not cheap) 2-port splitter for a GPS antenna? Those on Ebay are >> rather expensive. >> >> I have two GPSDO units, and have both an older timing antenna and a >> new choke ring antenna (Thanks, Pete L). I already have one 2-port >> splitter (working well), but my intent is to connect both antennas >> through the splitters and a couple coaxial relays so that I can, with >> the twist of a switch, allow me to run each GPS from a different >> antenna, or both from the same antenna. I would like to gather some >> data as to the differences between the two antennas. I know I could >> switch the connections manually, but I like the idea of a switch to >> sort of automate the connections, and I'd need another splitter >> anyway. >> >> Before I go to the trouble and expense of building upon this idea, >> are there any comments as to the value of the project? >> Some questions come to mind: >> I'm thinking about mounting both antennas on the same mast, at the >> same elevation, just separated by a couple feet. Any problems that I >> should be aware of by putting both antennas so close together? Will >> that small distance have a noticeable effect when switching a >> receiver from one antenna to the other? Will the GPS notice the >> difference and want to do another survey? >> >> Thanks for your comments. >> Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
