Re: [time-nuts] ANN: UK MSF 60 kHz interruption, 2012 June 14
Le 4 juin 2012 à 05:43, David I. Emery a écrit : On Sun, Jun 03, 2012 at 09:20:59AM -0700, J. Forster wrote: Is there any indication the carriers of WWVB and MSF are locked together? -John = Given it's only 60 KHz and certainly somewhere north of parts in 10^13 and probably down to 10^14 or 10^15 the distinction kinda escapes one. They may not be locked to each other, but are so close in frequency that relative drift would be AWFULLY slow... especially if its more like 10^15 from primary maser standards... There are only 5.184 * 10^9 cycles of 60 KHz in a day after all... and it takes a while for a error of a few parts in 10^15 to pile up to one whole cycle... From the doc on NIST and NPL sites, we are not in maser country here. The transmitters frequencies are disciplined by cesium standards. For WWVB the frequency is kept to a few parts in 10^13 ( NIST Special Publication 423) and for MSF at 2 parts in 10^12 and are both sync'd to UTC(k). As tvb points out, the the received signal will be phase shifted according to TOD and atmospheric conditions. The guys at NPL monitor(ed) the MSF signal to provide(ed) data for anyone wanting to use it for calibration in monthly bulletins of performance. I expect NIST do the same for WWVB but have been able to find a ref. Check out http://npl.co.uk/upload/pdf/user_guide_bullitins.pdf and the last bulletin that the site links point to , for april 2011, http://resource.npl.co.uk/time/bulletins/msf/msfbul_04_2011.pdf. What is interesting from the MSF data is that the phase offsets are quite significant where they are received in what I expect are optimal conditions at midday when ionospheric effects are minimal. I don't know what happened to latter issues if any. Did they abandon them? ___ 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] ANN: UK MSF 60 kHz interruption, 2012 June 14
As noted above the propagation can make quite a mess of things. When wwvb launched way back there was a HP journal showing that in NY city you could establish something like 1 X 10-7th as I recall. I have seen all the propagation twists and turns. I suppose if you were 300-400 miles from the transmitter and could receive groundwave signals you might do 10 X better or more. Regards Paul. On Mon, Jun 4, 2012 at 3:35 AM, mike cook michael.c...@sfr.fr wrote: Le 4 juin 2012 à 05:43, David I. Emery a écrit : On Sun, Jun 03, 2012 at 09:20:59AM -0700, J. Forster wrote: Is there any indication the carriers of WWVB and MSF are locked together? -John = Given it's only 60 KHz and certainly somewhere north of parts in 10^13 and probably down to 10^14 or 10^15 the distinction kinda escapes one. They may not be locked to each other, but are so close in frequency that relative drift would be AWFULLY slow... especially if its more like 10^15 from primary maser standards... There are only 5.184 * 10^9 cycles of 60 KHz in a day after all... and it takes a while for a error of a few parts in 10^15 to pile up to one whole cycle... From the doc on NIST and NPL sites, we are not in maser country here. The transmitters frequencies are disciplined by cesium standards. For WWVB the frequency is kept to a few parts in 10^13 ( NIST Special Publication 423) and for MSF at 2 parts in 10^12 and are both sync'd to UTC(k). As tvb points out, the the received signal will be phase shifted according to TOD and atmospheric conditions. The guys at NPL monitor(ed) the MSF signal to provide(ed) data for anyone wanting to use it for calibration in monthly bulletins of performance. I expect NIST do the same for WWVB but have been able to find a ref. Check out http://npl.co.uk/upload/pdf/user_guide_bullitins.pdf and the last bulletin that the site links point to , for april 2011, http://resource.npl.co.uk/time/bulletins/msf/msfbul_04_2011.pdf. What is interesting from the MSF data is that the phase offsets are quite significant where they are received in what I expect are optimal conditions at midday when ionospheric effects are minimal. I don't know what happened to latter issues if any. Did they abandon them? ___ 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] GPS and Rubidium frequency standards and noise question (newbie).
On Sun, 03 Jun 2012 18:16:15 -0400, Bob Camp wrote: Hi As long as it shows rev E or rev D it's likely a later version unit. The date code on the OCXO is the best indicator, but even that's not 100%. As long as it's one made after about 2002 you will have a good one. Search on Eb..: 10mhz gps I bought 2 from the American seller , he has Item# 170848624524 And they were Rev E , after a month or so i bought some of the old DS1620 temp sensor chips Item # 110888667598 , but i think these might be the old type also Item # 140376728803 , in the US. The old DS1620's are purely cosmetic (I have been told) , but i like the moving temperature graphs. Then you'd need: A PSU (+/-12v +5v - Ie. Item# 170609590979) A gps timing antenna (26+ dB or so - Ie. Item# 180518378555) - This type have an N-Connector mounted , the Tbolt uses F-Connector , so get an N-to- F adapter , and some F-connector plugs. Last some good 4-shielded 75ohm sat cable. /Bingo ___ 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] WTB: Busted Tek TM500 Counters
Hi, If anybody has any busted Tek counters sitting somewhere, I'm looking for the following: DC503- NOT a DC503A- with a good aluminum front panel. All else can be trash. DC509- With all good LED displays (3x DL883A). All else can be NG. If you've got either described above, please email off-list. NOTE: Substituting different LEDs in the DC509 seems to be a hopeless proposition. Nothing I've seen fits. Thanks, -John == ___ 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: Busted Tek TM500 Counters
Hi, I have (4) DC503 for parts, all have good aluminum front panels one has a good plastic frame around the front panel. I am not sure about the operating condition but would check for you this evening. Make me an offer. Shipping would be from zip code 17404 PA Jeff -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: Monday, June 04, 2012 2:24 PM To: tekscop...@yahoogroups.com; testequiptra...@yahoogroups.com; time-nuts@febo.com Cc: hp_agilent_equipm...@yahoogroups.com Subject: [time-nuts] WTB: Busted Tek TM500 Counters Hi, If anybody has any busted Tek counters sitting somewhere, I'm looking for the following: DC503- NOT a DC503A- with a good aluminum front panel. All else can be trash. DC509- With all good LED displays (3x DL883A). All else can be NG. If you've got either described above, please email off-list. NOTE: Substituting different LEDs in the DC509 seems to be a hopeless proposition. Nothing I've seen fits. Thanks, -John == ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nut can answer
This is not exactly a time related question, but I'm sure the subject must be of interest to time-nuts using GPS. If one transmits from an antenna such as a helical one, RHCP, can the same antenna be used for reception, or does the helix need to be wound the other way? If you google this topic, there seems to be a lot of confusion about whether the TX antenna and RX antenna need to both have RHCP or whether one needs to be LHCP and the other RHCP. Given GPS uses circular polarization, I'm hoping someone here will know. It would appear there are different definitions of circular polarization, with one considering it from the point of view of the source, and the other considering it from the point of view of the receiver. The IEEE apparently uses the former, and others (especially optics) use the opposite. http://en.wikipedia.org/wiki/Circular_polarization My aim was to make a gain measurement of two circular polarized antennas. I have two identical antennas, but are unsure if the signals should be received strongly, or whether theoretically no signal would be received. (Of course in practice, one never achieves perfect polarization, so there will always be a signal detected, even if cross-polarized. ___ 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] LightSquared in the news again
From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nut can answer
On 05/06/12 00:30, Dr. David Kirkby wrote: This is not exactly a time related question, but I'm sure the subject must be of interest to time-nuts using GPS. If one transmits from an antenna such as a helical one, RHCP, can the same antenna be used for reception, or does the helix need to be wound the other way? If you google this topic, there seems to be a lot of confusion about whether the TX antenna and RX antenna need to both have RHCP or whether one needs to be LHCP and the other RHCP. Given GPS uses circular polarization, I'm hoping someone here will know. It would appear there are different definitions of circular polarization, with one considering it from the point of view of the source, and the other considering it from the point of view of the receiver. The IEEE apparently uses the former, and others (especially optics) use the opposite. http://en.wikipedia.org/wiki/Circular_polarization My aim was to make a gain measurement of two circular polarized antennas. I have two identical antennas, but are unsure if the signals should be received strongly, or whether theoretically no signal would be received. (Of course in practice, one never achieves perfect polarization, so there will always be a signal detected, even if cross-polarized. They would have to have opposite rotation. The waveform rotation will follow the transmitter antenna into the receiver antenna. The receiver antenna follows the same rotation that the transmitter antenna has, it's just that the face each other, so when you turn one of the 180 degrees such that they face the same direction you would see that they are in fact rotated in opposite directions. I'm sure the sat folks can confirm this. Cheers, Magnus ___ 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] LightSquared in the news again
Lightsquared is like a cockroach every time you think it is dead it shows up again. Thomas Knox 1-303-554-0307 Date: Mon, 4 Jun 2012 19:25:22 -0400 To: time-nuts@febo.com From: charles_steinm...@lavabit.com Subject: [time-nuts] LightSquared in the news again From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nut can answer
I don't think that's correct. A right-hand spiral (however you define right-hand) remains right-handed if you rotate the whole object in space so the centre axis of the spiral points in the opposite direction. A right-handed spiral is converted to a left-handed one only by reflecting it in a mirror. Try this: pick up two identical bolts. Think of the bolt heads as the feed end of the antenna, with the threads being the helical element. Rotate the two bolts so they are aligned on the same axis, but facing each other. Note that the threaded portions of both bolts spiral the same way. So two identical antennas will work fine as a transmit/receive pair over an open-space path. But if you bounce a RHCP signal off some passive reflector, the signal becomes LHCP (or vise versa), and the transmit and receive antennas need to be mirror images of each other. Dave On Mon, Jun 4, 2012 at 7:26 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 05/06/12 00:30, Dr. David Kirkby wrote: This is not exactly a time related question, but I'm sure the subject must be of interest to time-nuts using GPS. If one transmits from an antenna such as a helical one, RHCP, can the same antenna be used for reception, or does the helix need to be wound the other way? If you google this topic, there seems to be a lot of confusion about whether the TX antenna and RX antenna need to both have RHCP or whether one needs to be LHCP and the other RHCP. Given GPS uses circular polarization, I'm hoping someone here will know. It would appear there are different definitions of circular polarization, with one considering it from the point of view of the source, and the other considering it from the point of view of the receiver. The IEEE apparently uses the former, and others (especially optics) use the opposite. http://en.wikipedia.org/wiki/**Circular_polarizationhttp://en.wikipedia.org/wiki/Circular_polarization My aim was to make a gain measurement of two circular polarized antennas. I have two identical antennas, but are unsure if the signals should be received strongly, or whether theoretically no signal would be received. (Of course in practice, one never achieves perfect polarization, so there will always be a signal detected, even if cross-polarized. They would have to have opposite rotation. The waveform rotation will follow the transmitter antenna into the receiver antenna. The receiver antenna follows the same rotation that the transmitter antenna has, it's just that the face each other, so when you turn one of the 180 degrees such that they face the same direction you would see that they are in fact rotated in opposite directions. I'm sure the sat folks can confirm this. Cheers, Magnus __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
David, One of these two photos is correct (odd isn't it)... http://www.ausairpower.net/Block-IIR-M-SV-1S.jpg http://www.ausairpower.net/Block-IIR-M-SV-2S.jpg Maybe these break the tie: http://www.spacemankind.com/images/ms/20090817-lockheed-gps-iir-lr.jpg https://share.sandia.gov/news/resources/releases/2008/images/GPS1.jpg http://www.lockheedmartin.com/content/dam/lockheed/data/space/photo/pressrelease/GPS_4A_pr.jpg http://www.insidegnss.com/auto/popupimage/GPSIIF_photo_lo.jpg http://www.freepatentsonline.com/6653987-0-large.jpg /tvb ___ 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] LightSquared in the news again
Typical of technology companies that have more lawyers on staff than engineers. On Mon, Jun 4, 2012 at 5:09 PM, Tom Knox act...@hotmail.com wrote: Lightsquared is like a cockroach every time you think it is dead it shows up again. Thomas Knox 1-303-554-0307 Date: Mon, 4 Jun 2012 19:25:22 -0400 To: time-nuts@febo.com From: charles_steinm...@lavabit.com Subject: [time-nuts] LightSquared in the news again From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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] LightSquared in the news again
Or like a Burmese python. They come back and strangle everything. Then eat them. On Mon, Jun 4, 2012 at 8:33 PM, Eric Williams wd6...@earthlink.net wrote: Typical of technology companies that have more lawyers on staff than engineers. On Mon, Jun 4, 2012 at 5:09 PM, Tom Knox act...@hotmail.com wrote: Lightsquared is like a cockroach every time you think it is dead it shows up again. Thomas Knox 1-303-554-0307 Date: Mon, 4 Jun 2012 19:25:22 -0400 To: time-nuts@febo.com From: charles_steinm...@lavabit.com Subject: [time-nuts] LightSquared in the news again From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
This is a subject I have some familiarity with. A helix antenna which is right hand for receive is also right hand for transmit. Think of it this way. If you have a bolt with a nut on it and you turn the nut to the right it will move along the bolt away from you. If you turn the bolt around so you are looking at the other end and turn the nut to the right it will move away from you. For your transmit antenna the waves are moving away from you and turning to the right. For the other guy's receive antenna the waves are turning to the right and moving away from you. It's the same if you think of yourself as the receive guy and the other guy as transmitting. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Dr. David Kirkby david.kir...@onetel.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Monday, June 04, 2012 5:30 PM Subject: [time-nuts] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer This is not exactly a time related question, but I'm sure the subject must be of interest to time-nuts using GPS. If one transmits from an antenna such as a helical one, RHCP, can the same antenna be used for reception, or does the helix need to be wound the other way? If you google this topic, there seems to be a lot of confusion about whether the TX antenna and RX antenna need to both have RHCP or whether one needs to be LHCP and the other RHCP. Given GPS uses circular polarization, I'm hoping someone here will know. It would appear there are different definitions of circular polarization, with one considering it from the point of view of the source, and the other considering it from the point of view of the receiver. The IEEE apparently uses the former, and others (especially optics) use the opposite. http://en.wikipedia.org/wiki/Circular_polarization My aim was to make a gain measurement of two circular polarized antennas. I have two identical antennas, but are unsure if the signals should be received strongly, or whether theoretically no signal would be received. (Of course in practice, one never achieves perfect polarization, so there will always be a signal detected, even if cross-polarized. ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nut can answer
Not quite. The definition of right-hand circular polarization, as standardized by the IRE... is as follows: For an observer looking in the direction of propagation, the rotation of the electric-field vector in a transverse plane is clockwise. - Jasik, Antenna Engineering Handbook, First Edition, p17-3 A right-hand circularly polarized antenna both transmits and receives RHCP. What is confusing people is a reflection of a RHCP wave is a LHCP wave. -Chuck Harris Magnus Danielson wrote: On 05/06/12 00:30, Dr. David Kirkby wrote: This is not exactly a time related question, but I'm sure the subject must be of interest to time-nuts using GPS. If one transmits from an antenna such as a helical one, RHCP, can the same antenna be used for reception, or does the helix need to be wound the other way? If you google this topic, there seems to be a lot of confusion about whether the TX antenna and RX antenna need to both have RHCP or whether one needs to be LHCP and the other RHCP. Given GPS uses circular polarization, I'm hoping someone here will know. It would appear there are different definitions of circular polarization, with one considering it from the point of view of the source, and the other considering it from the point of view of the receiver. The IEEE apparently uses the former, and others (especially optics) use the opposite. http://en.wikipedia.org/wiki/Circular_polarization My aim was to make a gain measurement of two circular polarized antennas. I have two identical antennas, but are unsure if the signals should be received strongly, or whether theoretically no signal would be received. (Of course in practice, one never achieves perfect polarization, so there will always be a signal detected, even if cross-polarized. They would have to have opposite rotation. The waveform rotation will follow the transmitter antenna into the receiver antenna. The receiver antenna follows the same rotation that the transmitter antenna has, it's just that the face each other, so when you turn one of the 180 degrees such that they face the same direction you would see that they are in fact rotated in opposite directions. I'm sure the sat folks can confirm this. Cheers, Magnus ___ 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] LightSquared in the news again
It's not a technology company if it has more lawyers than engineers. Mike On 6/4/2012 7:33 PM, Eric Williams wrote: Typical of technology companies that have more lawyers on staff than engineers. On Mon, Jun 4, 2012 at 5:09 PM, Tom Knoxact...@hotmail.com wrote: Lightsquared is like a cockroach every time you think it is dead it shows up again. Thomas Knox 1-303-554-0307 Date: Mon, 4 Jun 2012 19:25:22 -0400 To: time-nuts@febo.com From: charles_steinm...@lavabit.com Subject: [time-nuts] LightSquared in the news again From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
Well, they could be consistent. Most of those photos show only two sizes of helix-type antennas. The larger diameter (probably lower frequency) are quadrifilar helix designs, and they are uniformly left hand thread helixes. (I assume that everyone agrees on what a left-hand thread looks like, no matter how they label circular polarization). The more numerous smaller diameter antennas are multi-turn one-element helixes, and they always seem to be right hand thread in all of the photos. The smaller antennas are almost certainly for L1. The complication is the Block-IIR-M-SV-2S photo. But it has *three* sizes of antennas visible. The largest are left-hand-thread quadhelix as before, and thus likely close to the same physical dimensions as the large antennas in the other photos. The mid-size ones are multi-element multi-turn helixes that look a lot like the quadhelixes in design except that the ends are left open. And they are about 2/3 the diameter of the quadhelixes, much larger than the simple helix antennas in the previous group, so probably for a different frequency. Then there are the smallest antennas, which appear to be a single-element helix with many many turns - but these are about 1/3 the diameter of the large quadhelixes, and thus *these* are likely the L1 antennas. And, if I look closely, these small helixes do appear to be right-hand-thread wound. Dave On Mon, Jun 4, 2012 at 8:24 PM, Tom Van Baak t...@leapsecond.com wrote: David, One of these two photos is correct (odd isn't it)... http://www.ausairpower.net/Block-IIR-M-SV-1S.jpg http://www.ausairpower.net/Block-IIR-M-SV-2S.jpg Maybe these break the tie: http://www.spacemankind.com/images/ms/20090817-lockheed-gps-iir-lr.jpg https://share.sandia.gov/news/resources/releases/2008/images/GPS1.jpg http://www.lockheedmartin.com/content/dam/lockheed/data/space/photo/pressrelease/GPS_4A_pr.jpg http://www.insidegnss.com/auto/popupimage/GPSIIF_photo_lo.jpg http://www.freepatentsonline.com/6653987-0-large.jpg /tvb ___ 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] LightSquared in the news again
A law firm with a technology department? -Dave - Original Message - From: Michael Blazer mbla...@satx.rr.com To: time-nuts@febo.com Sent: Monday, June 4, 2012 7:44:26 PM Subject: Re: [time-nuts] LightSquared in the news again It's not a technology company if it has more lawyers than engineers. Mike On 6/4/2012 7:33 PM, Eric Williams wrote: Typical of technology companies that have more lawyers on staff than engineers. On Mon, Jun 4, 2012 at 5:09 PM, Tom Knoxact...@hotmail.com wrote: Lightsquared is like a cockroach every time you think it is dead it shows up again. Thomas Knox 1-303-554-0307 Date: Mon, 4 Jun 2012 19:25:22 -0400 To: time-nuts@febo.com From: charles_steinm...@lavabit.com Subject: [time-nuts] LightSquared in the news again From today's communications news (fair use): LightSquared stressed its intention to deploy a nationwide 4G wireless broadband network, during a meeting with Angela Giancarlo, chief of staff to FCC Commissioner Robert McDowell. The commission has some legal and policy responses it can take to address the inability of a limited number of GPS receivers to operate properly in spectrum that has not been allocated for GPS use, the company said in an ex parte filing. It said the actions proposed in the commission's Feb. 15 public notice revoking its ancillary terrestrial component are disproportionate and inappropriate, especially in light of the current administrative record. http://apps.fcc.gov/ecfs/document/view;jsessionid=PbLJPNCL1F1v170xHrQhXLJlClpRjS2DfgWX7c4CqvvhwQlgG2nn!-1221852939!NONE?id=7021921317 ___ 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. ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
On 05/06/12 04:51, Dave Martindale wrote: Well, they could be consistent. Most of those photos show only two sizes of helix-type antennas. The larger diameter (probably lower frequency) are quadrifilar helix designs, and they are uniformly left hand thread helixes. (I assume that everyone agrees on what a left-hand thread looks like, no matter how they label circular polarization). The more numerous smaller diameter antennas are multi-turn one-element helixes, and they always seem to be right hand thread in all of the photos. The smaller antennas are almost certainly for L1. The complication is the Block-IIR-M-SV-2S photo. But it has *three* sizes of antennas visible. The largest are left-hand-thread quadhelix as before, and thus likely close to the same physical dimensions as the large antennas in the other photos. The mid-size ones are multi-element multi-turn helixes that look a lot like the quadhelixes in design except that the ends are left open. And they are about 2/3 the diameter of the quadhelixes, much larger than the simple helix antennas in the previous group, so probably for a different frequency. Then there are the smallest antennas, which appear to be a single-element helix with many many turns - but these are about 1/3 the diameter of the large quadhelixes, and thus *these* are likely the L1 antennas. And, if I look closely, these small helixes do appear to be right-hand-thread wound. Well, the traditional Block-II antennas had an inner and and outer ring, at it was made so on purpose to create a antenna-lobe such that it would direct more power towards the edge of the globe than straight down, such that the distance difference and hence the damping is first degree compensated such that the signal strength depending on azimuth is more even. I could dig up the reference if I where at home, but I recall it since I think it is kind of neat engineering. Good that you guys set me straight on the orientation-stuff. Cheers, Magnus ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
t...@leapsecond.com said: http://www.ausairpower.net/Block-IIR-M-SV-1S.jpg What is the significance of the pointy tops of the long skinny antennas? How about the collars at the base of them? -- These are my opinions. I hate spam. ___ 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] GPS through windows
Does window glass have significant attenuation at GPS L1? What if it's a big window on a modern green office building and has some sort of coating/content to reduce IR transmission? Google found an (expensive) paper from IEEE where the abstract said: At average, about 30 dB attenuation is observed from 800 MHz to 6 GHz so I assume the answer is mostly sure does. Does anybody have more info? Is there a rule of thumb? (maybe X dB, or X dB/inch) Does it vary wildly from brand to brand of glass? -- Context is that I took some low cost consumer GPS toys when I visited a friend who had recently moved into a new office building. He's on the 4th floor, well above anything else on that side, so we had a clear view for half of the sky looking West or slightly North of West. We tried a SiRF III and a Sure demo board. I had forgotten to update the Sure clock the night before so it was having a hard time getting off the ground. We took everything outside where they locked up within a few minutes. Back inside with the antennas on a window sill, both just barely worked some of the time. The glass below the sill was a different color, slightly less yellow. We tried the lower (floor level) sill but didn't notice any difference. That wasn't a serious test with numbers and error bars, but we probably would have noticed if it had suddenly started working much better. -- These are my opinions. I hate spam. ___ 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 through windows
Part of the problem of using a window would remain even if the glass where removed. This is the antenna can not see the entire sky from a window. You can do ok if the window faces South (assume you are in the Northern Hemisphere) With a good timing GPS receiver you only need to see a very small number of satellites. So the window can work but you would get better results if you can see the horizon all 360 degrees around. Is there no access to the roof? What about the roof of some other building. Place the antenna and the receiver on the roof and send the data back via some kind of link. Using a higher gain antenna might (make up for any attenuation cause be coating on the glass. So it might work. On Mon, Jun 4, 2012 at 10:24 PM, Hal Murray hmur...@megapathdsl.net wrote: Does window glass have significant attenuation at GPS L1? What if it's a big window on a modern green office building and has some sort of coating/content to reduce IR transmission? Google found an (expensive) paper from IEEE where the abstract said: At average, about 30 dB attenuation is observed from 800 MHz to 6 GHz so I assume the answer is mostly sure does. Does anybody have more info? Is there a rule of thumb? (maybe X dB, or X dB/inch) Does it vary wildly from brand to brand of glass? -- Context is that I took some low cost consumer GPS toys when I visited a friend who had recently moved into a new office building. He's on the 4th floor, well above anything else on that side, so we had a clear view for half of the sky looking West or slightly North of West. We tried a SiRF III and a Sure demo board. I had forgotten to update the Sure clock the night before so it was having a hard time getting off the ground. We took everything outside where they locked up within a few minutes. Back inside with the antennas on a window sill, both just barely worked some of the time. The glass below the sill was a different color, slightly less yellow. We tried the lower (floor level) sill but didn't notice any difference. That wasn't a serious test with numbers and error bars, but we probably would have noticed if it had suddenly started working much better. -- These are my opinions. I hate spam. ___ 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. -- 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
Slightly off-topic, the first time I was aware of polarisation error was during the very first trans-Atlantic TV tests. On the first night, signals were fine in France (who had a copy of the US antenna), but poor in the UK who had designed and built their own antenna). UK changed polarisation for the next night and signals were then fine. All this live on public TV (when everyone watched, and there we're 500 poor-quality channels vying for your attention). http://www.smecc.org/w_j_bray_-_uk.htm http://www.rfcmd.com/index.php?option=com_contentview=articleid=305%3Athe-first-satellite-dish-catid=56%3AtelecommunicationsItemid=18lang=en Cheers, David -- SatSignal software - quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ 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] Antenna question about RHCP/LHCP I'm sure a time-nutcan answer
On Mon, Jun 4, 2012 at 10:18 PM, Hal Murray hmur...@megapathdsl.net wrote: What is the significance of the pointy tops of the long skinny antennas? Guessing. Terminates the end of the conductor to prevent a discontinuity and reflection How about the collars at the base of them? Another guess: They kill multi path reflections from supporting structure Now let's see what the experts say 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.
