Re: [time-nuts] GPS backup for the stationary time and frequencyuser
On 10/08/2010 08:09 PM, Brooke Clarke wrote: Hi John: The WAAS birds may be too weak to receive with an omni antenna, hence the desire to get some gain. The normal GPS sats will pass through the beam and the GPS antenna will pick up some sats directly so you do get some TRAIM. Doppler is not an issue in timing mode (i.e. position is known) and only one sat is required. The WAAS/EGNOS/SBAS power should be equal to the GPS birds, such that a normal GPS receiver can receive them on the same antenna, the code is such that a standard GPS receiver channel can lock to it, the big difference lies in the rate and encoding of the data-channel. Calls for some extra software including a standard Viterbi-decoder. 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] 60 KHz Receiver
Well I remember them at least I think we are speaking of the same domes. The ones I am thinking of are just south of moffet field though those were actually dishes. Anyhow being a bit interested and in the navy at the time. Drove on to moffet field no problem with a navy truck and drove through an additional area. Got pretty close. But don't know why someone did not like it and escorted the poor dumb guy out of the area. That was a kinder gentler time. Today you truly would be screwed. Regards On Fri, Oct 8, 2010 at 11:05 PM, Rex r...@sonic.net wrote: You mean near the intersection of 401 and 537? Close to 385 also. (I took the liberty of keeping up the code and adding 300 to everything.) -Rex On 10/8/2010 6:26 PM, J. Forster wrote: Where? Off 401 near the Blue Cube? -John = We had similar dome in Sunnyvale (Ca)Â until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave ___ 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] 60 KHz Receiver
Hi Dave: Yes, it was right on the central expressway and was part of the GTE military electronics complex. Hi John: My recollection of the antennas at the Blue Cube is that they are out in the open. See photo at: http://en.wikipedia.org/wiki/Blue_Cube Have Fun, Brooke Clarke http://www.PRC68.com d.sei...@comcast.net wrote: We had similar dome in Sunnyvale (Ca) until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave - Original Message - From: Arthur Dentgolgarfrinc...@yahoo.com To: time-nuts@febo.com Sent: Friday, October 8, 2010 5:06:34 AM Subject: [time-nuts] 60 KHz Receiver Lester Veenstra-“No, Andover Maine.” The white Dacron fabric dome of the station in Andover, Maine, really stood out and could be seen by hikers on the tops of mountains miles away. Somewhere I have photos I took looking down at that white speck in the distance. On one of my hiking trips I stopped to check out the facility. The Dacron fabric dome that was held up only by air pressure (like a carnival funhouse) was still standing but was scheduled to be taken down in the near future. Below is a link to a video about Telstar that appeared on the History Channel and another link to still photos of the horn and the inside of the dome. The date given for removal in the second link was 1985 but I was thinking the dome was removed a few years later than that. http://www.youtube.com/watch?v=NyfGuSmSHWM http://users658.mainememory.net/slideshow/386/display%3Fformat=listprev_object_id=1050prev_object=pageslide_num=1.html -Arthur ___ 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. -- Have Fun, Brooke Clarke http://www.PRC68.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] GPS backup for the stationary time and frequencyuser
On 10/8/2010 1:48 PM, Magnus Danielson wrote: I would not be supprised if they had not considered such a threat. This is a common threat for all bent-pipe birds. They have been jammed before and we can expect them to be jammed again. However, I do not think the WAAS or any similar is highest up on the target list as for most uses it is a support-function rather than main function system. Birds which has been jammed is typically TV signal relays. Threat model is different here. The end-user terminals for TV sats have narrow antennas looking at just that satellite, so it affects just that satellite/transponder. The end-user terminals for GPS are looking at the entire hemisphere of sky, so if you can send spoofed signals from the WAAS transponder (same RF frequency that all the rest of the GPS satellites are using to talk to single-frequency receivers) and get the receivers to lock to these signals instead of the legitimate ones, you can interfere with *all* GPS reception, not just the WAAS signal, for the entire coverage area of WAAS. Matthew Kaufman ___ 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 backup for the stationary time and frequencyuser
Hi Magnus: Stanford Telecom built GPS simulators to test their GPS ICs. It's made where each wire wrap PCB is based on a page from ICD-200. http://www.prc68.com/I/5001A.html Have Fun, Brooke Clarke http://www.PRC68.com Magnus Danielson wrote: On 10/09/2010 04:47 PM, Matthew Kaufman wrote: On 10/8/2010 1:48 PM, Magnus Danielson wrote: I would not be supprised if they had not considered such a threat. This is a common threat for all bent-pipe birds. They have been jammed before and we can expect them to be jammed again. However, I do not think the WAAS or any similar is highest up on the target list as for most uses it is a support-function rather than main function system. Birds which has been jammed is typically TV signal relays. Threat model is different here. The end-user terminals for TV sats have narrow antennas looking at just that satellite, so it affects just that satellite/transponder. Indeed. The end-user terminals for GPS are looking at the entire hemisphere of sky, so if you can send spoofed signals from the WAAS transponder (same RF frequency that all the rest of the GPS satellites are using to talk to single-frequency receivers) and get the receivers to lock to these signals instead of the legitimate ones, you can interfere with *all* GPS reception, not just the WAAS signal, for the entire coverage area of WAAS. Hmm. Yes. Creative! Once demonstrated essentially all WAAS/EGNOS/SBAS sats need to develope some protective measure. To pull it off, a standard GPS simulator and some minor frequency conversion is needed. Should not stop the handy man. It would be an interesting legal aspect to attempt to charge the guilty... 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. -- Have Fun, Brooke Clarke http://www.PRC68.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] GPS backup for the stationary time and frequencyuser
On 10/9/2010 8:00 AM, Magnus Danielson wrote: Hmm. Yes. Creative! Once demonstrated essentially all WAAS/EGNOS/SBAS sats need to develope some protective measure. Unless, of course, such protective measures already exist. I can think of several ways right off the top of my head... one would be to have the transponder be able to shut itself down if it doesn't appear to be relaying a single valid code stream... another would be to have ensured that the maximum power density was low enough that anything with enough real satellites in view couldn't be practically interfered with... another is to have ground-based monitoring and a transponder enable system that can't simply be jammed into the on mode but rather requires a key be sent require regularly to keep the transponder powered up... I just haven't seen anything in the literature noting that the threat had been looked at and/or addressed in any way. To pull it off, a standard GPS simulator and some minor frequency conversion is needed. Should not stop the handy man. Indeed. It would be an interesting legal aspect to attempt to charge the guilty... If there's 1 space-based receiver on the uplink frequency, you can fairly easily find any source that has an uplink beam wide enough to illuminate more than one of them. Failing that there's other ways to find the source that take longer. Once found, I think there's adequate law and precedent for going after someone who interferes with safety-of-life transmissions. But there could be quite a bit of damage (even as simple as lost productivity from truck drivers who couldn't make timely deliveries until they found some printed maps) in the meantime. Matthew Kaufman ___ 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] 60 KHz Receiver
The reason for the dishes could well have been for comunications with the Blue Cube as that place was/is? the headquarters for the Air Force Satellite Control Facility. Maybe you remember The Brass Rail... the nudie bar across the street from the Lockheed main gate? -John Well I remember them at least I think we are speaking of the same domes. The ones I am thinking of are just south of moffet field though those were actually dishes. Anyhow being a bit interested and in the navy at the time. Drove on to moffet field no problem with a navy truck and drove through an additional area. Got pretty close. But don't know why someone did not like it and escorted the poor dumb guy out of the area. That was a kinder gentler time. Today you truly would be screwed. Regards On Fri, Oct 8, 2010 at 11:05 PM, Rex r...@sonic.net wrote: You mean near the intersection of 401 and 537? Close to 385 also. (I took the liberty of keeping up the code and adding 300 to everything.) -Rex On 10/8/2010 6:26 PM, J. Forster wrote: Where? Off 401 near the Blue Cube? -John = We had similar dome in Sunnyvale (Ca)Â until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave ___ 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 backup for the stationary time and frequencyuser
Matthew Kaufman wrote: On 10/9/2010 8:00 AM, Magnus Danielson wrote: Hmm. Yes. Creative! Once demonstrated essentially all WAAS/EGNOS/SBAS sats need to develope some protective measure. Unless, of course, such protective measures already exist. I can think of several ways right off the top of my head... one would be to have the transponder be able to shut itself down if it doesn't appear to be relaying a single valid code stream... another would be to have ensured that the maximum power density was low enough that anything with enough real satellites in view couldn't be practically interfered with... another is to have ground-based monitoring and a transponder enable system that can't simply be jammed into the on mode but rather requires a key be sent require regularly to keep the transponder powered up... that would assume that the WAAS transponders are actually purpose designed, and not just a generic bent pipe that was repurposed from something else. If it's purpose designed, it's easy.. the uplink signal doesn't have to look anything like the downlink signal. You could, for instance, send up two signals which have to be combined on board to make the downlink signal. For the initial WAAS, they may have just leased transponders that already existed.. which would be vulnerable, after a fashion. There are a variety of AJ measures taken by the satellite operators (no more Capt. Midnight stuff) I just haven't seen anything in the literature noting that the threat had been looked at and/or addressed in any way. Unlikely that this would be in the open literature. It's pretty clearly one of those things that falls under export control. To pull it off, a standard GPS simulator and some minor frequency conversion is needed. Should not stop the handy man. Indeed. ___ 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] 60 KHz Receiver
About the only doors in the place that did not have electronic combo locks were the bathrooms. Sad to see it's being shut down. IMO, it was one of the kewl places to be in the heddy early days of space. OTOH, it probably makes some sense to muve the thing into the bowels of a mountain somewhere. FWIW, -John == Hi Dave: Yes, it was right on the central expressway and was part of the GTE military electronics complex. Hi John: My recollection of the antennas at the Blue Cube is that they are out in the open. See photo at: http://en.wikipedia.org/wiki/Blue_Cube Have Fun, Brooke Clarke http://www.PRC68.com d.sei...@comcast.net wrote: We had similar dome in Sunnyvale (Ca) until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave - Original Message - From: Arthur Dentgolgarfrinc...@yahoo.com To: time-nuts@febo.com Sent: Friday, October 8, 2010 5:06:34 AM Subject: [time-nuts] 60 KHz Receiver Lester Veenstra-âNo, Andover Maine.â The white Dacron fabric dome of the station in Andover, Maine, really stood out and could be seen by hikers on the tops of mountains miles away. Somewhere I have photos I took looking down at that white speck in the distance. On one of my hiking trips I stopped to check out the facility. The Dacron fabric dome that was held up only by air pressure (like a carnival funhouse) was still standing but was scheduled to be taken down in the near future. Below is a link to a video about Telstar that appeared on the History Channel and another link to still photos of the horn and the inside of the dome. The date given for removal in the second link was 1985 but I was thinking the dome was removed a few years later than that. http://www.youtube.com/watch?v=NyfGuSmSHWM http://users658.mainememory.net/slideshow/386/display%3Fformat=listprev_object_id=1050prev_object=pageslide_num=1.html -Arthur ___ 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. -- Have Fun, Brooke Clarke http://www.PRC68.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] GPS backup for the stationary time and frequencyuser
On 10/9/2010 8:22 AM, jimlux wrote: Unlikely that this would be in the open literature. It's pretty clearly one of those things that falls under export control. Quite likely. The threat itself hasn't been mentioned as far as I can tell, either... as someone who relies on GPS timing for several telecom and network applications, including one where time disruptions can be security disruptions, it is definitely something to think about and add to the list of risks. Matthew Kaufman ___ 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 backup for the stationary time and frequencyuser
Hi The Russians have been willing to sell GPS jammers for quite a while. They aren't terribly expensive. Their export controls are a bit different than the US's. Bob On Oct 9, 2010, at 12:00 PM, Matthew Kaufman wrote: On 10/9/2010 8:22 AM, jimlux wrote: Unlikely that this would be in the open literature. It's pretty clearly one of those things that falls under export control. Quite likely. The threat itself hasn't been mentioned as far as I can tell, either... as someone who relies on GPS timing for several telecom and network applications, including one where time disruptions can be security disruptions, it is definitely something to think about and add to the list of risks. Matthew Kaufman ___ 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 backup for the stationary time and frequencyuser
But unlike the threat I described, they're not pre-mounted in geo orbit over the US... As far as we know. Matthew Kaufman (Sent from my iPhone) On Oct 9, 2010, at 9:16 AM, Bob Camp li...@rtty.us wrote: Hi The Russians have been willing to sell GPS jammers for quite a while. They aren't terribly expensive. Their export controls are a bit different than the US's. Bob On Oct 9, 2010, at 12:00 PM, Matthew Kaufman wrote: On 10/9/2010 8:22 AM, jimlux wrote: Unlikely that this would be in the open literature. It's pretty clearly one of those things that falls under export control. Quite likely. The threat itself hasn't been mentioned as far as I can tell, either... as someone who relies on GPS timing for several telecom and network applications, including one where time disruptions can be security disruptions, it is definitely something to think about and add to the list of risks. Matthew Kaufman ___ 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] 60 KHz Receiver
Hi John: Was at the Brass Rail decade ago. Later read the Russians were also there during the cold war. Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: The reason for the dishes could well have been for comunications with the Blue Cube as that place was/is? the headquarters for the Air Force Satellite Control Facility. Maybe you remember The Brass Rail... the nudie bar across the street from the Lockheed main gate? -John Well I remember them at least I think we are speaking of the same domes. The ones I am thinking of are just south of moffet field though those were actually dishes. Anyhow being a bit interested and in the navy at the time. Drove on to moffet field no problem with a navy truck and drove through an additional area. Got pretty close. But don't know why someone did not like it and escorted the poor dumb guy out of the area. That was a kinder gentler time. Today you truly would be screwed. Regards On Fri, Oct 8, 2010 at 11:05 PM, Rexr...@sonic.net wrote: You mean near the intersection of 401 and 537? Close to 385 also. (I took the liberty of keeping up the code and adding 300 to everything.) -Rex On 10/8/2010 6:26 PM, J. Forster wrote: Where? Off 401 near the Blue Cube? -John = We had similar dome in Sunnyvale (Ca)Â until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave ___ 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. -- Have Fun, Brooke Clarke http://www.PRC68.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] 60 KHz Receiver
I have no doubt it's be a good snooping ground for the Ruskies. Lotsa guys from spooky places, booze, and naked women. Lunchtime featured a gal with a big snake... and little else. LoL. -John Hi John: Was at the Brass Rail decade ago. Later read the Russians were also there during the cold war. Have Fun, Brooke Clarke http://www.PRC68.com J. Forster wrote: The reason for the dishes could well have been for comunications with the Blue Cube as that place was/is? the headquarters for the Air Force Satellite Control Facility. Maybe you remember The Brass Rail... the nudie bar across the street from the Lockheed main gate? -John Well I remember them at least I think we are speaking of the same domes. The ones I am thinking of are just south of moffet field though those were actually dishes. Anyhow being a bit interested and in the navy at the time. Drove on to moffet field no problem with a navy truck and drove through an additional area. Got pretty close. But don't know why someone did not like it and escorted the poor dumb guy out of the area. That was a kinder gentler time. Today you truly would be screwed. Regards On Fri, Oct 8, 2010 at 11:05 PM, Rexr...@sonic.net wrote: You mean near the intersection of 401 and 537? Close to 385 also. (I took the liberty of keeping up the code and adding 300 to everything.) -Rex On 10/8/2010 6:26 PM, J. Forster wrote: Where? Off 401 near the Blue Cube? -John = We had similar dome in Sunnyvale (Ca)Â until the late 80's, but I can't remember who owned it, maybe GE?; it's all housing now. Dave ___ 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. -- Have Fun, Brooke Clarke http://www.PRC68.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] 60 KHz Receiver
On 10/9/2010 7:40 AM, Brooke Clarke wrote: Hi Dave: Yes, it was right on the central expressway and was part of the GTE military electronics complex. That building existed from 1963 until 1990 at the GTE Sylvania complex that was at 500 Evelyn... right at Central Expressway and 237. Can't dig up any good photos of it in a cursory search, though. Matthew Kaufman ___ 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] 60 KHz Receiver
On 10/9/2010 11:43 AM, Matthew Kaufman wrote: On 10/9/2010 7:40 AM, Brooke Clarke wrote: Hi Dave: Yes, it was right on the central expressway and was part of the GTE military electronics complex. That building existed from 1963 until 1990 at the GTE Sylvania complex that was at 500 Evelyn... right at Central Expressway and 237. Can't dig up any good photos of it in a cursory search, though. 37 23 19.60 N x 122 03 27.00 W and visible on Google Earth if you switch to the October 1991 image set. Matthew Kaufman ___ 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] 60kHz shielded loop antenna
Have you considered an H Field Loop antenna. We built a quantity of these to dramatically increase sensitivity and reduce EMI on our LF tracking RXs (now obsolete) Some details are still on our web site under RF microwave components. Yours Clive Green CEO Quartzlock + Gothic, Plymouth Road, Totnes, Devon. TQ9 5LH England (: +44 (0) 1803 862 062 7: +44 (0) 1803 867 962 : mailto:n...@quartzlock.com cgr...@quartzlock.com ü: http://www.quartzlock.com www.quartzlock.com Skype: clive.green.skype Messenger: cgr...@quartzlock.com Registered office: Gothic, Plymouth Road, Totnes, Devon. TQ9 5LH England Registered in England P Think Environment, print only if necessary. This is an e-mail from Quartzlock (UK) Limited, its contents (including all attachments) and any files transmitted with it are confidential and intended solely for the individual(s) to which it is addressed and may also be privileged. It may not be copied or printed by anyone other than the addressee and may not be disclosed or distributed in any way. If you have received this e-mail in error please inform Quartzlock (UK) Limited and delete it from your mailbox or any other storage devices. Although this e-mail and any attachments are believed to be free of any virus or other defects which might affect any computer or IT system into which they are received, no responsibility is accepted by Quartzlock (UK) Limited or any of its directors, staff or associated businesses or contacts for any loss or damage arising in any way from the receipt or use thereof. Opinions, conclusions and other information expressed in this message are not given or endorsed by Quartzlock (UK) Limited unless otherwise indicated by an authorised representative independent of this message. ___ 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 backup for the stationary time and frequencyuser
Bob Camp wrote: Hi The Russians have been willing to sell GPS jammers for quite a while. They aren't terribly expensive. Their export controls are a bit different than the US's. Bob Simple GPS jammers are pretty easy, since consumer GPS is very vulnerable to repeater jammers. Hmm I wonder if that would adversely affect a GPSDO? Probably not, since the repeated signal is just as stable as the original one. jammers probably aren't subject to export controls, just local usage regulations (e.g. illegal in US because of FCC rules prohibiting them). the ITAR (which is the big deal in the export controls world, compared to EAR) is the *International* Tariff, so everyone is a signatory, and we're all in the same boat as to what is a munition and what is not. Granted, enforcement and interpretation varies. ___ 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] HP/Dymek DY-5842-- WARNING... Manual is back, All is OK now.
Since this warning made the list, it must be answered in the list: Scott McGrath returned my HP5065B manual (by FedEx, no less). It is back safe and sound. All is well. Thanks Scott! -Chuck Harris Chuck Harris wrote: PM sent. -Chuck scmcgr...@gmail.com wrote: Yes I do have the manual - I also travel to all corners of the known universe and if I'm home I might be there for 24-48 hours. I finally got it scanned and sent a copy to chuck. I overestimated my ability to scan and return the manual in a timely fashion. I also have paid for and never taken delivery of equipment for the same reason in many cases running into thousands of dollars. I've lost stuff shipped to the UPS store because I have not been able to claim it in time. Chuck and the list I apologize for holding on to your manual for so long every time I come home I see it sitting in its box on my desk like the damn sword of damocles. Tell me where you want it to go because I am home for at least one day Scott Sent from my Verizon Wireless BlackBerry ___ 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] HP/Dymek DY-5842-- WARNING... Manual is back, All is OK now.
Chuck, I'm glad you finally got it back. Best, -John === Since this warning made the list, it must be answered in the list: Scott McGrath returned my HP5065B manual (by FedEx, no less). It is back safe and sound. All is well. Thanks Scott! -Chuck Harris Chuck Harris wrote: PM sent. -Chuck scmcgr...@gmail.com wrote: Yes I do have the manual - I also travel to all corners of the known universe and if I'm home I might be there for 24-48 hours. I finally got it scanned and sent a copy to chuck. I overestimated my ability to scan and return the manual in a timely fashion. I also have paid for and never taken delivery of equipment for the same reason in many cases running into thousands of dollars. I've lost stuff shipped to the UPS store because I have not been able to claim it in time. Chuck and the list I apologize for holding on to your manual for so long every time I come home I see it sitting in its box on my desk like the damn sword of damocles. Tell me where you want it to go because I am home for at least one day Scott Sent from my Verizon Wireless BlackBerry ___ 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 backup for the stationary time and frequencyuser
On 10/09/2010 09:47 PM, jimlux wrote: Bob Camp wrote: Hi The Russians have been willing to sell GPS jammers for quite a while. They aren't terribly expensive. Their export controls are a bit different than the US's. Bob Simple GPS jammers are pretty easy, since consumer GPS is very vulnerable to repeater jammers. Hmm I wonder if that would adversely affect a GPSDO? Probably not, since the repeated signal is just as stable as the original one. Well, a real jammer will just prohibit the reception of signal while a spoofing attempt would provide a false signal. There is no reason to assume that a spoofed signal would be stable. Also, the spoofing attempt we talked about through the WAAS bent-pipe does not necessarily make the GPS receiver lock onto all the spoofed signals, but a shifting selection of correct and spoofed signals. RAIM in receivers would help to some degree, If it fully locks on to the spoofing signal, just to be thrown away in time and that should upset most GPSDOs quite a bit. jammers probably aren't subject to export controls, just local usage regulations (e.g. illegal in US because of FCC rules prohibiting them). the ITAR (which is the big deal in the export controls world, compared to EAR) is the *International* Tariff, so everyone is a signatory, and we're all in the same boat as to what is a munition and what is not. Granted, enforcement and interpretation varies. Someone seriously wanting to use one for some reason would not care significantly and found ways around it. Someone with sufficient knowledge would build one if needing to. 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] GPS backup for the stationary time and frequencyuser
On Oct 9, 2010, at 12:47 PM, jimlux wrote: Simple GPS jammers are pretty easy, since consumer GPS is very vulnerable to repeater jammers. Hmm I wonder if that would adversely affect a GPSDO? Probably not, since the repeated signal is just as stable as the original one. I would think that with a little bit more effort, one could make a fairly simple repeater jammer that broadcasts a substantially less stable signal. With a suitable slack buffer between the receiver and transmitter, the retransmission delay doesn't need to be constant or even predictable, thus messing with apparent time and frequency. With still more effort, one could detect individual satellite signals and retransmit them separately with different and varying delays, thus messing with the apparent position relationships of the birds at any point in time. -- Mark J. Blair, NF6X n...@nf6x.net Web page: http://www.nf6x.net/ GnuPG public key available from my web page. ___ 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.
