Re: [time-nuts] Acquired a Symmetricom 5817A-05Q / Power connector Question
I added a couple more pictures of the connector after removing it from the housing I tired to get a better close up on the connector, but it's kind of blurry. After more research, it's an SMC F, female actually... I guess. I assumed male because of the pin inside the plastic / dielectric. http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Anyway, I found some good pictures of a possible replacement on flea/Bay/eBay: http://www.ebay.com/itm/Lot-of-2-ITT-050-045--220-Conn-SMC-F-12-4GHz-50Ohm-Solder-Pot-ST-Pnl-Mnt-NEW-/271840415566?pt=LH_DefaultDomain_0hash=item3f4af38f4e Look at the 4th picture. I'm kind of anal about fixing this kind of stuff, even if I end up going the 0 ohm jumper route and disable the power input to use power from the one of my GPS receivers. Thanks once again... I would have spent a lot more time on my own getting to the bottom of it. 73 de Max NG7M On Sat, May 9, 2015 at 12:25 PM, M. George m.matthew.geo...@gmail.com wrote: Thanks for all the replies everyone, very helpful as usual. the links that Oz posted seem to match up with the connector on my 5817a. http://www.amphenolrf.com/media/wysiwyg/SMC_4.jpg Its the male side of a SMC connector. I'll remove the broken one from the unit... take a few more pictures. All the comments on bypassing the power input option were very helpful too. i.e. the 05Q option. I figured that should be pretty easy where they sold this unit without the external power option. Again, thanks for the detailed responses gents! Max NG7M On Sat, May 9, 2015 at 11:32 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: That is supposed to be an SMB connector, that is what I have on mine. You can drop in a 0-ohm so that you can feed it and the antenna from Port 1. It might be a quicker solution for you. Cheers, Magnus On 05/09/2015 02:27 PM, Bob Camp wrote: Hi Only going by the pictures, that looks like the remains of a broken SMB connector. Bob On May 8, 2015, at 10:11 PM, M. George m.matthew.geo...@gmail.com wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M -- M. George ___ 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. -- M. George -- M. George ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
On 5/9/2015 10:32 AM, Magnus Danielson wrote: That is supposed to be an SMB connector, that is what I have on mine. You can drop in a 0-ohm so that you can feed it and the antenna from Port 1. It might be a quicker solution for you. Cheers, Magnus Magnus it needs more than that to convert to the standard version. I have offered Max a picture of mine to compare. It needs an RF choke added, the 180 Ohm R removed and four bypass caps added to the empty positions where the 180 Ohm is. Dan ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
Thanks for all the replies everyone, very helpful as usual. the links that Oz posted seem to match up with the connector on my 5817a. http://www.amphenolrf.com/media/wysiwyg/SMC_4.jpg Its the male side of a SMC connector. I'll remove the broken one from the unit... take a few more pictures. All the comments on bypassing the power input option were very helpful too. i.e. the 05Q option. I figured that should be pretty easy where they sold this unit without the external power option. Again, thanks for the detailed responses gents! Max NG7M On Sat, May 9, 2015 at 11:32 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: That is supposed to be an SMB connector, that is what I have on mine. You can drop in a 0-ohm so that you can feed it and the antenna from Port 1. It might be a quicker solution for you. Cheers, Magnus On 05/09/2015 02:27 PM, Bob Camp wrote: Hi Only going by the pictures, that looks like the remains of a broken SMB connector. Bob On May 8, 2015, at 10:11 PM, M. George m.matthew.geo...@gmail.com wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M -- M. George ___ 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. -- M. George ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
Honestly, that looks broken to me. And, it looks more like a broken SMA jack (at least from the photos). I would say your best bet is to open the thing up and replace the connector with something a bit more workable. Happy tweaking. On 09-May-15 05:58, Oz-in-DFW wrote: On 5/8/2015 9:11 PM, M. George wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below -- --- Bruce Lane, ARS KC7GR http://www.bluefeathertech.com kyrrin (at) bluefeathertech dot com Quando Omni Flunkus Moritati (Red Green) ___ 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] TymServe 2100 1995 Issue - A Kludgy Fix
Hi As far as I can see, the 13 bit week stuff is still very much in the “testing” phase. I’d say that counting on it working on anything made before 2013 is a bit of a stretch. I would also bet that roughly 90% of the “current” timing GPS chip set designs do not yet fully support it. That might change with a firmware upgrade (if one ever comes out for your chip set etc.). Based on how well things like leap years seem to get taken care of, we’ll really only know in 20 years or so. Yes it’s a bit confusing, it’s all snarled up in the “block III will be here in 2008” ... err…2014 … err …2017 …errr... confusion. Bob On May 6, 2015, at 12:04 PM, Brian Inglis brian.ing...@systematicsw.ab.ca wrote: On 2015-05-05 11:32, Alan Ambrose wrote: It's not that simple. First, it's not 20 years, but 1024 weeks (19.6 years). And not UTC weeks (which may have leap seconds) but GPS weeks (which do not, and are always 604800 seconds long). etc Don't think it's _that_ much code though. There's some open source ACM date algorithms, and it would be easy enough to implement a quick and dirty fix, adding a number of days offset, while the rest of the algorithm is tested. See http://www.leapsecond.com/notes/gpswnro.htm This was first noted in 1996 and has been happening since the first rollover in August 1999 so some affected NTP GPS drivers have been patched to add 1024 weeks while the input is more than 512 weeks in the past. Will the next time this problem reoccurs be another 20 years? The next rollover is about April 2019, but this can happen any time an older receiver's internal date representation used for GPS to UTC conversion overflows. Looks like Tymserve 2100 picked about Sep 1995 for its date epoch so it hits now. Newer GPS receivers support the extra 3 bits added to GPS extended week allowing 8192 weeks (157 years) between rollovers - 2137 is the next big rollover problem, but NavStar will likely not be sending the same data on the same frequency then. -- Take care. Thanks, Brian Inglis ___ 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] lawnmower robots may be the end of VLF timekeeping
Bob Widlar -- yes the designer of the 741 -- of National Semiconductor had a better idea, he bought a few sheep 73 KJ6UHN Alex On 5/9/2015 2:02 PM, Mark Sims wrote: iRobot (the Roomba vacuum cleaner people) have applied for an exemption to allow them to send beacon signals in a 6-7 GHz band to fence in their new lawnmower. The band they want to operate in is apparently for indoor only low power applications. The easy solution is to just buy some goats... the emit very little in the way of EMI... but do emit other, u, signals. -- Clearly, you need a better nav system for the robot based on precision time of flight measurements from a network of transmitters around the property linked to your hydrogen maser. ___ 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] lawnmower robots may be the end of VLF timekeeping
http://www.blitzortung.org/Webpages/index.php?lang=en typo correction. John -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Björn Sent: Saturday, May 09, 2015 2:15 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] lawnmower robots may be the end of VLF timekeeping The same has been observed by the lightning listeners at blitzortnung.org -- Björn div Originalmeddelande /divdivFrån: Poul-Henning Kamp p...@phk.freebsd.dk /divdivDatum:2015-05-09 14:15 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] lawnmower robots may be the end of VLF timekeeping /divdiv /divI spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html -- 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. --- This email has been checked for viruses by Avast antivirus software. 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] lawnmower robots may be the end of VLF timekeeping
Poul-Henning Kamp kirjoitti: I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html In the Finland that problem is even worse! For me it's called Savon Voima, our local power company (but also many other power companies around the Finland). They are using PLC based remote readable utility meters. These meters communicate with power lines, using ancient 1200 bps. FSK using 83.2/93.6 kHz frequencies. Because the power grid is not designed for this kind of communication, those frequencies will of course leak all over the places. Because the metering hardware is cheap crap made by Slovenian company, those frequencies are not very accurate/narrow and so they block the DCF77 77,5 kHz band totally! Because all in-house wiring act as an transmitter antennas, the field strenghts inside the houses can be as high as 120 dBuV/m. The system is so stupid that it need to communicate 24h to transfer less than six digits (the reading of the utility meter), which is basicly needed once per month for elecricity billing. Every meter can act as repeater to other meters. The DCF77 problem was verified when there was large blackout. During this blackout the DCF77 clocks was syncronized at moments, when they never synchronize normally. When this was reported to Finnish authority called Viestintävirasto (it's Finnish version of FCC), they say that this doesn't matter - the DCF77 is not protected in Finland (even when you can buy radio controlled clocks from the shop). The whole idea about PLC is so stupid and the universal stupidity factor of the people designing these is so high that there's nothing to do anymore. Even the power company said that this is not reliable system, having much of interferences, the readings are not transferred succesfully all the times. But still they buy this kind of crap, even when knowing it weaknesses. Clearly the marketing guys of PLC systems knows their business and they can even cope with local auhorities so that there's no problems to install these everywhere. I think that we have lost the game! Only way to set the clock is to build your own DCF77 transmitter - like the local authority said: the DCF77 band is not protected - at least here in Finland... -- 73s! Esa OH4KJU ___ 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] lawnmower robots may be the end of VLF timekeeping
Hi The real questions: 1) Are they breaking any laws with their pollution? 2) Is there a regulatory body that is charged with enforcing those laws? 3) Is the cost (hours / dollars / hassle) of taking action prohibitive? Often it’s a combination of more than one that gets you … This is fundamentally no different than the boys setting up their system right next to GPS. The main difference is that they had to go through the licensing process and not all these devices do that. I do know that when every radio clock within 1/2 Km goes dead, there are towns that will have a lot of people scratching their heads …. Bob On May 9, 2015, at 2:15 PM, Björn b...@lysator.liu.se wrote: The same has been observed by the lightning listeners at blitzortnung.org -- Björn div Originalmeddelande /divdivFrån: Poul-Henning Kamp p...@phk.freebsd.dk /divdivDatum:2015-05-09 14:15 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] lawnmower robots may be the end of VLF timekeeping /divdiv /divI spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html -- 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. ___ 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] lawnmower robots may be the end of VLF timekeeping
iRobot (the Roomba vacuum cleaner people) have applied for an exemption to allow them to send beacon signals in a 6-7 GHz band to fence in their new lawnmower. The band they want to operate in is apparently for indoor only low power applications. The easy solution is to just buy some goats... the emit very little in the way of EMI... but do emit other, u, signals. -- Clearly, you need a better nav system for the robot based on precision time of flight measurements from a network of transmitters around the property linked to your hydrogen maser. ___ 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] EMI and CE certification (was: lawnmower robots may be the end of VLF timekeeping)
On Sat, 09 May 2015 12:15:47 + Poul-Henning Kamp p...@phk.freebsd.dk wrote: I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html Uh.. nice...and welcome to the world of self-certification. I'm pretty sure these devices are not properly EMI tested or rather, they were, but the manufacturer cheated (as everyone does with this kind of stuff). You can, and IMHO should report these kind of EMI to the proper authorities. Devices like this should not be sold and in nost european countires are actually illegal (there is a law against knowingly transmit in a band you are not licensed for). I don't know other countries, but at least in Switzerland, the BAKOM is usually quite happy to hear about these things, and test devices in their own lab... with nice fines for the offending company for not properly testing their products. Attila Kinali -- _av500_ phd is easy _av500_ getting dsl is hard ___ 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] Important parameters for a GPS/GNSS antenna
In message fc02a5e8-5396-4474-a307-546e10909...@n1k.org, Bob Camp writes: The “put the antenna up and rotate it to see what happens” experiment has indeed been done. The objective was not correcting the antenna’s issues, but validating that their model of the antenna’s phase center was correct. They were trying to see if anechoic chamber data really gave correct answers in free space. So this could be a realistic way for us to calibrate the phase-center of an antenna ? -- 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
m.matthew.geo...@gmail.com said: Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! The white tube looks like insulation from coax. Have you tried taking the connector apart? You might poke around with an ohmmeter. It looks close to setup to take power from the lower right output connector. Adding a few parts may switch it back to that mode. -- 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] lawnmower robots may be the end of VLF timekeeping
I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html -- 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] Important parameters for a GPS/GNSS antenna
Hi At least according to: ftp://geodesy.noaa.gov/pub/abilich/oldPC/Documents/antcal/calibPapers/Schmitz2002.pdf There are others doing the same thing. Bob On May 9, 2015, at 2:37 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: In message fc02a5e8-5396-4474-a307-546e10909...@n1k.org, Bob Camp writes: The “put the antenna up and rotate it to see what happens” experiment has indeed been done. The objective was not correcting the antenna’s issues, but validating that their model of the antenna’s phase center was correct. They were trying to see if anechoic chamber data really gave correct answers in free space. So this could be a realistic way for us to calibrate the phase-center of an antenna ? -- 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
Hi Only going by the pictures, that looks like the remains of a broken SMB connector. Bob On May 8, 2015, at 10:11 PM, M. George m.matthew.geo...@gmail.com wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M -- M. George ___ 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] Important parameters for a GPS/GNSS antenna
Probably about the only accurate way, really. A GPS antenna is light weight enough that it could be mounted to a suitable turntable clamped to the shaft of a stepper motor. The assumed physical center of the antenna could be mounted directly on the axis of rotation. Then you would know accurately the angle of rotation. If you plotted the GPS location relative to the angular rotation, you could then know the offset from the assumed physical center, and the real phase center... -Chuck Harris Poul-Henning Kamp wrote: In message fc02a5e8-5396-4474-a307-546e10909...@n1k.org, Bob Camp writes: The “put the antenna up and rotate it to see what happens” experiment has indeed been done. The objective was not correcting the antenna’s issues, but validating that their model of the antenna’s phase center was correct. They were trying to see if anechoic chamber data really gave correct answers in free space. So this could be a realistic way for us to calibrate the phase-center of an antenna ? ___ 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] Important parameters for a GPS/GNSS antenna
On 5/8/15 11:37 PM, Poul-Henning Kamp wrote: In message fc02a5e8-5396-4474-a307-546e10909...@n1k.org, Bob Camp writes: The “put the antenna up and rotate it to see what happens” experiment has indeed been done. The objective was not correcting the antenna’s issues, but validating that their model of the antenna’s phase center was correct. They were trying to see if anechoic chamber data really gave correct answers in free space. So this could be a realistic way for us to calibrate the phase-center of an antenna ? Yes.. actually, the best way in the long run would be to collect many hours of GPS satellite data (carrier phase) with the antenna in one position. Then rotate the antenna to a new position, collect a bunch more data, repeat, etc. Then, you post process using the known position of the satellite, which gives you a direction of arrival relative to the antenna. You probably don't need so have a real precise position for the antenna: the apparent motion of the phase center as a function of az/el is probably fairly slow. Isn't that how they collected phase center data for all those antennas on the UNAVCO site: http://facility.unavco.org/kb/questions/458/UNAVCO+Resources%3A+GNSS+Antennas one of the reports has this interesting statement: Antenna rotation tests work well to identify inconsistencies in mean phase center offsets. By occupying a short baseline (less than 10 meters) and rotating the antenna orientation 180 degrees it is possible to see changes in the baseline length caused by the antenna phase center. For antennas of the same type, the rotation tests will highlight variations of an individual antenna relative to the pool of antennas. ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
On 5/8/2015 7:11 PM, M. George wrote: I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. Max, I'm not familiar with that version of it but I do have the -hp- version which was called the 58517A. I'm pretty sure you can find details of that on line. Not that you really need it, just looking at the pictures you can see the schematic since it's all on top. To try to answer your actual question that looks much like a broken off SMB or similar connector. It looks to be easy to convert it back to standard form which uses the power from the number 1 Rx connection to power the antenna if you wanted to do that. I could do a picture of mine if that helps. Dan - ac6ao ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
That is supposed to be an SMB connector, that is what I have on mine. You can drop in a 0-ohm so that you can feed it and the antenna from Port 1. It might be a quicker solution for you. Cheers, Magnus On 05/09/2015 02:27 PM, Bob Camp wrote: Hi Only going by the pictures, that looks like the remains of a broken SMB connector. Bob On May 8, 2015, at 10:11 PM, M. George m.matthew.geo...@gmail.com wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M -- M. George ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
Hello to the group I would agree its coax. But also the n connector to the right can take DC in and power the splitter. So if your rcvr puts out 4.5-30V you are in business. I say this from the internal pix you posted of the unit. That was very helpful. Regards Paul WB8TSL On Sat, May 9, 2015 at 3:15 AM, Hal Murray hmur...@megapathdsl.net wrote: m.matthew.geo...@gmail.com said: Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! The white tube looks like insulation from coax. Have you tried taking the connector apart? You might poke around with an ohmmeter. It looks close to setup to take power from the lower right output connector. Adding a few parts may switch it back to that mode. -- 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 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
Well I was nearly right, it's a broken off SMC connector. I looked inside mine and took a picture. Converting to the standard form would be easy enough. Dan ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
On 5/8/2015 9:11 PM, M. George wrote: I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M According to the datasheet it should be a female SMC but that's hard to call in this case. SMC connectors have jacks and plugs, not Jacks and Jills because the contact and housing genders lead to confusion. See the top of the right column of page 3 here: http://www.marubun.co.jp/product/network/base/qgc18e03bzbd-att/GPS_Active_Splitters.pdf I believe they mean a jack, which should look like this: http://www.amphenolrf.com/media/wysiwyg/SMC_4.jpg Yours appears to have been broken off. I don't think I have any repair parts, though I do have some mating connectors. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Acquired a Symmetricom 5817A-05Q / Power connector Question
My bad and sorry I just realized that N connector is the power to the antenna. So the coax is the way to feed it. It can be anything actually coax is just convenient. Also the N connector on the left can be used to power the system if you add a 0 ohm chip and the small bypass caps. Really great pix for anyone that wants to homebrew there own. Regards Paul On Sat, May 9, 2015 at 10:25 AM, paul swed paulsw...@gmail.com wrote: Hello to the group I would agree its coax. But also the n connector to the right can take DC in and power the splitter. So if your rcvr puts out 4.5-30V you are in business. I say this from the internal pix you posted of the unit. That was very helpful. Regards Paul WB8TSL On Sat, May 9, 2015 at 3:15 AM, Hal Murray hmur...@megapathdsl.net wrote: m.matthew.geo...@gmail.com said: Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! The white tube looks like insulation from coax. Have you tried taking the connector apart? You might poke around with an ohmmeter. It looks close to setup to take power from the lower right output connector. Adding a few parts may switch it back to that mode. -- 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 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] lawnmower robots may be the end of VLF timekeeping
On 5/9/15 5:15 AM, Poul-Henning Kamp wrote: I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html Clearly, you need a better nav system for the robot based on precision time of flight measurements from a network of transmitters around the property linked to your hydrogen maser. More practically, what about some sort of canceller.. This is low frequency, so if you put a pickup loop near the wire, you can collect a sample of the transmitted signal, and then adjust the mag and phase to cancel at your timing receiver antenna. I suspect the variation in mag and phase will be quite small over time/temperature/weather/volume occupancy. ___ 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] lawnmower robots may be the end of VLF timekeeping
Hi There are dog collar systems that work the same way as well as low speed data over power line systems. For what ever reason - they really like to create RFI. My guess is that it’s easy to generate a pulse with logic gates than it is to properly filter that pulse. The first question I’d have about the gizmo is: does it really *need* that awful looking square wave? I’d bet that the “antenna” in the lawnmower is a tuned loop of some sort. It probably would be happy with a much less wide band signal. I’ve had good luck with the buried dog fence setups and some pretty basic filtering. Of course this all works ok for your system. You have to be on very good terms with the neighbors to fix the problem from their system …. Bob On May 9, 2015, at 8:15 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html -- 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] lawnmower robots may be the end of VLF timekeeping
Hi, On 05/09/2015 02:15 PM, Poul-Henning Kamp wrote: I spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html As a ham-operator who just got my license and started to listen to what I have outside the door, I have been increasingly aware of the man-made noise (QRM as we say) poluting in my neighborhood. Working to replace my shitty antenna (Shield of a RG-58 as mounted 2,5 m up between a pair of trees) with a proper OCF-dipole, in hope of at least get some good signals in and out. 73 de Magnus SA0MAD ___ 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] lawnmower robots may be the end of VLF timekeeping
The same has been observed by the lightning listeners at blitzortnung.org -- Björn div Originalmeddelande /divdivFrån: Poul-Henning Kamp p...@phk.freebsd.dk /divdivDatum:2015-05-09 14:15 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] lawnmower robots may be the end of VLF timekeeping /divdiv /divI spent some time capturing some data today. The measurements is from my $20 loop-antenna in the attic, which is something like 8 meters up and 10 meters besides the lawn-mower loop: http://phk.freebsd.dk/time/20150509.html -- 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.
[time-nuts] Acquired a Symmetricom 5817A-05Q / Power connector Question
I took delivery of a Symmetricom 5817A with the 05Q DC power option. The 8 port seems to be going a little less than the 4 ports... not sure on the reasoning there... however I picked it up on the usual auction site for ~125.00 shipped. I thought that was reasonable assuming it works. Anyway, I'm not too proud to admit that I'm not familiar with the power connector that apparently comes with the 05Q option. I have a link below to a couple of pictures. Maybe I missed something obvious when poking around on the internet for documentation, but I can't find anything that describes this connector. I assume it is stock? The +DC input pin/wire can be seen just inside the white tube... again, maybe this is obvious to real time-nuts! I'm working on that time-nut thing! You can browse to the pictures here: http://www.nc7j.com/downloads/NG7M/Time-Nuts/5817A-05Q/ Max NG7M -- M. George ___ 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.
