Re: [time-nuts] WTB: GPS Antenna Splitter
Well, may memory was somewhat faulty. The units I have are 3ZN2PD-1910-1. There is a seller on ebay with the same thing: http://www.ebay.com/itm/Mini-Circuits-3ZN2PD-1910-1-RF-Power-Splitter-LUCENT-COMCODE-408781904-/131191412618 If anybody is interested, I'll let mine go for $20 shipped in USA each. -Pete On 2014-10-15 16:43, Dave M wrote: Pete, I see a ZAPD-30 on the miniCircuits web site. Might those be the models that you have? If so, (and assuming that you can find them), how much for a couple? Thanks, Dave M Peter Loron wrote: Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking around. I'll try to get a look in the stash this weekend. -Pete On 2014-10-06 13:01, Dave M wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hello, You could find off the shelves units from www.gpssource.com MS22 or MS24. For standard splitter www.instockwireless.com with the GPS200/201 and GPS400/401 are interesting. Regards Luc -Message d'origine- De : time-nuts [mailto:time-nuts-boun...@febo.com] De la part de Dave M Envoyé : jeudi 16 octobre 2014 01:44 À : Discussion of precise time and frequency measurement Objet : Re: [time-nuts] WTB: GPS Antenna Splitter Pete, I see a ZAPD-30 on the miniCircuits web site. Might those be the models that you have? If so, (and assuming that you can find them), how much for a couple? Thanks, Dave M Peter Loron wrote: Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking around. I'll try to get a look in the stash this weekend. -Pete On 2014-10-06 13:01, Dave M wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking around. I'll try to get a look in the stash this weekend. -Pete On 2014-10-06 13:01, Dave M wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Pete, I see a ZAPD-30 on the miniCircuits web site. Might those be the models that you have? If so, (and assuming that you can find them), how much for a couple? Thanks, Dave M Peter Loron wrote: Dave, I think I have a MiniCircuits ZAPD-3(?) splitter or two kicking around. I'll try to get a look in the stash this weekend. -Pete On 2014-10-06 13:01, Dave M wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Thanks, Tim, I have wondered about the available antenna current from GPSDO units, but haven't been able to find a spec on any of them, or at least, the GPS units that I have. I have an HP Z3801A and a Nortel GPSTM NTBW50AA. Have you (or anyone) any information on typical available antenna current, or alarm conditions for antenna overcurrent? I know the Nortel unit spec says that it can survive a shorted antenna/cable without damage, but no info on alarms or current limits. My guess is that the unit won't see any satellites and will just go into holdover. The Z3801A must have an active antenna connected (no passive antennas allowed), but no specs in the manual on antenna current limits. I guess I could substitute an active load (transistor or FET) for the antenna so I can vary the current drawn, and see what alarms pop up. Thanks for more info, Dave M Tim Shoppa wrote: At the very low end, a F-cable splitter for like Cable TV will likely (*) get the job done. Many of us are already using RG-6 type cable for the GPS antenna run anyway. (*) Some GPS units may get confused if they have active sensing on the antenna preamp current and this goes out of tolerance. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
I haven't been able to find any information on antenna spacing on any of the GPS mfr's or antenna mfr's web sites. Maybe I just don't know the correct search terms. Can anyone point me to a source for that kind of data? There's a LOT of information about GPS, GPSDO and antennas on the web, and I'll admit that I haven't read it all, but there's just not enough time in a day, and my eyes can't stand the strain to read everything. Point me in the right direction and I'll take it from there. Thanks!! Dave M Bob Camp wrote: Hi You might want to check the spacing spec’s on the antennas you have. Some of them have fairly large spacing recommendations (like 10 feet). Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Bob, Thanks for that. My intent was to mount the antennas on yardarms on a mast. Both antennas will be at the same elevation, just separated horizontally by a couple feet (not 10ft). My concern (and I think you answered it) was how far apart could I place the antennas without having to do another survey when I switch them around. As an alternative, I could enter the antenna coordinated manually into each GPS when I switch antennas. That should avoid a new survey each time. Then, the distance between the antennas shouldn't matter. Thanks for the info!! Dave M Bob Camp wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
John, I found a couple Mini-Circuits ZAPD-2 splitters on Ebay for around $22 each, including shipping. There's still more on Ebay right now, connector style and pricing varies. They're passive splitters, but my antennas have 26 and 35 db gain, respectively, and the cable run is relatively short (about 15 ft of RG-223 from each antenna). There should still be adequate signal available at the receivers, even with the passive splitters. Cheers, Dave M John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hi I have not (yet) seen a GPS antenna that is spec’d to be close spaced to another GPS antenna. I would not recommend putting them closer than about 5 feet. If you do, they will interact with each other and you will not be able to get a “antenna A” to “antenna B” comparison. You will always be looking at some combination of A reflected back and forth to B. Close mounting is a common error when setting up things like factory test systems. It does indeed create problems. A *lot* of people are surprised at the spacing requirements on a timing grade antenna. If you want “Time Nuts Grade” accuracy, you need the best 48 to 96 hour survey you can get. If the survey is off, you will see more drift in a day’s cycle than if it’s correct. If they are mounted on a tower, put one 5 meters above the other. Then when you switch antennas, just bump the survey value +/- 5 M as required. Bob On Oct 8, 2014, at 11:40 AM, Dave M dgmin...@mediacombb.net wrote: Bob, Thanks for that. My intent was to mount the antennas on yardarms on a mast. Both antennas will be at the same elevation, just separated horizontally by a couple feet (not 10ft). My concern (and I think you answered it) was how far apart could I place the antennas without having to do another survey when I switch them around. As an alternative, I could enter the antenna coordinated manually into each GPS when I switch antennas. That should avoid a new survey each time. Then, the distance between the antennas shouldn't matter. Thanks for the info!! Dave M Bob Camp wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
e.g. HP58540A will raise the red alarm LED if DC antenna current is less than 5mA [open] or bigger than 50mA [short]. I thought this was in common with Z3801A but I don't see it mentioned in the Z3801A book. Page 15 of M12+ users guide says: The M12+ is capable of detecting the presence of an antenna. The receiver utilizes an antenna sense circuit that can detect under current (open condition), over current (shorted or exceeding maximum receiver limits), or a valid antenna connection. then goes on to note that an external bias-T will make this detection meaningless. It lists the current limits as 15mA [open] and 80mA [short]. Tim N3QE On Wed, Oct 8, 2014 at 11:22 AM, Dave M dgmin...@mediacombb.net wrote: Thanks, Tim, I have wondered about the available antenna current from GPSDO units, but haven't been able to find a spec on any of them, or at least, the GPS units that I have. I have an HP Z3801A and a Nortel GPSTM NTBW50AA. Have you (or anyone) any information on typical available antenna current, or alarm conditions for antenna overcurrent? I know the Nortel unit spec says that it can survive a shorted antenna/cable without damage, but no info on alarms or current limits. My guess is that the unit won't see any satellites and will just go into holdover. The Z3801A must have an active antenna connected (no passive antennas allowed), but no specs in the manual on antenna current limits. I guess I could substitute an active load (transistor or FET) for the antenna so I can vary the current drawn, and see what alarms pop up. Thanks for more info, Dave M Tim Shoppa wrote: At the very low end, a F-cable splitter for like Cable TV will likely (*) get the job done. Many of us are already using RG-6 type cable for the GPS antenna run anyway. (*) Some GPS units may get confused if they have active sensing on the antenna preamp current and this goes out of tolerance. ___ 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] WTB: GPS Antenna Splitter
From a geodetic antenna manufacturer, I got the recomendation to keep 1m separation between antennas. This was for a sub 5cm position application. But no white papers to quote... /Björn div Originalmeddelande /divdivFrån: Dave M dgmin...@mediacombb.net /divdivDatum:2014-10-08 17:40 (GMT+01:00) /divdivTill: Discussion of precise time and frequency measurement time-nuts@febo.com /divdivRubrik: Re: [time-nuts] WTB: GPS Antenna Splitter /divdiv /divBob, Thanks for that. My intent was to mount the antennas on yardarms on a mast. Both antennas will be at the same elevation, just separated horizontally by a couple feet (not 10ft). My concern (and I think you answered it) was how far apart could I place the antennas without having to do another survey when I switch them around. As an alternative, I could enter the antenna coordinated manually into each GPS when I switch antennas. That should avoid a new survey each time. Then, the distance between the antennas shouldn't matter. Thanks for the info!! Dave M Bob Camp wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
On 10/8/2014 9:01 AM, Dave M wrote: John, I found a couple Mini-Circuits ZAPD-2 splitters on Ebay for around $22 each, i I found one at the local swap meet many years ago for $1. I used that for years when I only had two gps receivers and it worked fine. Opening up the top cover you will easily see the circuit. I cut one of the strip lines from the number two port and inserted a 100 pF DC blocking cap, and a 220 Ohm R plus RF choke (several turns of thin wire) to ground. Number one port Rx feeds the antenna and the Rx on Port 2 thinks it has an antenna connected. With a well sited antenna you will not notice the 3 dB loss. Now with an 8 way -hp- splitter ($10 at the swap) I don't need it any more, but the disadvantage is that one is tempted to try to use all those ports :^( 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] WTB: GPS Antenna Splitter
Hi There are antennas out there that draw as much as 100 ma in “normal” operation. The overload threshold on GPSDO’s and GPS modules varies from 20 ma to 200 ma. It seems to depend on exactly what antenna the manufacturer decided to use as a standard. Undercurrent threshold varies from zero (as it there isn’t one) to 20 ma. Again, it seems to depend on what they were targeting when they made the box you are looking at. In some cases different years production of the same box has different limits (or the limits are not very precise). It’s also possible that some of what I’ve seen is defective, since it’s auction site used pulls / salvage. Yes you read that correctly, a 20 ma antenna will be “under current” on some modules and “over current” on others. Bob On Oct 8, 2014, at 11:31 AM, Tim Shoppa tsho...@gmail.com wrote: e.g. HP58540A will raise the red alarm LED if DC antenna current is less than 5mA [open] or bigger than 50mA [short]. I thought this was in common with Z3801A but I don't see it mentioned in the Z3801A book. Page 15 of M12+ users guide says: The M12+ is capable of detecting the presence of an antenna. The receiver utilizes an antenna sense circuit that can detect under current (open condition), over current (shorted or exceeding maximum receiver limits), or a valid antenna connection. then goes on to note that an external bias-T will make this detection meaningless. It lists the current limits as 15mA [open] and 80mA [short]. Tim N3QE On Wed, Oct 8, 2014 at 11:22 AM, Dave M dgmin...@mediacombb.net wrote: Thanks, Tim, I have wondered about the available antenna current from GPSDO units, but haven't been able to find a spec on any of them, or at least, the GPS units that I have. I have an HP Z3801A and a Nortel GPSTM NTBW50AA. Have you (or anyone) any information on typical available antenna current, or alarm conditions for antenna overcurrent? I know the Nortel unit spec says that it can survive a shorted antenna/cable without damage, but no info on alarms or current limits. My guess is that the unit won't see any satellites and will just go into holdover. The Z3801A must have an active antenna connected (no passive antennas allowed), but no specs in the manual on antenna current limits. I guess I could substitute an active load (transistor or FET) for the antenna so I can vary the current drawn, and see what alarms pop up. Thanks for more info, Dave M Tim Shoppa wrote: At the very low end, a F-cable splitter for like Cable TV will likely (*) get the job done. Many of us are already using RG-6 type cable for the GPS antenna run anyway. (*) Some GPS units may get confused if they have active sensing on the antenna preamp current and this goes out of tolerance. ___ 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] WTB: GPS Antenna Splitter
Thanks for that link, Brooke. I might give that a try, just because it's so cheap. I'll need a couple bias tees to get power to the antennas, regardless of which splitter devices that I settle on. Cheers, Dave M Brooke Clarke wrote: Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hi, For those with a junk basket full of generic splitter/combiners and DC-blocks, go ahead and put something together. Note that most receivers wish to have a DC-load of around 200ohm to not raise antenna fault alarms. I have not found a dedicated GPS splitter cheaper than this from Mini-Circuits http://217.34.103.131/pdfs/ZAPD-2DC+.pdf When trolling the online auction sites, GPS Source and GPS Networking splitters are often less pricy than the HP/Agilent/Symmetricom/Microsemi ones. -- Björn Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey question⦠If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6â to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10â spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] WTB: GPS Antenna Splitter
Hi, Regarding DC load, a friend had problems, so my quick fix was a BNC tee with a SMD inductor in series with a load resistor between tip and shell on one of the BNC branches. Fixed the problem so that when the receiver saw the load it also accepted the GPS signal it was already seeing but disqualifying. Cheers, Magnus div Originalmeddelande /divdivFrån: Björn Gabrielsson b...@lysator.liu.se /divdivDatum:07-10-2014 07:43 (GMT-05:00) /divdivTill: Discussion of precise time and frequency measurement time-nuts@febo.com /divdivRubrik: Re: [time-nuts] WTB: GPS Antenna Splitter /divdiv /divHi, For those with a junk basket full of generic splitter/combiners and DC-blocks, go ahead and put something together. Note that most receivers wish to have a DC-load of around 200ohm to not raise antenna fault alarms. I have not found a dedicated GPS splitter cheaper than this from Mini-Circuits http://217.34.103.131/pdfs/ZAPD-2DC+.pdf When trolling the online auction sites, GPS Source and GPS Networking splitters are often less pricy than the HP/Agilent/Symmetricom/Microsemi ones. -- Björn Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey question⦠If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6â to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10â spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] WTB: GPS Antenna Splitter
Björn, Thanks for letting us know - price isn't too bad - gotta love the P/N - ZAP D - makes you wonder if they have a sense of humor. Regards, John W. *Ordering,Pricing Availability Information* http://www.minicircuits.com/MCLStore/ModelPriceDisplay#*Select Country* http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Part NumberData SheetDescriptionConnector TypeBracket OptionTRAvailability 1-4Price Each ($)Click to add to Shopping Cart1-45-910-24=25(+) Symbol indicates this Model is available as RoHS Compliant/Pb Free http://www.minicircuits.com/quality/environmental_introduction.html. ZAPD-2DC+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSBNC --In Stock$ 74.95$ 74.95$ 64.95$ 63.95-ZAPD-2DC-N+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSN--In Stock$ 79.95$ 79.95$ 69.95$ 68.95-ZAPD-2DC-S+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSSMA--In Stock$ 74.95$ 74.95$ 64.95$ 63.95- On Tue, Oct 7, 2014 at 4:43 AM, Björn Gabrielsson b...@lysator.liu.se wrote: Hi, For those with a junk basket full of generic splitter/combiners and DC-blocks, go ahead and put something together. Note that most receivers wish to have a DC-load of around 200ohm to not raise antenna fault alarms. I have not found a dedicated GPS splitter cheaper than this from Mini-Circuits http://217.34.103.131/pdfs/ZAPD-2DC+.pdf When trolling the online auction sites, GPS Source and GPS Networking splitters are often less pricy than the HP/Agilent/Symmetricom/Microsemi ones. -- Björn Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6†to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___
Re: [time-nuts] WTB: GPS Antenna Splitter
John, Note that Mini-Circuits seems to have made lots of other (GPS) splitters for Lucent and others. http://www.ebay.com/itm/Mini-Circuits-3-Way-Power-Splitter-Combiner-ZB3PD1-1575DC1S-/270834416075 -- Björn Björn, Thanks for letting us know - price isn't too bad - gotta love the P/N - ZAP D - makes you wonder if they have a sense of humor. Regards, John W. *Ordering,Pricing Availability Information* http://www.minicircuits.com/MCLStore/ModelPriceDisplay#*Select Country* http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Part NumberData SheetDescriptionConnector TypeBracket OptionTRAvailability 1-4Price Each ($)Click to add to Shopping Cart1-45-910-24=25(+) Symbol indicates this Model is available as RoHS Compliant/Pb Free http://www.minicircuits.com/quality/environmental_introduction.html. ZAPD-2DC+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSBNC --In Stock$ 74.95$ 74.95$ 64.95$ 63.95-ZAPD-2DC-N+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSN--In Stock$ 79.95$ 79.95$ 69.95$ 68.95-ZAPD-2DC-S+ http://www.minicircuits.com/MCLStore/ModelPriceDisplay#Data Sheet http://www.minicircuits.com/pdfs/ZAPD-2DC+.pdfPower Divider, RoHSSMA--In Stock$ 74.95$ 74.95$ 64.95$ 63.95- On Tue, Oct 7, 2014 at 4:43 AM, Björn Gabrielsson b...@lysator.liu.se wrote: Hi, For those with a junk basket full of generic splitter/combiners and DC-blocks, go ahead and put something together. Note that most receivers wish to have a DC-load of around 200ohm to not raise antenna fault alarms. I have not found a dedicated GPS splitter cheaper than this from Mini-Circuits http://217.34.103.131/pdfs/ZAPD-2DC+.pdf When trolling the online auction sites, GPS Source and GPS Networking splitters are often less pricy than the HP/Agilent/Symmetricom/Microsemi ones. -- Björn Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey questionââ¬Â¦ If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6â⬠to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10ââ¬â¢ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions
[time-nuts] WTB: GPS Antenna Splitter
Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Dave, I had a 4-port GPS splitter, but sold it. I got mine from eBay. It was an HP unit and I got it cheap. You need to watch for a good price on eBay. I see two HP 4-way splitters on eBay for $73. Search for GPS distribution. As for the antenna, I use an HP timing antenna. I see some Nokia timing antennas for $25 on eBay. Joe On Oct 6, 2014 2:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] WTB: GPS Antenna Splitter
At the very low end, a F-cable splitter for like Cable TV will likely (*) get the job done. Many of us are already using RG-6 type cable for the GPS antenna run anyway. (*) Some GPS units may get confused if they have active sensing on the antenna preamp current and this goes out of tolerance. On Mon, Oct 6, 2014 at 4:01 PM, Dave M dgmin...@mediacombb.net javascript:_e(%7B%7D,'cvml','dgmin...@mediacombb.net'); wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com javascript:_e(%7B%7D,'cvml','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] WTB: GPS Antenna Splitter
Hi You might want to check the spacing spec’s on the antennas you have. Some of them have fairly large spacing recommendations (like 10 feet). Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Le 7 oct. 2014 à 03:09, Bob Camp a écrit : Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I use micro-circuits power splitters, ZN4PD1-50-S+, to which I add DC blocking and load to all but one output which is used to power the antennas. Attenuation is low and port isolation adequate (at least I can detect no performance loss with 4 receivers connected). I have three now in service and haven't paid more than $60 a piece including transport from the US. I have also used 2 port ZN2PD-2000s, no relegated to the spares box. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? I haven't put coax switches in the paths but I do manually switch new receivers between the three different antennae that I have to see how they respond. I can detect, via the signal strength bars in the various GPS utilities, that there are differences in antenna performance, and receiver sensitivity, but have not seen any significant survey position differences from spec, though I only have patch antennae. I have done ADEV measurements and don't see any significant difference between different antenna sources. Before today I have not done any investigation on the effect of different antennae on PPS phase. So I am just eyeballing that of a ublox 6M as I type this. With all 3 antennae I do not see more than a few nano seconds phase offset using the same receiver . I am using a T-Bolt PPS to trigger the scope. However, the PPS does does slew around in time, maybe due to the relatively poor sky view that I have, or T-Bolt PPS issue. I have two receivers on the scope ( a Trimble SMT is the other which has been kept on the same antenna during the test) and both are showing the same issue. For a time-nut this looks like a useful field of investigation. Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? I have never seen any survey restart on antenna disconnect/reconnect . No effect on the T-Bolt, or Z3801A and I think that this only occurs on request or on power up depending on available date or receiver design. Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: GPS Antenna Splitter
Hi: This works great and has minimal cost. http://www.prc68.com/I/4GPS.shtml Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html John C. Westmoreland, P.E. wrote: Dave, Can you please let us know what you go with for your splitter choice? I noticed companies like EndRun Technologies use ones from these folks: http://gpsnetworking.com/GPS-antenna-splitters.asp TESSCO might stock those if you ask them. Regards, John W. On Mon, Oct 6, 2014 at 6:09 PM, Bob Camp kb...@n1k.org wrote: Hi Missed the survey question… If a ns in free air is about 1 foot (30 cm), then you probably want a survey that is better than 6” to keep the error down. You do not want to have the antennas on top of each other, so yes, the GPS will need a survey / location each time you change antennas. If you go with the 10’ spacing, then you will get some pretty big jumps without switching the location. Bob On Oct 6, 2014, at 4:01 PM, Dave M dgmin...@mediacombb.net wrote: Does anyone in the group have, or can point me to, a low-cost (but not cheap) 2-port splitter for a GPS antenna? Those on Ebay are rather expensive. I have two GPSDO units, and have both an older timing antenna and a new choke ring antenna (Thanks, Pete L). I already have one 2-port splitter (working well), but my intent is to connect both antennas through the splitters and a couple coaxial relays so that I can, with the twist of a switch, allow me to run each GPS from a different antenna, or both from the same antenna. I would like to gather some data as to the differences between the two antennas. I know I could switch the connections manually, but I like the idea of a switch to sort of automate the connections, and I'd need another splitter anyway. Before I go to the trouble and expense of building upon this idea, are there any comments as to the value of the project? Some questions come to mind: I'm thinking about mounting both antennas on the same mast, at the same elevation, just separated by a couple feet. Any problems that I should be aware of by putting both antennas so close together? Will that small distance have a noticeable effect when switching a receiver from one antenna to the other? Will the GPS notice the difference and want to do another survey? Thanks for your comments. Dave M ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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.
