Re: [time-nuts] 60Hz More or Less
Hi Ed, Have a look in The Art of Electronics by Horrowitz Hill (if you don't hav a copy, you should! or try the local libary). It has a nice circuit for this (Actually a telescope drive IIRC) type of application. Robert G8RPI. From: Ed Mersich wa6...@comcast.net To: time-nuts@febo.com Sent: Sunday, 1 April 2012, 23:18 Subject: [time-nuts] 60Hz More or Less My Heathkit, and other AC clocks have been broken for months now. I started a project to figure out how bad it was. It's getting interesting as I am approaching my goal of coding a software emulation of an AC line clock. During the process I developed a couple of web pages to help me understand the problem better. Frequency meter: http://wa6rzw.homelinux.net/addon/grid/gauge/hertz.html Grid history graph: http://wa6rzw.homelinux.net/addon/grid/graph/wgraph_1.html The meter requires a real HTML5 browser, anything but MSIE. When I started this my goal was to provide an external reference source to the Heathkit CG-1005, so that it will keep correct time. Since I began I have considered a number of hardware solutions to correct or modify the Heathkit. I think I am dragging my feet because there are no replacement clock chips (in case of disaster,) to be found for this model. At the moment I am thinking about modifying a DC-AC inverter and syncing it to an audio oscillator, (don't laugh, my Heathkit 30 year old audio generator is way better, more stable, than the grid). 73, Ed - WA6RZW ___ time-nuts mailing 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] 60Hz More or Less
robert8...@yahoo.co.uk said: Have a look in The Art of Electronics by Horrowitz Hill (if you don't hav a copy, you should! or try the local libary). It has a nice circuit for this (Actually a telescope drive IIRC) type of application. Rats. I can't find my copy. I think the trick is that it needs to drive it at sidereal time so it's off a bit from 60 Hz. I forget what they start with. What do serious (optical) telescopes use for a time base? What did Hubble use? What did they use for the Palomar Sky Survey? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 1 pps correction
OK, thank you. I'll collect the documentation you suggest to study it. Yes, the PRS10 manual available online has no schematic. The paper one does have. Does this means that Stanford Research want it not to be disseminated? On Mon, Apr 2, 2012 at 5:06 AM, Said Jackson saidj...@aol.com wrote: Hi Azelio, its a dual slope interpolator, much like the HP 5334A counter. In fact the 5334A service manual is very nice to go through to get lectured on how this works. The capture hardware is similar to the Linear Tech app note written by Jim Williams (mentioned in the time nuts archives). Basically its a very fast constant current source, and a high quality capacitor. Except Jim charges the cap, then uses an analog to digital converter to capture the time difference. We use a micro controller to capture the time difference on the cap, then capture how long it takes to discharge the cap with about ~1000x slower current than the charge current. Hence we get ~1000x to 1 time dilution, which means the underlying 16.66ns counter resolution becomes a ~16.7ps resolution. While I have never seen the PRS-10 Rubidium schematics (anyone have them in PDF format?) I gather from the description in the service manual that they do something similar to this. The Wavecrest DTS user manuals floating around on the internet also explain how this works. So in short, all that is required to build a unit like this is a bunch of fast analog charge hardware, and an analog comparator that can trigger a counter capture event, and some software for calibration and control... bye, Said Sent from my iPad On Apr 1, 2012, at 4:07, Azelio Boriani azelio.bori...@screen.it wrote: Said, how complex is your 20pS time interval counter? Is it analog, FPGA, something else (if you can disclose some info, of course)? On Sat, Mar 31, 2012 at 11:44 PM, Hal Murray hmur...@megapathdsl.net wrote: mar...@ptsyst.com said: I’ve seen that the peak to peak jitter is reduced from something like 27 ns to 10 ns. Is this a reduction of just the jitter, or is the actual accuracy to UTC also improved by this amount. Have you read the hanging-bridges paper? Tom Clark and Rick Hambly: Timing for VLBI http://gpstime.com/files/tow-time2009.pdf I think that is the key to understanding this area. If you could average over many sawtooth cycles, you should get an accurate answer. The problem is that you don't get to pick how many cycles fit into your averaging time. The sawtooth pattern is the beat between two frequencies. One of them is drifting with time/temperature. If you are unlucky, the beat frequency can be very very low. The sawtooth correction lets you correct on a cycle-by-cycle basis. You don't need to average over many samples. -- These are my opinions, not necessarily my employer's. 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. ___ time-nuts mailing 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] Opera coordinator has resigned
On 2 April 2012 00:54, Jim Lux jim...@earthlink.net wrote: On 4/1/12 2:25 PM, Dr. David Kirkby wrote: So it tells us nothing very much about the life of them in normal use, with a human mating and demating them. - or even the repeatability of the reflection coefficient with a human in the equation. Not a whole lot, but the whole paper goes into the various factors involved. Ultimately, it winds up that the mismatch from SMAs is a) a whole lot less than the usual worst case spec of 1.05:1 or 1.03:1 (which is basically a measurement limit) and b) doesn't change much with many mate/demate cycles He did look at things like coupling nut friction and what not. Without seeing the paper, it's difficult to comment much more. Clearly if he had shown the performance to be worst than the spec, then I think he would have a useful result, as he would have put a limit on what was achieveable even with perfect use. But I think the human element is quite critical with SMA connectors - or pretty much any connector for that matter. Anyway, SMAs are pretty good connectors overall for most RF things. It's a long time since I have used any LEMO connectors - the subject of orginal discussion. I've not been following the orignal thread in detail, or looked at the relevant papers, but I do feel it odd and unjust that someone should resign over what was a genuine mistake. We all make them from time to time, and sometimes the consequencies are quite serious - like someone dies. dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 1 pps correction
The PRS10 schematics are available on line from Didier. See the following link: http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/SRS Sincerely, Stijn Op 02-04-12 09:48, Azelio Boriani schreef: OK, thank you. I'll collect the documentation you suggest to study it. Yes, the PRS10 manual available online has no schematic. The paper one does have. Does this means that Stanford Research want it not to be disseminated? On Mon, Apr 2, 2012 at 5:06 AM, Said Jacksonsaidj...@aol.com wrote: Hi Azelio, its a dual slope interpolator, much like the HP 5334A counter. In fact the 5334A service manual is very nice to go through to get lectured on how this works. The capture hardware is similar to the Linear Tech app note written by Jim Williams (mentioned in the time nuts archives). Basically its a very fast constant current source, and a high quality capacitor. Except Jim charges the cap, then uses an analog to digital converter to capture the time difference. We use a micro controller to capture the time difference on the cap, then capture how long it takes to discharge the cap with about ~1000x slower current than the charge current. Hence we get ~1000x to 1 time dilution, which means the underlying 16.66ns counter resolution becomes a ~16.7ps resolution. While I have never seen the PRS-10 Rubidium schematics (anyone have them in PDF format?) I gather from the description in the service manual that they do something similar to this. The Wavecrest DTS user manuals floating around on the internet also explain how this works. So in short, all that is required to build a unit like this is a bunch of fast analog charge hardware, and an analog comparator that can trigger a counter capture event, and some software for calibration and control... bye, Said Sent from my iPad On Apr 1, 2012, at 4:07, Azelio Borianiazelio.bori...@screen.it wrote: Said, how complex is your 20pS time interval counter? Is it analog, FPGA, something else (if you can disclose some info, of course)? On Sat, Mar 31, 2012 at 11:44 PM, Hal Murrayhmur...@megapathdsl.net wrote: mar...@ptsyst.com said: I’ve seen that the peak to peak jitter is reduced from something like 27 ns to 10 ns. Is this a reduction of just the jitter, or is the actual accuracy to UTC also improved by this amount. Have you read the hanging-bridges paper? Tom Clark and Rick Hambly: Timing for VLBI http://gpstime.com/files/tow-time2009.pdf I think that is the key to understanding this area. If you could average over many sawtooth cycles, you should get an accurate answer. The problem is that you don't get to pick how many cycles fit into your averaging time. The sawtooth pattern is the beat between two frequencies. One of them is drifting with time/temperature. If you are unlucky, the beat frequency can be very very low. The sawtooth correction lets you correct on a cycle-by-cycle basis. You don't need to average over many samples. -- These are my opinions, not necessarily my employer's. 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. ___ time-nuts mailing 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] 1 pps correction
Oh, well, I have the original PRS10 manual as we (that is, the company) bought a new PRS10 one month ago. I was enquiring wether or not it can be scanned and sent to you. Now it no longer matters. On Mon, Apr 2, 2012 at 11:35 AM, Stijn Nestra st...@pe1rks.nl wrote: The PRS10 schematics are available on line from Didier. See the following link: http://www.ko4bb.com/manuals/**index.php?dir=05%29_GPS_**Timing/SRShttp://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/SRS Sincerely, Stijn Op 02-04-12 09:48, Azelio Boriani schreef: OK, thank you. I'll collect the documentation you suggest to study it. Yes, the PRS10 manual available online has no schematic. The paper one does have. Does this means that Stanford Research want it not to be disseminated? On Mon, Apr 2, 2012 at 5:06 AM, Said Jacksonsaidj...@aol.com wrote: Hi Azelio, its a dual slope interpolator, much like the HP 5334A counter. In fact the 5334A service manual is very nice to go through to get lectured on how this works. The capture hardware is similar to the Linear Tech app note written by Jim Williams (mentioned in the time nuts archives). Basically its a very fast constant current source, and a high quality capacitor. Except Jim charges the cap, then uses an analog to digital converter to capture the time difference. We use a micro controller to capture the time difference on the cap, then capture how long it takes to discharge the cap with about ~1000x slower current than the charge current. Hence we get ~1000x to 1 time dilution, which means the underlying 16.66ns counter resolution becomes a ~16.7ps resolution. While I have never seen the PRS-10 Rubidium schematics (anyone have them in PDF format?) I gather from the description in the service manual that they do something similar to this. The Wavecrest DTS user manuals floating around on the internet also explain how this works. So in short, all that is required to build a unit like this is a bunch of fast analog charge hardware, and an analog comparator that can trigger a counter capture event, and some software for calibration and control... bye, Said Sent from my iPad On Apr 1, 2012, at 4:07, Azelio Borianiazelio.boriani@screen.**itazelio.bori...@screen.it wrote: Said, how complex is your 20pS time interval counter? Is it analog, FPGA, something else (if you can disclose some info, of course)? On Sat, Mar 31, 2012 at 11:44 PM, Hal Murrayhmur...@megapathdsl.net wrote: mar...@ptsyst.com said: I’ve seen that the peak to peak jitter is reduced from something like 27 ns to 10 ns. Is this a reduction of just the jitter, or is the actual accuracy to UTC also improved by this amount. Have you read the hanging-bridges paper? Tom Clark and Rick Hambly: Timing for VLBI http://gpstime.com/files/tow-**time2009.pdfhttp://gpstime.com/files/tow-time2009.pdf I think that is the key to understanding this area. If you could average over many sawtooth cycles, you should get an accurate answer. The problem is that you don't get to pick how many cycles fit into your averaging time. The sawtooth pattern is the beat between two frequencies. One of them is drifting with time/temperature. If you are unlucky, the beat frequency can be very very low. The sawtooth correction lets you correct on a cycle-by-cycle basis. You don't need to average over many samples. -- These are my opinions, not necessarily my employer's. I hate spam. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/**mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] 60Hz More or Less
On 4/2/12 12:19 AM, Hal Murray wrote: robert8...@yahoo.co.uk said: Have a look in The Art of Electronics by Horrowitz Hill (if you don't hav a copy, you should! or try the local libary). It has a nice circuit for this (Actually a telescope drive IIRC) type of application. Rats. I can't find my copy. I think the trick is that it needs to drive it at sidereal time so it's off a bit from 60 Hz. I forget what they start with. What do serious (optical) telescopes use for a time base? What did Hubble use? What did they use for the Palomar Sky Survey? These days.. a quartz oscillator, and/or, a closed loop control based on tracking a guide star. What did Hubble use up on Mt. Wilson? A mechanical clock One final accessory remained to be built, the clock drive that would regulate the speed at which the telescope would sweep across the sky, tracing the arcs followed by the stars during the night. The telescope is like a giant grandfather clock, with the tube moved by the force of a falling weight. The clock drive mechanism keeps that rate constant and allows for minor adjustments. However, this clock had to be considerably more massive than any timepiece. A 2- ton falling weight drives the machine, while over 1,000 pounds of bronze parts were cast for the mechanism, and almost 3,000 pounds of iron. The force is then transmitted to the drive gear on the polar axis of the telescope, a precision gear like that of a fine Swiss watch, but 17 feet across! http://www.mtwilson.edu/Simmons4.php I think it has been updated to some sort of servo scheme based on a clock that runs on sidereal time. A friend was up there about 10 years ago for something and mentioned that a lot of the original drive electronics is still in use. Carbon fiber filaments were mentioned. John Strong's book on making stuff (procedures in experimental physics) probably has a lot of the details (like how they put the reflective coating on the mirror). That book is a fascinating look at state of the art in the early part of the 20th century (you want to make your own Geiger-Muller tubes... it's in there). Every physics/lab tinkerer should have a copy (it's cheap in paperback from Lindsay books (http://www.lindsaybks.com/... don't know if they still have it), or probably Amazon, too)(just checked amazon.. $35 for used??? what are they thinking) ___ time-nuts mailing 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] Opera coordinator has resigned
If the FTL neutrino discovery had been kept quiet until fully vetted, he probably would not have had to resign. Compare with the discovery of Cold Fusion. The desire for PR got ahead of the science. In my view, somebody who is in responsible charge of any project that size morally ought to be held accountable as The buck stops here. Frankly, I'm entirely fed up with those in charge of projects who walk away scott free after a giant disaster. Those in responsible charge should be held liable, both professionally and personally, IMO. YMMV, -John [snip] I've not been following the orignal thread in detail, or looked at the relevant papers, but I do feel it odd and unjust that someone should resign over what was a genuine mistake. We all make them from time to time, and sometimes the consequencies are quite serious - like someone dies. dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LEA-6T Group buy
Hi, Note that there should soon be a LEA6T eval board available from sysmocom http://laforge.gnumonks.org/weblog/2012/03/16/#20120316-osmo_lea6t_gps_timing Estimated price is 90 EUR excl VAT in the EU. Cheers, Sylvain ___ time-nuts mailing 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] LEA6-T Group Buy
Note that there should soon be a LEA6T eval board available from sysmocom http://laforge.gnumonks.org/weblog/2012/03/16/#20120316-osmo_lea6t_gps_timing Estimated price is 90 EUR excl VAT in the EU. Anyone know if these will have the RAW output for use with RTKLib? Also assume can program for 10 MHz out? Had the door slammed in my face when trying to buy an eval board for the 6-T from the mfgr. N0UU ___ time-nuts mailing 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] LEA6-T Group Buy
I see that the board has the serial port and the USB, so you have the complete I/O suite available. On Mon, Apr 2, 2012 at 10:11 PM, lstosk...@cox.net wrote: Note that there should soon be a LEA6T eval board available from sysmocom http://laforge.gnumonks.org/weblog/2012/03/16/#20120316-osmo_lea6t_gps_timing Estimated price is 90 EUR excl VAT in the EU. Anyone know if these will have the RAW output for use with RTKLib? Also assume can program for 10 MHz out? Had the door slammed in my face when trying to buy an eval board for the 6-T from the mfgr. N0UU ___ time-nuts mailing 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] LEA6-T Group Buy
On 2 Apr, 2012, at 13:11 , lstosk...@cox.net lstosk...@cox.net wrote: Note that there should soon be a LEA6T eval board available from sysmocom http://laforge.gnumonks.org/weblog/2012/03/16/#20120316-osmo_lea6t_gps_timing Estimated price is 90 EUR excl VAT in the EU. Anyone know if these will have the RAW output for use with RTKLib? Also assume can program for 10 MHz out? Had the door slammed in my face when trying to buy an eval board for the 6-T from the mfgr. ?? I bought an EVK-6T from the manufacturer a little while ago without trouble. The only thing associated with the transaction that I wasn't perfectly happy with was the price. I should say, though, that the manufacturer's eval kit puts the board in a rather nice case, with the two programmable pulse outputs only being available on the DE-9 RS232 connector, at RS232 voltage levels. Not only are RS232 voltages inconvenient for many purposes, but the MAX3232 converter they used adds 100 ns of delay. The high speed versions of the signals are available on the board, but you need to take the board out of the case to use them and they use those teeny, tiny MMCX connectors. Given a choice I'd rather have a board without paying for a case I have to throw away, with better connectors for the timing signals. I think this is a very good 50 channel GPS receiver, though, and the manufacturer's board isn't bad if you want to play with it from a computer since both PPS outputs and the Extint input are conveniently tied to RS232 control pins. Dennis Ferguson ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Antenna for t-bolt
Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
I found these at a local surplus shop. $15 each. It worked on the Starloc. I got the 240 version which has high gain. The Starloc is a bit deaf. So to pick an antenna for the Tbolt, it should meet gain requirements and voltage. Marine grade is kind of overkill. Potentially the marine grade gear is not as good as the dedicated timing GPS antennas since those (I believe) are designed not to view the horizon as well as a standard GPS antenna. http://www.hankookantennausa.com/products/gps/gps_019.htm ___ time-nuts mailing 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] Efratom M3100
On 04/02/2012 02:33 AM, ewkeh...@aol.com wrote: Magnus I am systematically checking every thing. Power is every where, get a very strong 60 MHz with the 5.3125 clearly visible on the spectrum analyzer also counted both with a counter, checked the 85 Hz modulation on the tuning diode, is a small signal but the same on my working M 100. Some is off the M 100 some off the FRS. Working on the Servo assembly. Because of dense packaging it is very difficult to find the output signal, but I am now sitting down with the ohm meter and retracing all the interconnects on the servo board. It is multi layer. Once I have the 85/170 pass I will inject a variable frequency, maybe 85 Hz is wrong. I will keep you posted. The biggest problem is the packing density, very hard to get to the pins of the IC's. Lot's of test-points. The 4060 (U3) is hooked up as RC oscillator based. 4053 (U2) demodulates. Isn't the large 1 uF cap the integrator cap? TP10, TP11, TP13 and TP15 looks like suspects. TP17, TP5, TP14 and TP9 looks like coming out of modulation counter, but the last seems to come from the analog frontend at the bottom part. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
The booster amps used for satellite dishes work on GPS as well. I used one when I was feeding two Thunderbolts thru a splitter. On 04/02/2012 03:28 PM, Bob Martin wrote: Bill-- The Thunderbolt wants a higher gain antenna than most standard GPS receivers. I tried standard Garmin active antennas, and while they worked (I have a good view of the sky), signal levels could be better. Best match probably is something like the HP/Symmetricom 58532A antenna, which has gain 30dB -- most active GPS antennas are in the 24 - 26 dB range. They're not cheap, but they'll do the job. If you have much distance to cover, feed line is of course important as well -- 9913, LMR 400, good quality RG6, something with low loss at 1.5 GHz. I'm using a 58532A feeding a Symmetricom 58535A active GPS splitter to run a Thunderbolt and a Datum Tymserve 2100. Feedline is 9913 to the splitter, and short LMR 195 SMA cables from there. (Yes you can find F to SMA adapters, on eBay, even though many will shudder at the concept...) 73 Bob K6RTM On Apr 2, 2012, at 15:01, time-nuts-requ...@febo.com wrote: -- Message: 4 Date: Mon, 2 Apr 2012 17:39:40 -0400 From: Bill Richesbill.ric...@verizon.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: [time-nuts] Antenna for t-bolt Message-ID:01ac01cd1119$1c699af0$553cd0d0$@ric...@verizon.net Content-Type: text/plain; charset=US-ASCII Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com Developer of Industrial ZMODEM(Tm) for Embedded Applications Omen Technology Inc The High Reliability Software 10255 NW Old Cornelius Pass Portland OR 97231 503-614-0430 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
Here is the antenna I purchased from Ebay (China). This is a Lucent 40dB timing antenna that should work for any GPS receiver. Mine took about 2 weeks to get here and there were no problems getting it. This unit is currently available for 'buy it now at $28 dollars. http://www.ebay.com/itm/lucent-GPS-Timing-Reference-Antenna-antenne-40db-N-/230771298518?pt=LH_DefaultDomain_0hash=item35bb0a90d6 Jerry Mulchin At 03:28 PM 4/2/2012, you wrote: Bill-- The Thunderbolt wants a higher gain antenna than most standard GPS receivers. I tried standard Garmin active antennas, and while they worked (I have a good view of the sky), signal levels could be better. Best match probably is something like the HP/Symmetricom 58532A antenna, which has gain 30dB -- most active GPS antennas are in the 24 - 26 dB range. They're not cheap, but they'll do the job. If you have much distance to cover, feed line is of course important as well -- 9913, LMR 400, good quality RG6, something with low loss at 1.5 GHz. I'm using a 58532A feeding a Symmetricom 58535A active GPS splitter to run a Thunderbolt and a Datum Tymserve 2100. Feedline is 9913 to the splitter, and short LMR 195 SMA cables from there. (Yes you can find F to SMA adapters, on eBay, even though many will shudder at the concept...) 73 Bob K6RTM On Apr 2, 2012, at 15:01, time-nuts-requ...@febo.com wrote: -- Message: 4 Date: Mon, 2 Apr 2012 17:39:40 -0400 From: Bill Riches bill.ric...@verizon.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: [time-nuts] Antenna for t-bolt Message-ID: 01ac01cd1119$1c699af0$553cd0d0$@ric...@verizon.net Content-Type: text/plain; charset=US-ASCII Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Jerry Mulchin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
On Mon, Apr 2, 2012 at 3:28 PM, Bob Martin k6...@comcast.net wrote: Bill-- The Thunderbolt wants a higher gain antenna than most standard GPS receivers. I tried standard Garmin active antennas, and while they worked (I have a good view of the sky), signal levels could be better. Best match probably is something like the HP/Symmetricom 58532A antenna, which has gain 30dB -- most active GPS antennas are in the 24 - 26 dB range. I have a 26dB timing antenna the kind that is easy to find on eBay. It works well with my T-bolt. I have the antenna on a short mast made of galvanized iron plumbing pipe with the feed line coming down the center of the iron pipe. Yes it is true the t-bolt can use more gain but it is not so clear I'd get better timing. I can lock satellites from horizon to horizon. I think what IS clear is that location maters MUCH more than any other factor. First you need to find a way for the antenna to get a full 360 degree view of the sky down to the horizon, all the way around. This may mean you have to move the t-bolt too. By that I mean, rather then saying you can't run antenna feed down from the roof, place the t-bolt new the roof then use cat-5 wire ro whatever to bring the 10MHZ and PPS and Serial data down. Details are site dependent but getting the antenna to a good location should drive all yu other trade offs. Lastly you can replace the antenna with a real timing antenna. I had a patch type mag mount on the roof, it worked but the pointed radome but keeps birds off and if it snowed here would keep that off too. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
All gone .. I got one. I'm happy for $26 but the thing was pretty badly treated in its life and the seal did not look well. If yours is as knocked around I'd suggest pulling it apart and use a bit of sealer (RTV etc) Now to come up with a mount, they are more rare and usually go for more then the antennas -pete On Mon, Apr 2, 2012 at 4:00 PM, Jerry Mulchin jmulc...@cox.net wrote: Here is the antenna I purchased from Ebay (China). This is a Lucent 40dB timing antenna that should work for any GPS receiver. Mine took about 2 weeks to get here and there were no problems getting it. This unit is currently available for 'buy it now at $28 dollars. http://www.ebay.com/itm/lucent-GPS-Timing-Reference-Antenna-antenne-40db-N-/230771298518?pt=LH_DefaultDomain_0hash=item35bb0a90d6 Jerry Mulchin At 03:28 PM 4/2/2012, you wrote: Bill-- The Thunderbolt wants a higher gain antenna than most standard GPS receivers. I tried standard Garmin active antennas, and while they worked (I have a good view of the sky), signal levels could be better. Best match probably is something like the HP/Symmetricom 58532A antenna, which has gain 30dB -- most active GPS antennas are in the 24 - 26 dB range. They're not cheap, but they'll do the job. If you have much distance to cover, feed line is of course important as well -- 9913, LMR 400, good quality RG6, something with low loss at 1.5 GHz. I'm using a 58532A feeding a Symmetricom 58535A active GPS splitter to run a Thunderbolt and a Datum Tymserve 2100. Feedline is 9913 to the splitter, and short LMR 195 SMA cables from there. (Yes you can find F to SMA adapters, on eBay, even though many will shudder at the concept...) 73 Bob K6RTM On Apr 2, 2012, at 15:01, time-nuts-requ...@febo.com wrote: -- Message: 4 Date: Mon, 2 Apr 2012 17:39:40 -0400 From: Bill Riches bill.ric...@verizon.net To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Subject: [time-nuts] Antenna for t-bolt Message-ID: 01ac01cd1119$1c699af0$553cd0d0$@ric...@verizon.net Content-Type: text/plain; charset=US-ASCII Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. Jerry Mulchin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
On Mon, Apr 2, 2012 at 4:00 PM, Jerry Mulchin jmulc...@cox.net wrote: Here is the antenna I purchased from Ebay (China). This is a Lucent 40dB timing antenna that should work for any GPS receiver. Mine took about 2 weeks to get here and there were no problems getting it. This unit is currently available for 'buy it now at $28 dollars. Yours is technically better. But mine is eBay #270881742870 and works perfectly. I'm using about 25 feet of rg58 cable and might swap it out for rg8 just because I have a bunch of it. I keep the t-bolt on a shelf in a second floor walk-in closet that has no exterior walls and no forced air heater vent so it stays very stabile temperature. The attic got to hot and to cold, other places had heating vents and would cycle. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
There are still some listed at GBP 19.00. Search for lucent 40db. Orin. On Mon, Apr 2, 2012 at 4:14 PM, Pete Lancashire p...@petelancashire.comwrote: All gone .. I got one. I'm happy for $26 but the thing was pretty badly treated in its life and the seal did not look well. If yours is as knocked around I'd suggest pulling it apart and use a bit of sealer (RTV etc) ___ time-nuts mailing 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] Fail on HP5065A PSU repair
Magnus, is that the same little transformer that I sent you a while back? If so, did you add the PTC current limiter that I included? That should have saved it from failure of the driver transistors. I think there's a problem with that circuit, so I don't think you should take a chance on any more transformers without thoroughly checking the rest of the parts. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 1 pps correction
On 04/02/2012 11:35 AM, Stijn Nestra wrote: The PRS10 schematics are available on line from Didier. See the following link: http://www.ko4bb.com/manuals/index.php?dir=05%29_GPS_Timing/SRS Thanks! On the same page (21/24) as the x2000 PPS time interpolator is also the PPS programmable delay circuit. Not too complex. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for T-bolt
There's a lot of five Racal survey antennae on eBay, lot 370600485855 which have been round at least once before. I use one of these with a T'bolt and it performs extremely well; I'm not sure what one would do with the other four however... 5 Volt operation, TNC connector, c. 30 dB gain. 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] Efratom M3100
Magnus RC oscillator and demodulator along with the 1 uF and integrator are all standard Efratom, use different pins and the oscillator is 2.72 KHz the problem is the signal path from the detector to the demodulator. That is what I am looking for. Will get there. will take time. Thanks again Bert In a message dated 4/2/2012 6:29:19 P.M. Eastern Daylight Time, mag...@rubidium.dyndns.org writes: On 04/02/2012 02:33 AM, ewkeh...@aol.com wrote: Magnus I am systematically checking every thing. Power is every where, get a very strong 60 MHz with the 5.3125 clearly visible on the spectrum analyzer also counted both with a counter, checked the 85 Hz modulation on the tuning diode, is a small signal but the same on my working M 100. Some is off the M 100 some off the FRS. Working on the Servo assembly. Because of dense packaging it is very difficult to find the output signal, but I am now sitting down with the ohm meter and retracing all the interconnects on the servo board. It is multi layer. Once I have the 85/170 pass I will inject a variable frequency, maybe 85 Hz is wrong. I will keep you posted. The biggest problem is the packing density, very hard to get to the pins of the IC's. Lot's of test-points. The 4060 (U3) is hooked up as RC oscillator based. 4053 (U2) demodulates. Isn't the large 1 uF cap the integrator cap? TP10, TP11, TP13 and TP15 looks like suspects. TP17, TP5, TP14 and TP9 looks like coming out of modulation counter, but the last seems to come from the analog frontend at the bottom part. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] would an optical primary standard provide any general benefit?
Having read this NIST review paper by Thomas E. Parker, The uncertainty in the realization and dissemination of the SI second from a systems point of view http://tf.boulder.nist.gov/general/pdf/2564.pdf ...it seems that any potential improvement in frequency standards (Cs fountain - optical clocks) will not benefit most time/frequency users, because existing long-range time-transfer methods (TWSTFT and GPS carrier phase) are still limited to at best 2E-16 for 30-day averaging, and there is no generally practical way to improve them currently in sight. (Laser ranging of satellites being considered not generally practical). Just curious what people think, is this too pessimistic a view, or is it fair to say that having a 10x improved primary standard would not improve stability or accuracy for anyone outside of stabilized optical-fiber distance from such a standard? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
I have a Symetricom 58532A which I bought on eBay for $50 with shipping. That is probably the best antenna you can get, and it won't break the bank. I also have a Trimble Bullet, the antenna that was designed to go with the Tunderbolt. It is a very good antenna also, but harder to find, and it has lower gain than the 58532A, so at my location (under the roof in Florida), at the end of 50 feet of good quality 75 ohm coax, the Symetricom unit works better. I also have several pucks, including very inexpensive Chinese-made ones and a very nice Trimble mag-mount puck that is the best of all the pucks I have (in terms of performance and also mechanical design) and which I got for $15 on eBay also. They all work, but the Trimble puck is the one I take if I need to go mobile. Most the pucks I have receive better than the Trimble Bullet. They are probably not as good as far as multipath rejection for low angle signals, but they are more sensitive and I see more satellites with them. Didier KO4BB On Mon, Apr 2, 2012 at 4:39 PM, Bill Riches bill.ric...@verizon.net wrote: Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
On 4/2/2012 5:39 PM, Bill Riches wrote: Question is that I am looking for suggestions for GPS antenna for t-bolt. I use an Andrew GPS-QBW-26N (quadrifilar). 26 db amp + 4 db antenna gain, through an HP 58516 distribution amp. Works well for me. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
Hi Didier, I have one of the Trimble Bullet antennas, that was supposed to be from a working system, but it is deaf as a post... really dead. Given that it is supposed to be more than 30db gain, it should do better than any of the hockey puck antennas. I wonder if there is a common failure mode in that antenna? -Chuck Harris Didier Juges wrote: I have a Symetricom 58532A which I bought on eBay for $50 with shipping. That is probably the best antenna you can get, and it won't break the bank. I also have a Trimble Bullet, the antenna that was designed to go with the Tunderbolt. It is a very good antenna also, but harder to find, and it has lower gain than the 58532A, so at my location (under the roof in Florida), at the end of 50 feet of good quality 75 ohm coax, the Symetricom unit works better. I also have several pucks, including very inexpensive Chinese-made ones and a very nice Trimble mag-mount puck that is the best of all the pucks I have (in terms of performance and also mechanical design) and which I got for $15 on eBay also. They all work, but the Trimble puck is the one I take if I need to go mobile. Most the pucks I have receive better than the Trimble Bullet. They are probably not as good as far as multipath rejection for low angle signals, but they are more sensitive and I see more satellites with them. Didier KO4BB On Mon, Apr 2, 2012 at 4:39 PM, Bill Richesbill.ric...@verizon.net wrote: Hi guys, I have asked this question several times over the past few weeks and get no answer. Have I been ostracized??!! Question is that I am looking for suggestions for GPS antenna for t-bolt. The antenna that I am using now is a no name and I not know where it came from! Wonder if a Garman GA-30 will work? 73, Bill, WA2DVU Cape May, NJ ___ time-nuts mailing 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] Efratom M3100
I have some SPTB-100 units, which are similar to M100 units, which may be similar to yours. A few years ago, one failed to lock, regardless of adjustment, and I found that one of the integrator capacitors in the OCXO control loop was very leaky. I don't recall which one, and couldn't even identify it because I had no exact schematic, but I was surprised because it was a plastic or small-valued ceramic unit (and not within the high temperature environment of the oven), which in my experience were usually quite reliable. Ed ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
Here is a picture of the guts of the antenna that was made for the Thunderbolt. They don't appear to have gone to much effort to have a high horizon. -Chuck Harris Chuck Forsberg WA7KGX N2469R wrote: I got a mushroom shaped antenna along with my Thunderbolt. It came with some rg58 terminated in an F connector. I don't know if it is a timing reference antenna or just a plain GPS antenna. Presumably a timing antenna would block low elevation signals to reduce multipath. attachment: Trimble-T-Bolt-Antenna.JPG___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Antenna for t-bolt
c...@omen.com said: Presumably a timing antenna would block low elevation signals to reduce multipath. Maybe, but there is a software aspect to the filter. You get to select the elevation angle. I don't remember seeing any specs about the filtering angles of various antennas. Has anybody seen something like that? -- These are my opinions, not necessarily my employer's. 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.
