Re: [time-nuts] Updated Shera controller
You can't predict the settling time of an opamp from its slew rate or its gain-bandwidth product. The TS272 datasheet has no settling time spec whatsoever. In this case, since there is no spec it needs to be measured. Opamps with 2 or more cascaded gain stages like these are notorious for poor settling times. 10us is merely guesswork. The settling time could well be much longer and it may depend on the input signal level. Bruce Richard H McCorkle wrote: FYI, The TS272/TS274 have a slew rate of 5.5v/us at unity gain, the max voltage on the cap is 2.7v in the new design, and the voltage is read 10us after sample complete, so the buffer should have time to stabilize after the sample before being read. Richard Bruce wrote: Not really its both overkill as it doesnt timestamp, it only measures a time interval and underkill in that theres no DAC. There are also some concerns about the settling time of the TAC buffer opamp which isnt strictly necessary for the lower resolution required in this application. PPS timestamping only needs a single TAC. Bruce ___ 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] Updated Shera controller
Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. Ulrich Bangert -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Poul-Henning Kamp Gesendet: Mittwoch, 28. Juli 2010 22:47 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Updated Shera controller In message 4c5092fa.2030...@xtra.co.nz, Bruce Griffiths writes: Instead of copying the Shera controller albeit with higher resolution its probably more cost effective to choose a microprocessor with built in time stamping capability. Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Updated Shera controller
In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Message for John Allen K1AE re 74AC175PC
Hi John Apologies to you and all for writing via the list but I've had no response to direct emails so not sure if they're being dumped by a spam filter or whatever. You expressed interest in two off 74AC175PC ICs and I would be grateful if you could contact me again please to confirm whether or not you still require them. If not it's no problem but all others requested have now been shipped and I didn't want to offer yours to anyone else without checking with you first. regards Nigel GM8PZR ___ 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] Regarding the option 040...
That was what naturally came to my mind too as all of the scads of HP stuff I have here and use daily is a lot older and 040's were just that, the HP-IB, now GPIB port board. I sent him an email suggesting it might just be the Universal option for the I/O of the system as with my 5328A's they are the only thing that the 040 is something other than the com port. Just food for thought and I hope I have not made things worse for him or am confusing anything. Now I am curious too as the data is not readily had on the net and you posted from a 19 series, his was a 5335A wasn't it??? Warm regards, Douglas M. Wire, GED, FNA, PUPCo Studios PUPCo Research Group mailto:cont...@pupcostudios.com cont...@pupcostudios.com Description: PUPCo_outlook_2010_sig_1 image003.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.
[time-nuts] DELET POST MISREAD YOUR DATA!
1993 catalog. Doh. Wish I could recall that and now I have polluted the list! Sorry everyone. Warm regards, Douglas M. Wire, GED, FNA, PUPCo Studios PUPCo Research Group mailto:cont...@pupcostudios.com cont...@pupcostudios.com Description: PUPCo_outlook_2010_sig_1 image003.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.
[time-nuts] Error correction and test G
Even worse for some reason the list got my errant thinking backward, the HP-IP/GBIP port and MB are correct! (Re-posting for error correction and in plain-text as I have no idea why the board picked up that giant string in the domain's email address, for future reference...) Warm regards, Douglas M. Wire, GED, FNA, PUPCo Studios PUPCo Research Group cont...@pupcostudios.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Updated Shera controller
Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? -- Poul-Henning Kamp| UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Updated Shera controller
I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Updated Shera controller
Hello, El 29/07/2010 07:48, Hal Murray escribió: I'm not familiar with windows. I think PIC and AVR come with free software for windows which works well with their low cost development platforms. The compiler may be crippled to get you to buy the real version from somebody, but I'm pretty sure it's good enough to get well off the ground. I'm not familiar with what's available from the vendors for ARM. gcc has good support for PIC, AVR, and ARM. There may be better, but it's well past good enough. (It runs on windows if you use cygwin.) Atmel provides free of charge a nice windows tool for the AVR, http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725 This integrates the GCC compiler and a quite nice development environment (it has been a while since last time I used it), and it is not a crippled commercial tool version. There is also no need to run cygwin to use this tool. For the PIC I'm not aware of anything similar. I used time ago the IAR tools, but they are both really expensive and really not so good. Anyway, I don't like PICs For ARM there is also windows-based GCC tools set, that can be integrated in Eclipse environment. You can get it at http://www.yagarto.de . I find ARM7 derivatives (AT91SAM7X or AT91SAM7S from Atmel, but there are a lot from several manufacturers) very nice, fast and unexpensive 32-bit microcontrollers, adequate for those applications where an AVR could be limited, but where there is no need to use a big embedded OS. They are also plenty of integrated peripherals. Or perhaps you need an OS. If you depend on a commercial OS, somebody would have to buy a license. Linux is free and runs on ARM. NetBSD runs on ARM. I'm not sure about the other BSD variants. That's 1/2 :) I expect most of the code we would be interested in would be low level, just collect the data and pass it off to a PC to do the number crunching, display, and archiving. As such it doesn't need an OS. An embedded linux project can be very fun, but it is quite complex. If you need the OS, you first need the bootloader (U-boot or similar), and you must make it work with your hardware. Then the kernel, with the drivers for your hardware (there are a lot of them in the linux distributions, but some may require some tuning for your hardware, and also you can be in the need to write your own drivers for those peripherals that are currently not supported). And finaly, the user space application(s). Lots of fun, I can guarantee it :) Best regards, Javier -- Javier HerreroEMAIL: jherr...@hvsistemas.com HV Sistemas S.L. PHONE: +34 949 336 806 Los Charcones, 17 FAX: +34 949 336 792 19170 El Casar - Guadalajara - Spain WEB: http://www.hvsistemas.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Updated Shera controller
Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] What do you use?
I am working with an older Motorola M12M here to develop a new system for specialized industrial application. Simply using it for the dev. work and such and will finish off project with the new much better SM product and the plan is to go FPGA for the thinking. Biggest issue and have never posted about it is that while the task here is only to essentially end up with what will need be known freq's in particular bands with NIST type accuracy to drive the project, the big difficulty is NOT using an oscillator like any of my ovens. Lots of ways to go, but nothing readily seems tight enough to not make the entire affair a massive hassle to get to accuracy. Simple would be have a darn time base that has some accuracy - that spoils the cost. Maybe I should install a metronome??? Yeah not yet found any cheap alternative that looks suitable to go from. Guess that was not what you asked either. Old M12M here. ___ 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] Updated Shera controller
- Original Message From: Hal Murray hmur...@megapathdsl.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thu, July 29, 2010 12:48:55 AM Subject: Re: [time-nuts] Updated Shera controller stanley_reyno...@yahoo.com said: Full circle back to the software, the number of units sold, the cost per hour and time to complete project would determine the software cost. Would not surprise me if the software would be the biggest expense till you break the 1000 unit mark unless the cost per hour was very low. As a hardware guy at heart it is hard for me to assign a cost/value to software ;-) That line of thinking is probably appropriate for a commercial project. For a hobby/volunteer project, software can be free. Consider Lady Heather as an example. In this context, there are two types of software. There is the software you run on the board you build. There is also the software you use to develop the software you run. I'm assuming a volunteer would write the software just like volunteers have designed boards. snip Some with well stocked junk boxes could argue the hardware was below market cost as well. But my point was the software was much more of a factor than the hardware if we assign value to each part. Yes Lady Heather is free to many but not all, the author and others would be rich if paid a fair price for their work. Thank you time-nuts for your time. Stanley ___ 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] FS: 5370A
Interesting you were going to add a fan. I have 4 5370s and measured the temps on that heat sink. They were all the same pretty much, so figured HP knew what they were doing. But it really does feel pretty hot. Pretty sure what I have picked them up for is not what you paid. Plus they are heavy. Good luck with finding a new home. They are a nice counter. On Thu, Jul 29, 2010 at 1:57 AM, Joseph Gray jg...@zianet.com wrote: Ok guys, it has been sitting on my floor far too long and I don't know when I'll get around to working on it. When I last messed with it, I went through quite a few of the performance tests and IIRC, most passed. It measures frequency ok, but it's off a bit on TI measurements. I intended to open it up and get things up to spec, but never finished. It does have one intermittant BNC on the front panel that I haven't re-soldered yet. I'm not sure what the current prices are, but I know what I paid for it. How about $100 (less than I paid) plus shipping? Continental US only, please. I'll even throw in a fan that I was going to mount on the back heatsink. PM me. No need to clog up the list. Joe Gray W5JG ___ 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] Updated Shera controller
Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Please send your paypal for PicTic II PCBs
Op 22 jul 2010, om 16:37 heeft Stanley Reynolds het volgende geschreven: Just tried to invoice the ones not paid yet but paypal doesn't allow enough time for me to complete the invoice and thinks it is OK to dump my work up to that point, note to self sell ebay stock short and use money to hire someone to do paperwork. The people in the EU / UK I wanted to ship at the same time to save on shipping but not delay the ones who have paid. No hurry for other locations as they can be shipped one at a time. Stanley ___ 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] Updated Shera controller
Bert, I forgot the Shera Board, my first device, which probably could be a bit tuned... Arnold Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Updated Shera controller
Arnold how are you controlling the Rb with the Tbolt? Bert In a message dated 7/29/2010 11:10:16 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] FS: 5370A
Mine have extra heatsink clamped on with 1 inch c-clamps... Don paul swed Interesting you were going to add a fan. I have 4 5370s and measured the temps on that heat sink. They were all the same pretty much, so figured HP knew what they were doing. But it really does feel pretty hot. Pretty sure what I have picked them up for is not what you paid. Plus they are heavy. Good luck with finding a new home. They are a nice counter. On Thu, Jul 29, 2010 at 1:57 AM, Joseph Gray jg...@zianet.com wrote: Ok guys, it has been sitting on my floor far too long and I don't know when I'll get around to working on it. When I last messed with it, I went through quite a few of the performance tests and IIRC, most passed. It measures frequency ok, but it's off a bit on TI measurements. I intended to open it up and get things up to spec, but never finished. It does have one intermittant BNC on the front panel that I haven't re-soldered yet. I'm not sure what the current prices are, but I know what I paid for it. How about $100 (less than I paid) plus shipping? Continental US only, please. I'll even throw in a fan that I was going to mount on the back heatsink. PM me. No need to clog up the list. Joe Gray W5JG ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What do you use?
I have some old GR tuning forks; they're kinda noisy and bulky, but really simple! Don Douglas Wire - PUPCo Studios I am working with an older Motorola M12M here to develop a new system for specialized industrial application. Simply using it for the dev. work and such and will finish off project with the new much better SM product and the plan is to go FPGA for the thinking. Biggest issue and have never posted about it is that while the task here is only to essentially end up with what will need be known freq's in particular bands with NIST type accuracy to drive the project, the big difficulty is NOT using an oscillator like any of my ovens. Lots of ways to go, but nothing readily seems tight enough to not make the entire affair a massive hassle to get to accuracy. Simple would be have a darn time base that has some accuracy - that spoils the cost. Maybe I should install a metronome??? Yeah not yet found any cheap alternative that looks suitable to go from. Guess that was not what you asked either. Old M12M here. ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PICTIC II PIC chip group order (update)
Robert: Do you have two left? Thanks Don Robert Darlington Hi all, Just a reminder that I'm going to place an order for the PICTIC PIC chips tonight for those in the USA that want them. The price is $10.00 for the first one, $2.50 for each additional, including shipping and programming. 1 would be $10.00 even, 3 would be $15.00, etc. You can PayPal me at rdarling...@gmail.com or cut me a personal check, cash, whatever. Pretty much anything other than livestock! Just make sure I have a good shipping address.I'll order a few extras for stragglers that missed this. Thanks, Bob, N3XKB ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Rb Tuning
Hi Something to think about as you go to tune your Rb: 1) If the tune range is 5 V for 5 x 10^-9 (+/- 2.5x10^-9) then its a ppb / volt or a ppt / mV. (from http://www.ham-radio.com/sbms/LPRO-101.pdf) 2) If you are after a goal of 1x10^-13, then thats 0.1 ppt and 0.1 mV 3) The Rb pulls a half amp to an amp running normally. 4) One foot of number 18 wire is 6.3 mOhms (from http://www.thelearningpit.com/elec/tools/tables/Wire_table.htm) 5) One amp in that wire will give you 6.3 mV 6) Copper wire has a temperature coefficient of 0.00393 / C at room (1% change in 2.5 C) (from http://www.cirris.com/testing/temperature/copper.html) 7) The current in the Rb heater will move around a bit The current and resistance would have to be stable to 1/630 or 0.15% for it to be negligible relative to your goal. At 1.5% it would be the same as the goal. Your Rb may only be ½ as sensitive as the one in the example. It also may pull ½ A compared to the one amp I used. That gets you to a stability that still needs to be better than 1%. I suspect you also will find that the connections to the wire have a *lot* more resistance than the foot of wire back to 0.1% land. Theres also the chance that you needed more than a foot of wire or used something smaller than number 18. For 10 feet you would need number 8 to get the same resistance. There are a couple of solutions: 1) Reference your tuning voltage directly to the Rb ground via sense leads. 2) Float the controller and single point ground it at the Rb 3) Attenuate the control signal at the Rb by 600:1, your tune range is now 8x10^-12 (or +/- 4x10-12). 4) Bolt everything to a 6 x 6 copper buss bar. (or is that to small .) Sense leads probably bring in another amp in the design. Its stability could be an issue. Floating the controller may or may not be possible depending on the design. Attenuating the control voltage at the Rb by 10:1 looks like a real good idea, regardless of what else you do. Of course thats not the whole story. The connections also have thermo electric effects. So many things to worry about. Bob ___ 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] FS: 5370A
Interesting so others found them a bit to warm also On Thu, Jul 29, 2010 at 12:18 PM, Don Latham d...@montana.com wrote: Mine have extra heatsink clamped on with 1 inch c-clamps... Don paul swed Interesting you were going to add a fan. I have 4 5370s and measured the temps on that heat sink. They were all the same pretty much, so figured HP knew what they were doing. But it really does feel pretty hot. Pretty sure what I have picked them up for is not what you paid. Plus they are heavy. Good luck with finding a new home. They are a nice counter. On Thu, Jul 29, 2010 at 1:57 AM, Joseph Gray jg...@zianet.com wrote: Ok guys, it has been sitting on my floor far too long and I don't know when I'll get around to working on it. When I last messed with it, I went through quite a few of the performance tests and IIRC, most passed. It measures frequency ok, but it's off a bit on TI measurements. I intended to open it up and get things up to spec, but never finished. It does have one intermittant BNC on the front panel that I haven't re-soldered yet. I'm not sure what the current prices are, but I know what I paid for it. How about $100 (less than I paid) plus shipping? Continental US only, please. I'll even throw in a fan that I was going to mount on the back heatsink. PM me. No need to clog up the list. Joe Gray W5JG ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FS: 5370A
Hi Drift / failure of the three terminal regulators on the rear heat sink seems to be an often reported issue. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Thursday, July 29, 2010 1:02 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] FS: 5370A Interesting so others found them a bit to warm also On Thu, Jul 29, 2010 at 12:18 PM, Don Latham d...@montana.com wrote: Mine have extra heatsink clamped on with 1 inch c-clamps... Don paul swed Interesting you were going to add a fan. I have 4 5370s and measured the temps on that heat sink. They were all the same pretty much, so figured HP knew what they were doing. But it really does feel pretty hot. Pretty sure what I have picked them up for is not what you paid. Plus they are heavy. Good luck with finding a new home. They are a nice counter. On Thu, Jul 29, 2010 at 1:57 AM, Joseph Gray jg...@zianet.com wrote: Ok guys, it has been sitting on my floor far too long and I don't know when I'll get around to working on it. When I last messed with it, I went through quite a few of the performance tests and IIRC, most passed. It measures frequency ok, but it's off a bit on TI measurements. I intended to open it up and get things up to spec, but never finished. It does have one intermittant BNC on the front panel that I haven't re-soldered yet. I'm not sure what the current prices are, but I know what I paid for it. How about $100 (less than I paid) plus shipping? Continental US only, please. I'll even throw in a fan that I was going to mount on the back heatsink. PM me. No need to clog up the list. Joe Gray W5JG ___ 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Please send your paypal for PicTic II PCBs
Hi Stan, Please tell me how to pay you through Paypal. What is your Paypal account name? As soon as I get it I would be happy to pay you. Sincere thanks, David - Original Message - From: Henk h...@deriesp.demon.nl To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, July 29, 2010 8:11:46 AM Subject: Re: [time-nuts] Please send your paypal for PicTic II PCBs Op 22 jul 2010, om 16:37 heeft Stanley Reynolds het volgende geschreven: Just tried to invoice the ones not paid yet but paypal doesn't allow enough time for me to complete the invoice and thinks it is OK to dump my work up to that point, note to self sell ebay stock short and use money to hire someone to do paperwork. The people in the EU / UK I wanted to ship at the same time to save on shipping but not delay the ones who have paid. No hurry for other locations as they can be shipped one at a time. Stanley ___ 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] Updated Shera controller
No problem for the PRS10 - there is an external pps input. For the FRK-RbO I don't have a practical solution yet, because I don't have a manual with circuit diagram found for this 5 MHz model. This RbO is actually running free, drift controlled by an external resistor set by two 10 turns potentiometers. I think it should be possible to inject a current instead. The control by eg. the Shera controller need some modifs for this purpose which I have not yet done. The time constant need to be modified too I think. Arnold Am 29.07.2010 18:09, schrieb ewkeh...@aol.com: Arnold how are you controlling the Rb with the Tbolt? Bert In a message dated 7/29/2010 11:10:16 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and what they use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message 60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller ? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Updated Shera controller
Arnold Have you actually done it with the PRS10 and what was the result? Bert In a message dated 7/29/2010 1:52:08 P.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: No problem for the PRS10 - there is an external pps input. For the FRK-RbO I don't have a practical solution yet, because I don't have a manual with circuit diagram found for this 5 MHz model. This RbO is actually running free, drift controlled by an external resistor set by two 10 turns potentiometers. I think it should be possible to inject a current instead. The control by eg. the Shera controller need some modifs for this purpose which I have not yet done. The time constant need to be modified too I think. Arnold Am 29.07.2010 18:09, schrieb ewkeh...@aol.com: Arnold how are you controlling the Rb with the Tbolt? Bert In a message dated 7/29/2010 11:10:16 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on otherimprovements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and whatthey use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Can Lady Heather Keep Computer Clock On Time?
Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Can Lady Heather Keep Computer Clock On Time?
Hi My observation is that the displayed clock on LH can be off by 10 seconds. That's with the current beta code and Windows 7 on a quad processor machine or under XP on a dual core machine. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Thursday, July 29, 2010 2:04 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can Lady Heather Keep Computer Clock On Time? Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Updated Shera controller
Hi Bert: The PRS10 can use it's external 1 PPS input two ways. 1) as the input for a GPSDO, or 2) Time Tag (RS-232 command TT) of the input pulse http://www.prc68.com/I/PRS10.shtml Have Fun, Brooke Clarke http://www.PRC68.com ewkeh...@aol.com wrote: Arnold Have you actually done it with the PRS10 and what was the result? Bert In a message dated 7/29/2010 1:52:08 P.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: No problem for the PRS10 - there is an external pps input. For the FRK-RbO I don't have a practical solution yet, because I don't have a manual with circuit diagram found for this 5 MHz model. This RbO is actually running free, drift controlled by an external resistor set by two 10 turns potentiometers. I think it should be possible to inject a current instead. The control by eg. the Shera controller need some modifs for this purpose which I have not yet done. The time constant need to be modified too I think. Arnold Am 29.07.2010 18:09, schrieb ewkeh...@aol.com: Arnold how are you controlling the Rb with the Tbolt? Bert In a message dated 7/29/2010 11:10:16 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on otherimprovements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and whatthey use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dk writes: In message60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is a normal condition if a average time interval of zero between local pps and GPS pps is the aim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Can Lady Heather Keep Computer Clock On Time?
with the assumption that he seems to be fine right after a sync, (seemingly supported in the OP) reconfiguring the windows time service to update frequently seems to me to be the easiest answer. under xp you can do so thus: http://support.microsoft.com/kb/314054 _eric On Thu, Jul 29, 2010 at 11:13 AM, Bob Camp li...@rtty.us wrote: Hi My observation is that the displayed clock on LH can be off by 10 seconds. That's with the current beta code and Windows 7 on a quad processor machine or under XP on a dual core machine. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Thursday, July 29, 2010 2:04 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can Lady Heather Keep Computer Clock On Time? Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- --Eric _ Eric Garner ___ 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] Can Lady Heather Keep Computer Clock On Time?
Or even better download a real NTP for windows. http://www.meinberg.de/english/sw/ntp.htm#ntp_nt_stable -- Björn with the assumption that he seems to be fine right after a sync, (seemingly supported in the OP) reconfiguring the windows time service to update frequently seems to me to be the easiest answer. under xp you can do so thus: http://support.microsoft.com/kb/314054 _eric On Thu, Jul 29, 2010 at 11:13 AM, Bob Camp li...@rtty.us wrote: Hi My observation is that the displayed clock on LH can be off by 10 seconds. That's with the current beta code and Windows 7 on a quad processor machine or under XP on a dual core machine. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Thursday, July 29, 2010 2:04 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can Lady Heather Keep Computer Clock On Time? Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- --Eric _ Eric Garner ___ 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] Updated Shera controller
Thank you Brooke I have only been with this group for a year so I am not aware of all past dialog. What has been the result driving the PRS10 with an external source and was it a GPS or a Tbolt? I am not trying to be cute but if there is an alternative with test data I would like to buy one and compare it with what I presently have. If I am repetitive I shut up, but the proliferation of Rb's it makes sense to lock them to GPS, listening to some new members. To day Rb's are cheaper than good OCXO's! Bert Kehren In a message dated 7/29/2010 2:16:01 P.M. Eastern Daylight Time, bro...@pacific.net writes: Hi Bert: The PRS10 can use it's external 1 PPS input two ways. 1) as the input for a GPSDO, or 2) Time Tag (RS-232 command TT) of the input pulse http://www.prc68.com/I/PRS10.shtml Have Fun, Brooke Clarke http://www.PRC68.com ewkeh...@aol.com wrote: Arnold Have you actually done it with the PRS10 and what was the result? Bert In a message dated 7/29/2010 1:52:08 P.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: No problem for the PRS10 - there is an external pps input. For the FRK-RbO I don't have a practical solution yet, because I don't have a manual with circuit diagram found for this 5 MHz model. This RbO is actually running free, drift controlled by an external resistor set by two 10 turns potentiometers. I think it should be possible to inject a current instead. The control by eg. the Shera controller need some modifs for this purpose which I have not yet done. The time constant need to be modified too I think. Arnold Am 29.07.2010 18:09, schrieb ewkeh...@aol.com: Arnold how are you controlling the Rb with the Tbolt? Bert In a message dated 7/29/2010 11:10:16 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT Am 29.07.2010 13:50, schrieb ewkeh...@aol.com: Arnold what do you use? Bert Kehren In a message dated 7/29/2010 7:02:06 A.M. Eastern Daylight Time, arnold.ti...@gmx.de writes: I do, and I am also interested on other improvements! Regards, Arnold Am 29.07.2010 12:49, schrieb ewkeh...@aol.com: Hi I think it would be nice to have a show of hands as to how many are locking a Rb to GPS and whatthey use. Bert Kehren In a message dated 7/29/2010 4:00:31 A.M. Eastern Daylight Time, p...@phk.freebsd.dkwrites: In message60eb5e7c69594f49b830463dc322e...@athlon, Ulrich Bangert writes: Uhm, isn't this exactly where you want to use the still-smelling-like-brand-new-car PICTIC II with a good DAC and a microcontroller? I guess the PICTIC II is not very good when stop pulses arrive BEFORE start pulses which is anormal condition if a average time interval of zero between local pps and GPS pps is theaim. So configure it to use a standard offset of one Xtal/Rb period ? ___ 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] Can Lady Heather Keep Computer Clock On Time?
Hi Eric: That seems to be for a time server. He is just using an ordinary PC and NTP to set it's time. Have Fun, Brooke Clarke http://www.PRC68.com Eric Garner wrote: with the assumption that he seems to be fine right after a sync, (seemingly supported in the OP) reconfiguring the windows time service to update frequently seems to me to be the easiest answer. under xp you can do so thus: http://support.microsoft.com/kb/314054 _eric On Thu, Jul 29, 2010 at 11:13 AM, Bob Campli...@rtty.us wrote: Hi My observation is that the displayed clock on LH can be off by 10 seconds. That's with the current beta code and Windows 7 on a quad processor machine or under XP on a dual core machine. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Thursday, July 29, 2010 2:04 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can Lady Heather Keep Computer Clock On Time? Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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] Can Lady Heather Keep Computer Clock On Time?
see the section of the article Configuring the Windows Time service to use an external time source that details how to reconfigure the winXP time sync service so that it polls and external server for time at a specified interval. On Thu, Jul 29, 2010 at 12:10 PM, Brooke Clarke bro...@pacific.net wrote: Hi Eric: That seems to be for a time server. He is just using an ordinary PC and NTP to set it's time. Have Fun, Brooke Clarke http://www.PRC68.com Eric Garner wrote: with the assumption that he seems to be fine right after a sync, (seemingly supported in the OP) reconfiguring the windows time service to update frequently seems to me to be the easiest answer. under xp you can do so thus: http://support.microsoft.com/kb/314054 _eric On Thu, Jul 29, 2010 at 11:13 AM, Bob Campli...@rtty.us wrote: Hi My observation is that the displayed clock on LH can be off by 10 seconds. That's with the current beta code and Windows 7 on a quad processor machine or under XP on a dual core machine. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Brooke Clarke Sent: Thursday, July 29, 2010 2:04 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Can Lady Heather Keep Computer Clock On Time? Hi: I have a friend who's setting up an observatory and the PC that controls the telescope needs to have an accurate clock. The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. Running the observatory is like flying a 747, i.e. there's a lot to do and the time needs to be handled automatically, not by manual NTP updates. I know that TAC32 and a Motorola GPS will do this and you have a lot of options of how it does it. For example at a specified time interval or when the computer clock differs from GPS by a specified amount of time (50 ms in this case). What are the options in LH? I ask because it's a lower cost option then the Motorola GPS plus TAC32 option or building a NTP time server. -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ 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. -- --Eric _ Eric Garner ___ 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] Please send your paypal for PicTic II PCBs
My paypal account is stanley_reyno...@yahoo.com boards are 9.50 usd each which includes shipping Stanley - Original Message From: bell@comcast.net bell@comcast.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thu, July 29, 2010 12:24:39 PM Subject: Re: [time-nuts] Please send your paypal for PicTic II PCBs Hi Stan, Please tell me how to pay you through Paypal. What is your Paypal account name? As soon as I get it I would be happy to pay you. Sincere thanks, David - Original Message - From: Henk h...@deriesp.demon.nl To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, July 29, 2010 8:11:46 AM Subject: Re: [time-nuts] Please send your paypal for PicTic II PCBs Op 22 jul 2010, om 16:37 heeft Stanley Reynolds het volgende geschreven: Just tried to invoice the ones not paid yet but paypal doesn't allow enough time for me to complete the invoice and thinks it is OK to dump my work up to that point, note to self sell ebay stock short and use money to hire someone to do paperwork. The people in the EU / UK I wanted to ship at the same time to save on shipping but not delay the ones who have paid. No hurry for other locations as they can be shipped one at a time. Stanley ___ 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] HP 5335A Option 040
Hi, there exist three manuals, 5335-90005 - Serial #2024A and below, 1980, preliminary pdf manual on agilent.com 5335-90021 - Serial #2224A and below, 1983, pdf from Artekmedia, very good scan for $7.50 5335-90044 - Serial #3154A and below, 1994, very good reprint from manualsplus for about 70$ If you don't have the latest device, Artek Media document is absolutely sufficient for description of Opt. 040, i.e. HPIB instruction set and schematics. (SW is different, also input amplifier / front end A12 and amplifier support A11) Btw.: I've got a nice 5335A with ser no 2820, Opt. 10, 30 , 40 (10811 oven, 1,3Ghz C-input - latest divide-by-64 version, and full front end remote steering). I've found out, that it definitely resolves 1ns in Time and Freq. measurements, in contrast to 2ns as stated by all the latest specs. in the manuals and all the HP catalogues. Gordon, and other 5335 owners - would you please check your instruments on that, to find out if firmware has changed later on, or simply if the specification is wrong? I get 11 significant digits over the bus and on the display, if I measure for 100s. I'd expect 12 digits for 1000s at least over the bus, as 14 digits are reserved for the mantissa (incl. sign and decimal point) but nothing happens. Anybody got an idea, how to get more digits, perhaps with undocumented commands? This counter potentially delivers nearly unlimited resolution, as the overflow is counted in many additional bytes, which I would like to read out. Thanks - Frank ___ 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] Rb Tuning
Attenuating the control voltage near the point of use is always a good idea when you are concerned about common mode or ground noise and particularly when you have excess dynamic range, but you have to consider the noise added by the divider. Some filtering may be required, and use as low a set of resistor values as practical. Didier Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Bob Camp li...@rtty.us Sender: time-nuts-boun...@febo.com Date: Thu, 29 Jul 2010 12:41:47 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Rb Tuning Hi Something to think about as you go to tune your Rb: 1) If the tune range is 5 V for 5 x 10^-9 (+/- 2.5x10^-9) then it’s a ppb / volt or a ppt / mV. (from http://www.ham-radio.com/sbms/LPRO-101.pdf) 2) If you are after a goal of 1x10^-13, then that’s 0.1 ppt and 0.1 mV 3) The Rb pulls a half amp to an amp running normally. 4) One foot of number 18 wire is 6.3 mOhms (from http://www.thelearningpit.com/elec/tools/tables/Wire_table.htm) 5) One amp in that wire will give you 6.3 mV 6) Copper wire has a temperature coefficient of 0.00393 / C at room (1% change in 2.5 C) (from http://www.cirris.com/testing/temperature/copper.html) 7) The current in the Rb heater will move around a bit The current and resistance would have to be stable to 1/630 or 0.15% for it to be negligible relative to your goal. At 1.5% it would be the same as the goal. Your Rb may only be ½ as sensitive as the one in the example. It also may pull ½ A compared to the one amp I used. That gets you to a stability that still needs to be better than 1%. I suspect you also will find that the connections to the wire have a *lot* more resistance than the foot of wire – back to 0.1% land. There’s also the chance that you needed more than a foot of wire or used something smaller than number 18. For 10 feet you would need number 8 to get the same resistance. There are a couple of solutions: 1) Reference your tuning voltage directly to the Rb ground via sense leads. 2) Float the controller and single point ground it at the Rb 3) Attenuate the control signal at the Rb by 600:1, your tune range is now 8x10^-12 (or +/- 4x10-12). 4) Bolt everything to a 6” x 6” copper buss bar. (or is that to small ….) Sense leads probably bring in another amp in the design. It’s stability could be an issue. Floating the controller may or may not be possible depending on the design. Attenuating the control voltage at the Rb by 10:1 looks like a real good idea, regardless of what else you do. Of course that’s not the whole story. The connections also have thermo electric effects. So many things to worry about. Bob ___ 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] Faulty GPS SAT # 16 on Lady Heather
Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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] Faulty GPS SAT # 16 on Lady Heather
It seems it is beeing moved. 56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std Scheduled unusable 29 Jul 1345 UT to 30 Jul 0145 UT for repositioning maintenance (NANU 2010102) from ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt btw the Elmer Perkins Rb's beats most/all space CS out to a few days. Since the ground crew updates clock preditions every day, there is not that much need for the Cs _long_ term stability. -- Björn Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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] Faulty GPS SAT # 16 on Lady Heather
Elmer Perkins ?? I know of Perkin Elmer. 73, Dick, W1KSZ -Original Message- From: b...@lysator.liu.se Sent: Jul 29, 2010 5:41 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Faulty GPS SAT # 16 on Lady Heather It seems it is beeing moved. 56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std Scheduled unusable 29 Jul 1345 UT to 30 Jul 0145 UT for repositioning maintenance (NANU 2010102) from ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt btw the Elmer Perkins Rb's beats most/all space CS out to a few days. Since the ground crew updates clock preditions every day, there is not that much need for the Cs _long_ term stability. -- Björn Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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] Faulty GPS SAT # 16 on Lady Heather
Thanks! My mistake. Sorry! Should not be posting this late. -- Björn Elmer Perkins ?? I know of Perkin Elmer. 73, Dick, W1KSZ -Original Message- From: b...@lysator.liu.se Sent: Jul 29, 2010 5:41 PM To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] Faulty GPS SAT # 16 on Lady Heather It seems it is beeing moved. 56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std Scheduled unusable 29 Jul 1345 UT to 30 Jul 0145 UT for repositioning maintenance (NANU 2010102) from ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt btw the Elmer Perkins Rb's beats most/all space CS out to a few days. Since the ground crew updates clock preditions every day, there is not that much need for the Cs _long_ term stability. -- Björn Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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] Faulty GPS SAT # 16 on Lady Heather
Dunno, kinda like it as nickname. On 7/29/2010 5:02 PM, b...@lysator.liu.se wrote: Thanks! My mistake. Sorry! Should not be posting this late. -- Björn Elmer Perkins ?? I know of Perkin Elmer. 73, Dick, W1KSZ -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Can Lady Heather Keep Computer Clock On Time?
Yes, there is a time sync command that causes the program to set the system clock at periodic intervals or whenever it differs from GPS by a given amount. I'm still out on the Project From Hell Mark II and I don't remember all the gory details... I think /TSA on the command line says sync the time whenever the clocks differ by a millisecond. There is also /TSO /TSD /TSH /TSM /TSS to set it once, hourly, daily, every minute or second. There is also a /TSX command to specify the time offset from the Tbolt serial command to GPS (which is usually around 45 milliseconds). TS from the keyboard just syncs the clock once. ___ 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] Updated Shera controller
Have you looked at using the TAC32 software?. You can use the 53131A with it and a GPS receiver and time tag data and log the time interval. You can tell it to record a one second file, and a average file, for what ever you set the 53131A up to average, and it will also generate a satellite status file. TAC32 is designed for Motorola GPS receivers. It generates daily files automatically. Great for long term monitoring, I use it to compare a HP5065A rubidium to GPS via a Motorola M12+ receiver. Brian On 7/29/2010 10:09 AM, Arnold Tibus wrote: Bert, I'm using at the moment a thunderbolt (with spare for testpurposes using ext. other oscillators), a nice PRS10, a FRK-HLN-1A (5MHz with external doubler to 10 MHz) and several HP10811. I would like to build up with this a good and reliable reference (PPS and Frequ.). My dream would be a good autonom. TIC with timestamp possibility. At the moment the 53132A is doing a good job, but I miss the time stamp possibility and single measurements at defined time steps... regards Arnold,DK2WT ___ 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] Can Lady Heather Keep Computer Clock On Time?
The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. That looks like the classic time vs frequency problem. What is the primary goal? Pointing or tracking? Pointing requires time. Tracking requires frequency. If you are otherwise happy with Windows NTP sync, you may be able to solve your problem by doing a sync before pointing at another object if it's been more than N hours since the last sync. Long song and dance [Remember, I don't run Windows so I may screwup anything that's Windows specific.] The typical PC has 2 crystals. One runs at 32 KHz. The other is usually 14.xxx (from early PC days) that gets PLLed up to make clocks for the CPU and PCI and USB and ... The 32KHz crystal runs the battery backed RTC/TOY/CMOS clock. It's a watch crystal so it should be pretty good. But it's not very convenient for keeping time at the microsecond level. The 14 MHz crystal is stable, but typically not very accurate. (Remember low cost.) That's accurate at the PPM level, it will be fine if you just put a scope on it. It may be off by 50 PPM. Even if the hardware is good, the software can screw things up. (Linux is good at this. Current kernels don't get a consistent answer on the same hardware. Jumps by 200 PPM from boot to boot are not uncommon.) [Network and audio and ??? cards typically have a separate crystal. They are usually not convenient for timekeeping but if you do serious audio work you can measure it's actual frequency.] Let's see if I can do the math right... 3 hours is 10,000 seconds. 50 PPM times 10,000 seconds is 500,000 microseconds. So if the clock is off by 50 PPM, it will drift 1/2 second in 3 hours. Even 5 PPM will drift 50 ms in 3 hours. The main reason for running real ntpd rather than just setting the time occasionally is that ntpd will figure out how far off the frequency is and correct for it. ntpd calls that fudge factor drift and prints it out in PPM with 3 digits to the right of the decimal point. If all you need is 50 ms, you should be able to get that most of the time by just running ntpd over the net. It's sure worth a try. It may not be good enough if you have a crappy net connection or change from no-load to uploading tons of data from observations earlier in the evening. (Contact me off list if you want help in monitoring a ntp server and/or setting up and interpreting its log files.) Odds and ends to keep in mind... Modern PCs use spread spectrum clocking. That fudges things by 1 or 1/2 % or so which is huge in terms of PPM. The point is that you have to measure it. Just doing the math from the nominal CPU frequency isn't good enough. The actual frequency is temperature dependent, so things will change if you open the roof and let the cold air in or the CPU changes from idle (or off) to working hard. The ballpark is 1 PPM per 10 F. One of the classic ways to screwup timekeeping is to miss interrupts, typically because some other interrupt routine is running too long. This was easy to tickle on (very) old Linux systems that used PIO rather than DMA for disk transfers. I only mention it because you might have some strange hardware with buggy interrupt routines. Normal Windows clocks tick every 10 ms. Windows has a multimedia mode that does much better. There is a switch in the Registry or something. It may help to use that mode. I think you want to leave it on. (The Meinberg ntpd-installer package turns it on.) ntpd is both a client and server. A system will act as a client to get time from lower stratum servers and act as a server to provide time to higher stratum servers. -- 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] Rb Tuning
Hi A divider can do harm if poorly implemented. Knowing the source and load characteristics can be a big help. Bob On Jul 29, 2010, at 5:10 PM, Didier Juges did...@cox.net wrote: Attenuating the control voltage near the point of use is always a good idea when you are concerned about common mode or ground noise and particularly when you have excess dynamic range, but you have to consider the noise added by the divider. Some filtering may be required, and use as low a set of resistor values as practical. Didier Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Bob Camp li...@rtty.us Sender: time-nuts-boun...@febo.com Date: Thu, 29 Jul 2010 12:41:47 To: 'Discussion of precise time and frequency measurement'time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: [time-nuts] Rb Tuning Hi Something to think about as you go to tune your Rb: 1) If the tune range is 5 V for 5 x 10^-9 (+/- 2.5x10^-9) then it’s a ppb / volt or a ppt / mV. (from http://www.ham-radio.com/sbms/LPRO-101.pdf) 2) If you are after a goal of 1x10^-13, then that’s 0.1 ppt and 0.1 mV 3) The Rb pulls a half amp to an amp running normally. 4) One foot of number 18 wire is 6.3 mOhms (from http://www.thelearningpit.com/elec/tools/tables/Wire_table.htm) 5) One amp in that wire will give you 6.3 mV 6) Copper wire has a temperature coefficient of 0.00393 / C at room (1% change in 2.5 C) (from http://www.cirris.com/testing/temperature/copper.html) 7) The current in the Rb heater will move around a bit The current and resistance would have to be stable to 1/630 or 0.15% for it to be negligible relative to your goal. At 1.5% it would be the same as the goal. Your Rb may only be ½ as sensitive as the one in the example. It also may pull ½ A compared to the one amp I used. That gets you to a stability that still needs to be better than 1%. I suspect you also will find that the connections to the wire have a *lot* more resistance than the foot of wire – back to 0.1% land. There’s also the chance that you needed more than a foot of wire or used something smaller than number 18. For 10 feet you would need number 8 to get the same resistance. There are a couple of solutions: 1) Reference your tuning voltage directly to the Rb ground via sense leads. 2) Float the controller and single point ground it at the Rb 3) Attenuate the control signal at the Rb by 600:1, your tune range is now 8x10^-12 (or +/- 4x10-12). 4) Bolt everything to a 6” x 6” copper buss bar. (or is that to small ….) Sense leads probably bring in another amp in the design. It’s stability could be an issue. Floating the controller may or may not be possible depending on the design. Attenuating the control voltage at the Rb by 10:1 looks like a real good idea, regardless of what else you do. Of course that’s not the whole story. The connections also have thermo electric effects. So many things to worry about. Bob ___ 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] Faulty GPS SAT # 16 on Lady Heather
Hi The main need for Cs apparently is no longer an issue. Bob On Jul 29, 2010, at 5:41 PM, b...@lysator.liu.se wrote: It seems it is beeing moved. 56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std Scheduled unusable 29 Jul 1345 UT to 30 Jul 0145 UT for repositioning maintenance (NANU 2010102) from ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt btw the Elmer Perkins Rb's beats most/all space CS out to a few days. Since the ground crew updates clock preditions every day, there is not that much need for the Cs _long_ term stability. -- Björn Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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] Can Lady Heather Keep Computer Clock On Time?
Hi There is a standard NTP driver that talks Thunderbolt. The full blown NTP package is pretty easy to set up. It will hold ms accuracy slaved to a GPS. Bob On Jul 29, 2010, at 7:29 PM, Hal Murray hmur...@megapathdsl.net wrote: The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. That looks like the classic time vs frequency problem. What is the primary goal? Pointing or tracking? Pointing requires time. Tracking requires frequency. If you are otherwise happy with Windows NTP sync, you may be able to solve your problem by doing a sync before pointing at another object if it's been more than N hours since the last sync. Long song and dance [Remember, I don't run Windows so I may screwup anything that's Windows specific.] The typical PC has 2 crystals. One runs at 32 KHz. The other is usually 14.xxx (from early PC days) that gets PLLed up to make clocks for the CPU and PCI and USB and ... The 32KHz crystal runs the battery backed RTC/TOY/CMOS clock. It's a watch crystal so it should be pretty good. But it's not very convenient for keeping time at the microsecond level. The 14 MHz crystal is stable, but typically not very accurate. (Remember low cost.) That's accurate at the PPM level, it will be fine if you just put a scope on it. It may be off by 50 PPM. Even if the hardware is good, the software can screw things up. (Linux is good at this. Current kernels don't get a consistent answer on the same hardware. Jumps by 200 PPM from boot to boot are not uncommon.) [Network and audio and ??? cards typically have a separate crystal. They are usually not convenient for timekeeping but if you do serious audio work you can measure it's actual frequency.] Let's see if I can do the math right... 3 hours is 10,000 seconds. 50 PPM times 10,000 seconds is 500,000 microseconds. So if the clock is off by 50 PPM, it will drift 1/2 second in 3 hours. Even 5 PPM will drift 50 ms in 3 hours. The main reason for running real ntpd rather than just setting the time occasionally is that ntpd will figure out how far off the frequency is and correct for it. ntpd calls that fudge factor drift and prints it out in PPM with 3 digits to the right of the decimal point. If all you need is 50 ms, you should be able to get that most of the time by just running ntpd over the net. It's sure worth a try. It may not be good enough if you have a crappy net connection or change from no-load to uploading tons of data from observations earlier in the evening. (Contact me off list if you want help in monitoring a ntp server and/or setting up and interpreting its log files.) Odds and ends to keep in mind... Modern PCs use spread spectrum clocking. That fudges things by 1 or 1/2 % or so which is huge in terms of PPM. The point is that you have to measure it. Just doing the math from the nominal CPU frequency isn't good enough. The actual frequency is temperature dependent, so things will change if you open the roof and let the cold air in or the CPU changes from idle (or off) to working hard. The ballpark is 1 PPM per 10 F. One of the classic ways to screwup timekeeping is to miss interrupts, typically because some other interrupt routine is running too long. This was easy to tickle on (very) old Linux systems that used PIO rather than DMA for disk transfers. I only mention it because you might have some strange hardware with buggy interrupt routines. Normal Windows clocks tick every 10 ms. Windows has a multimedia mode that does much better. There is a switch in the Registry or something. It may help to use that mode. I think you want to leave it on. (The Meinberg ntpd-installer package turns it on.) ntpd is both a client and server. A system will act as a client to get time from lower stratum servers and act as a server to provide time to higher stratum servers. -- 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.
Re: [time-nuts] Can Lady Heather Keep Computer Clock On Time?
Hi Hal: The key thing is pointing, not tracking (where a guide star is commonly used). A TPoint model is made by pointing to known stars and the quality of the model depends on good computer time. Have Fun, Brooke Clarke http://www.PRC68.com Hal Murray wrote: The telescope can point to within arc seconds of a star and that implies that the computer clock needs to be within 50 ms. If he does a Windows NTP sync first thing in the evening after a few hours there's too big an error. That looks like the classic time vs frequency problem. What is the primary goal? Pointing or tracking? Pointing requires time. Tracking requires frequency. If you are otherwise happy with Windows NTP sync, you may be able to solve your problem by doing a sync before pointing at another object if it's been more than N hours since the last sync. Long song and dance [Remember, I don't run Windows so I may screwup anything that's Windows specific.] The typical PC has 2 crystals. One runs at 32 KHz. The other is usually 14.xxx (from early PC days) that gets PLLed up to make clocks for the CPU and PCI and USB and ... The 32KHz crystal runs the battery backed RTC/TOY/CMOS clock. It's a watch crystal so it should be pretty good. But it's not very convenient for keeping time at the microsecond level. The 14 MHz crystal is stable, but typically not very accurate. (Remember low cost.) That's accurate at the PPM level, it will be fine if you just put a scope on it. It may be off by 50 PPM. Even if the hardware is good, the software can screw things up. (Linux is good at this. Current kernels don't get a consistent answer on the same hardware. Jumps by 200 PPM from boot to boot are not uncommon.) [Network and audio and ??? cards typically have a separate crystal. They are usually not convenient for timekeeping but if you do serious audio work you can measure it's actual frequency.] Let's see if I can do the math right... 3 hours is 10,000 seconds. 50 PPM times 10,000 seconds is 500,000 microseconds. So if the clock is off by 50 PPM, it will drift 1/2 second in 3 hours. Even 5 PPM will drift 50 ms in 3 hours. The main reason for running real ntpd rather than just setting the time occasionally is that ntpd will figure out how far off the frequency is and correct for it. ntpd calls that fudge factor drift and prints it out in PPM with 3 digits to the right of the decimal point. If all you need is 50 ms, you should be able to get that most of the time by just running ntpd over the net. It's sure worth a try. It may not be good enough if you have a crappy net connection or change from no-load to uploading tons of data from observations earlier in the evening. (Contact me off list if you want help in monitoring a ntp server and/or setting up and interpreting its log files.) Odds and ends to keep in mind... Modern PCs use spread spectrum clocking. That fudges things by 1 or 1/2 % or so which is huge in terms of PPM. The point is that you have to measure it. Just doing the math from the nominal CPU frequency isn't good enough. The actual frequency is temperature dependent, so things will change if you open the roof and let the cold air in or the CPU changes from idle (or off) to working hard. The ballpark is 1 PPM per 10 F. One of the classic ways to screwup timekeeping is to miss interrupts, typically because some other interrupt routine is running too long. This was easy to tickle on (very) old Linux systems that used PIO rather than DMA for disk transfers. I only mention it because you might have some strange hardware with buggy interrupt routines. Normal Windows clocks tick every 10 ms. Windows has a multimedia mode that does much better. There is a switch in the Registry or something. It may help to use that mode. I think you want to leave it on. (The Meinberg ntpd-installer package turns it on.) ntpd is both a client and server. A system will act as a client to get time from lower stratum servers and act as a server to provide time to higher stratum servers. ___ 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] Faulty GPS SAT # 16 on Lady Heather
Yes, forecast downtime due to delta V maneuvering. I believe it's related to the reorganisation of the constellation from 21+3 to 24+3: http://blogs.agi.com/navigationAccuracy/?p=315 Henry On Thu, Jul 29, 2010 at 2:41 PM, b...@lysator.liu.se wrote: It seems it is beeing moved. 56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std Scheduled unusable 29 Jul 1345 UT to 30 Jul 0145 UT for repositioning maintenance (NANU 2010102) from ftp://tycho.usno.navy.mil/pub/gps/gpstd.txt btw the Elmer Perkins Rb's beats most/all space CS out to a few days. Since the ground crew updates clock preditions every day, there is not that much need for the Cs _long_ term stability. -- Björn Once again, one of the 8 received satellites (#16) delivers no contribution to the time ensmble, although it got is over 40dbc strength. Lady Heather (beta 3.00) shows a hollow circle in the diagram, marked yellow in the list, and it has zero CLOCK BIAS and ACCU=0. Does anybody know, if that satellite is defect (e.g. Cs down), or if it has a special task, i.e. military purposes only? Frank ___ 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. -- Henry Hallam Sent from my Laptop ___ 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.
