Re: [time-nuts] Oncore, Trimble Antennae
Hi Brian, On Wed, 2008-10-22 at 00:46 -0500, Brian Kirby wrote: All the antenna's I have played with have been +5 volts for power. Is anyone aware of any other voltages ? (I know Garmin used +3V for some) Antcom antennas are often 2.5V to 24V. Aeroantenna's standard versions eats 5V to 18V. Novatel antennas are 4.5V to 18V Have seen 28V antennas too. ;-) Javad antennas are often 3V to 12V -- Björn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5335a opt 40 addendum
Dear Norm, Norman J McSweyn wrote: Magnus, Thanks for the enlightenment! I modified the driver that NI has on their site. Works. Have been manually setting the trigger levels on the front panel. Now know how to use the -40 to do it. Great! Happy to help! I'll further modify the driver in the AM. The manual I have doesn't have programming example 13. I haven't looked in detail, but I *think* the HP5335A manual on the HP site is the same as I have, and then you should have all the details you need. I take it that the instrument will trigger automatically when the conditions are met? Indeed it does. I'm comparing the 1pps output from an M12+t to the divided down 10MHz out from a Thunderbolt. Next hurdle is to do something with the collected data. Way to go! You should learn to calculate Allan deviation and friends. Not to hard. You should learn to estimate drift rate and subtract that from measurements, since that is often ignored and the drift rate will form a lower floor for longer measurement runs. This is an error which is either canceled by locking or by software. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] OT: Open Hardware Repository
Dear nuts, Sorry for this posting, only indirectly related to timing. For a long time I've been toying with the idea of a web-based Open Hardware Repository, and now it looks like we could allocate some resources to building it. Here are some preliminary and unofficial specs: http://ab-dep-co-ht.web.cern.ch/ab-dep-co-ht/documents/2008/Hardware/OHRFuncSpec.pdf. I have not found anywhere a kind of repository which would match these requirements completely. It's intended to be for PCB design, in a much more humble scale, what source forge is for software or opencores.org is for HDL. Since many of the designs we'd put there are timing-related, I thought I'd ask you for feedback: - Do you think this is a good idea? - Does this exist already somewhere? - Any comments on the specs? Feel free to answer directly to me if you think this is really off topic. I would not like to spoil the fine SNR of this list. If I see there's lots of interest I will post a summary. Thanks, Javier ___ time-nuts mailing 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] Oncore, Trimble Antennae
Matthew Smith wrote: Quoth Chuck Harris at 2008-10-22 15:01... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. I always try to do that kind of thing (when I can) in my designs... I wonder if they did? What, and use an extra component? The accountants would never allow it! That's really kind of funny, in 29 years as an engineer, I have never had an accountant talk to me about design decisions. I tell them what it will cost, and they say ok. -Chuck Harris ___ time-nuts mailing 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] Oncore, Trimble Antennae
2008/10/23 Chuck Harris [EMAIL PROTECTED]: Matthew Smith wrote: Quoth Chuck Harris at 2008-10-22 15:01... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. I always try to do that kind of thing (when I can) in my designs... I wonder if they did? What, and use an extra component? The accountants would never allow it! That's really kind of funny, in 29 years as an engineer, I have never had an accountant talk to me about design decisions. I tell them what it will cost, and they say ok. So you never worked for Microsoft on the Xbox then :) 73 Steve -- Steve Rooke - ZL3TUV G8KVD Omnium finis imminet ___ time-nuts mailing 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] Oncore, Trimble Antennae
On 10/21/08 9:31 PM, Chuck Harris [EMAIL PROTECTED] wrote: Tom Van Baak wrote: Both the Trimble and Motorola modules use active antennae with 5V power - what I don't know is whether they are the same polarity. all my trimbles and oncores have +5 on center, ground on shield... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. But not so trivial to provide the DC blocks in the ground side of the coax. The LNA is almost certainly some MMIC with RF ground==Vss And, don't forget that these are cost sensitive devices. 4 diodes and their installation and board real estate costs money, as would the extra couple capacitors for the DC blocks, etc. Jim ___ time-nuts mailing 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] Oncore, Trimble Antennae
Steve Rooke wrote: 2008/10/23 Chuck Harris [EMAIL PROTECTED]: Matthew Smith wrote: Quoth Chuck Harris at 2008-10-22 15:01... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. I always try to do that kind of thing (when I can) in my designs... I wonder if they did? What, and use an extra component? The accountants would never allow it! That's really kind of funny, in 29 years as an engineer, I have never had an accountant talk to me about design decisions. I tell them what it will cost, and they say ok. So you never worked for Microsoft on the Xbox then :) Nope! I have always worked for companies that are well out of the Fortune 500 range. I am a Renaissance man, so I find that smaller companies better appreciate my wide range of skills. -Chuck Harris ___ time-nuts mailing 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] Oncore, Trimble Antennae
Lux, James P wrote: On 10/21/08 9:31 PM, Chuck Harris [EMAIL PROTECTED] wrote: Tom Van Baak wrote: Both the Trimble and Motorola modules use active antennae with 5V power - what I don't know is whether they are the same polarity. all my trimbles and oncores have +5 on center, ground on shield... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. But not so trivial to provide the DC blocks in the ground side of the coax. The LNA is almost certainly some MMIC with RF ground==Vss Not any worse than providing the DC block on the center of the coax. And, don't forget that these are cost sensitive devices. 4 diodes and their installation and board real estate costs money, as would the extra couple capacitors for the DC blocks, etc. There is certain to be one diode on the hot lead anyway... engineers get nervous when they leave out stuff like that.. so adding a bridge would eliminate that diode. A quick check of Mouser gives me a cost difference (qty 1000) of one dime for the added bridge and capacitor... 12 cents if there was no diode in the original circuit. Circuit boards on devices like hockey puck antennas tend to be sparsely populated, so I don't think it would make any difference there. It would be worth the cost if the antenna was meant to be a universal device, but probably not if it was intended to be used on only one receiver. -Chuck Harris ___ time-nuts mailing 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] Oncore, Trimble Antennae
On 10/22/08 6:04 AM, Chuck Harris [EMAIL PROTECTED] wrote: Matthew Smith wrote: Quoth Chuck Harris at 2008-10-22 15:01... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. I always try to do that kind of thing (when I can) in my designs... I wonder if they did? What, and use an extra component? The accountants would never allow it! That's really kind of funny, in 29 years as an engineer, I have never had an accountant talk to me about design decisions. I tell them what it will cost, and they say ok. Lucky you... In the consumer electronics world, they do BOM scrubs and whole multi work-year analyses to figure out how to remove a few square millimeters of PWB, or even better, what's the trade between some jumpers and a single sided board and a double sided board, and do we really need plated through holes. I worked on a project where they spent about 4-6 work months to eliminate a couple capacitors at a nickle each. When you're making 10,000,000 units, that nickle per cap turns into a million bucks, many times the few tens of $K the engineering time cost. In the space electronics world, you'd do the same BOM scrub, but there the idea is to eliminate parts that might fail, or add mass, or require testing (each different part in the part list adds something like $5K-$10K from a testing, inventory control, etc. standpoint) Jim ___ time-nuts mailing 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] Oncore, Trimble Antennae
On 10/22/08 7:20 AM, Chuck Harris [EMAIL PROTECTED] wrote: Lux, James P wrote: On 10/21/08 9:31 PM, Chuck Harris [EMAIL PROTECTED] wrote: Tom Van Baak wrote: Both the Trimble and Motorola modules use active antennae with 5V power - what I don't know is whether they are the same polarity. all my trimbles and oncores have +5 on center, ground on shield... I'd be interested to know if any antennas are in fact the other way around. Never even considered that. It would have been fairly trivial for them to put a bridge rectifier before the amplifier's power stuff, allowing for either polarity. But not so trivial to provide the DC blocks in the ground side of the coax. The LNA is almost certainly some MMIC with RF ground==Vss Not any worse than providing the DC block on the center of the coax. There is a significantly different EMI/EMC impact for breaking the shield than breaking the center conductor. Might not be an issue for a GPS Active Antenna, but it's something to think about (we have some coaxial DC blocks at work that break both, but also apparently make mighty fine slot radiators at 30 GHz). And, don't forget that these are cost sensitive devices. 4 diodes and their installation and board real estate costs money, as would the extra couple capacitors for the DC blocks, etc. There is certain to be one diode on the hot lead anyway... engineers get nervous when they leave out stuff like that.. No.. I doubt there's a diode in the hot lead. These sorts of devices is a low cost device designed to be hooked up a specific piece of equipment. They'd trust that they designed the equipment it's connected to is of the correct polarity. Hook it up backwards and it fries. There's also the forward voltage drop issue.. One or two diodes in series is a significant power consumption bump in a system where you're evaluated on microjoules/fix. so adding a bridge would eliminate that diode. A quick check of Mouser gives me a cost difference (qty 1000) of one dime for the added bridge and capacitor... 12 cents if there was no diode in the original circuit. Circuit boards on devices like hockey puck antennas tend to be sparsely populated, so I don't think it would make any difference there. There's a non zero cost at the manufacturer for inventory costs and incoming inspection, as well as the additional cost for the extra components in the pick and place machine, and the reduced machine throughput. This all adds up. For a lot of circuits, the other costs could be 10-20x the actual parts cost, especially for inexpensive passives like resistors and capacitors. It would be worth the cost if the antenna was meant to be a universal device, but probably not if it was intended to be used on only one receiver. Which is why universal devices cost more.. (or, don't exist.. The price we pay for leveraging off consumer commodity pricing is that what WE want isn't made...it's something that's almost what we want.) Jim ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP 5335a opt 40 addendum
Magnus Danielson wrote: Dear Norm, Norman J McSweyn wrote: Magnus, Thanks for the enlightenment! I modified the driver that NI has on their site. Works. Have been manually setting the trigger levels on the front panel. Now know how to use the -40 to do it. Great! Happy to help! I'll further modify the driver in the AM. The manual I have doesn't have programming example 13. I haven't looked in detail, but I *think* the HP5335A manual on the HP site is the same as I have, and then you should have all the details you need. Magnus, Unfortunatly, the manual on Agilent's site is the one that I have, without the -40 addendum. I take it that the instrument will trigger automatically when the conditions are met? Indeed it does. I'm comparing the 1pps output from an M12+t to the divided down 10MHz out from a Thunderbolt. Next hurdle is to do something with the collected data. Way to go! You should learn to calculate Allan deviation and friends. Not to hard. You should learn to estimate drift rate and subtract that from measurements, since that is often ignored and the drift rate will form a lower floor for longer measurement runs. This is an error which is either canceled by locking or by software. Data is time stamped and in a text file. One file is the TI data from the 5335a, the other is part of the @@Hn (with the sawtooth correction) message from the M12+T. In the interest of ensuring that I have a useful data set, I need to find a way to use Excel to check that no seconds have been skipped. Then post process the TI measurement to reflect the 1pps sawtooth. The next steps are a mystery. I drive locomotives for a living. This is a hobby!! Have been playing with math for a while now, so it's not a black art! Didier has a few pages on measurements and one with tvb's explanation of Allan deviation. This will be today's reading!!! Translating this into an Excel spreadsheet is the next hurdle. Comparing the two devices (Thunderbolt to M12+T) is rather banal. It's like comparing two types of apples together. Not much difference. However, it's a steep learning curve to get to this point. Any pointers are welcome! Thanks, Norm n3ykf Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Oncore, Trimble Antennae
Lux, James P wrote: ... But not so trivial to provide the DC blocks in the ground side of the coax. The LNA is almost certainly some MMIC with RF ground==Vss Not any worse than providing the DC block on the center of the coax. There is a significantly different EMI/EMC impact for breaking the shield than breaking the center conductor. Might not be an issue for a GPS Active Antenna, but it's something to think about (we have some coaxial DC blocks at work that break both, but also apparently make mighty fine slot radiators at 30 GHz). Yes, but we are talking about a GPS hockey puck, not a 30GHz device. At these low frequencies, life is pretty easy. A little careful pc layout work, and you could do the DC block using the board almost entirely. And, don't forget that these are cost sensitive devices. 4 diodes and their installation and board real estate costs money, as would the extra couple capacitors for the DC blocks, etc. There is certain to be one diode on the hot lead anyway... engineers get nervous when they leave out stuff like that.. No.. I doubt there's a diode in the hot lead. These sorts of devices is a low cost device designed to be hooked up a specific piece of equipment. They'd trust that they designed the equipment it's connected to is of the correct polarity. Hook it up backwards and it fries. There's also the forward voltage drop issue.. One or two diodes in series is a significant power consumption bump in a system where you're evaluated on microjoules/fix. Not a watch, but a hockey puck antenna. The receivers that use hockey puck antennas are typically powered by a car's electrical system. They have to ditch 8V anyway, might as well lose some of it in a pair of diodes. so adding a bridge would eliminate that diode. A quick check of Mouser gives me a cost difference (qty 1000) of one dime for the added bridge and capacitor... 12 cents if there was no diode in the original circuit. Circuit boards on devices like hockey puck antennas tend to be sparsely populated, so I don't think it would make any difference there. There's a non zero cost at the manufacturer for inventory costs and incoming inspection, as well as the additional cost for the extra components in the pick and place machine, and the reduced machine throughput. This all adds up. For a lot of circuits, the other costs could be 10-20x the actual parts cost, especially for inexpensive passives like resistors and capacitors. Agreed. It would be worth the cost if the antenna was meant to be a universal device, but probably not if it was intended to be used on only one receiver. Which is why universal devices cost more.. (or, don't exist.. The price we pay for leveraging off consumer commodity pricing is that what WE want isn't made...it's something that's almost what we want.) Yep! Almost always true. The hockey puck antennas, were sold as a product by themselves, and there were a lot of receivers that used them. I think motorola and others thought of them as universal devices but I also think they thought of them as disposable, so it isn't clear that they cared if you burned one out by misapplication. I have a spare around the shop somewhere. If it isn't too destructive, I think I'll open it up and take a look. -Chuck Harris ___ time-nuts mailing 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] Oncore, Trimble Antennae
Lux, James P wrote: That's really kind of funny, in 29 years as an engineer, I have never had an accountant talk to me about design decisions. I tell them what it will cost, and they say ok. Lucky you... Not luck, but a conscious decision to stay out of consumer electronics. I could see the writing on the wall 30 years ago. Consumer electronics design and manufacturing in the US is just biding its time, waiting for the last guy out to switch off the lights. I am glad I stayed out of it. In the consumer electronics world, they do BOM scrubs and whole multi work-year analyses to figure out how to remove a few square millimeters of PWB, or even better, what's the trade between some jumpers and a single sided board and a double sided board, and do we really need plated through holes. I worked on a project where they spent about 4-6 work months to eliminate a couple capacitors at a nickle each. When you're making 10,000,000 units, that nickle per cap turns into a million bucks, many times the few tens of $K the engineering time cost. In the space electronics world, you'd do the same BOM scrub, but there the idea is to eliminate parts that might fail, or add mass, or require testing (each different part in the part list adds something like $5K-$10K from a testing, inventory control, etc. standpoint) There is nothing wrong with having to justify your design. That is what the design review process is all about. I have never had to justify a design to an accountant. I have never met the accountant that could design circuitry. Kind of like an engineer framing houses... no, wait, I do that. -Chuck Harris ___ time-nuts mailing 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] LPRO lamp decay
Maybe this could be of interest. I have an LPRO continuously running since ending last January. Lamp volt was 7.92V. As of October 22 (today, 9 months later) the voltage is 7.7V. The voltage dropped by 0.22V. The VCXO Volt was 6.7V, and now is 6.8V. It is powered at 24V, and the temperature at the heatsinked baseplate is 40 °C. I see one could expect many years of operation from such surplus units. 73, Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. I have an LPRO rubidium oscillator. I mounted it on a heat sink with fins and placed it in an insulated box. A small (40mm) fan is switched to control the base-plate temperature at 40*C + or - 0.05*. As it warms up to the control point the oscillator control voltage changes by 1 volt, so the oscillator control voltage is very temperature sensitive. I do not think it will age beyond its control range. I hope that the temperature control will improve the frequency accuracy by a large ratio. cheers, Neville Michie On 23/10/2008, at 8:02 AM, iovane@@inwind..it wrote: I would be very pleased to know when (date and time) anybody out there happened to record jumps in frequency of crystals. I have stable (e-07) tuning forks which happen to jump too, and I don't understand why, even having under control temperature and air pressure. Sometimes they return to their prior frequency with another jump, and this could happen even days later, sometimes they jump and then recover smoothly the prior frequency in a short time (such as one hour). I have no idea whether any correlations would exist between crystals and tuning forks jumps, regarding the causes that could trigger metastability, and hence I would have a look at crystal data in order to improve the base for future speculation. Thanks in advance. Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
I'm not quite sure what the question is here, but when we made 10811 oscillators at HP, jumps happened. Some crystals were better than others, but no crystal was immune from jumps. With good quality crystals, you might be able to put an upper bound on the magnitude of jumps, like 10-9, but not on the time between jumps. I also noticed that there didn't seem to be any correlation between jump activity and stability between jumps. You could have an oscillator with really low aging, say a few parts in 1E11 per day that looked really good for quite a while, but then the frequency jumps. After you've controlled everything you can about the crystal process, the electronics, the oven and the environment, you are still left with jumps. If you want no jumps, go to an atomic standard like rubidium. There are mechanisms that can cause jumps in rubidium standards as well, but good rubidium standards don't jump. Rick Karlquist N6RK [EMAIL PROTECTED] wrote: I would be very pleased to know when (date and time) anybody out there happened to record jumps in frequency of crystals. I have stable (e-07) tuning forks which happen to jump too, and I don't understand why, even having under control temperature and air pressure. Sometimes they return to their prior frequency with another jump, and this could happen even days later, sometimes they jump and then recover smoothly the prior frequency in a short time (such as one hour). I have no idea whether any correlations would exist between crystals and tuning forks jumps, regarding the causes that could trigger metastability, and hence I would have a look at crystal data in order to improve the base for future speculation. Thanks in advance. Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
Are you sure it is the tuning fork and not the reference for your counter? - 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, October 22, 2008 5:02 PM To: time-nuts Subject: [time-nuts] Question on crystal jumps I would be very pleased to know when (date and time) anybody out there happened to record jumps in frequency of crystals. I have stable (e-07) tuning forks which happen to jump too, and I don't understand why, even having under control temperature and air pressure. Sometimes they return to their prior frequency with another jump, and this could happen even days later, sometimes they jump and then recover smoothly the prior frequency in a short time (such as one hour). I have no idea whether any correlations would exist between crystals and tuning forks jumps, regarding the causes that could trigger metastability, and hence I would have a look at crystal data in order to improve the base for future speculation. Thanks in advance. Antonio I8IOV ___ time-nuts mailing 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] OT: connector identification
Might be a SMB. Björn Gabrielsson wrote: Hi List, I have a coax connector that I would like to identify. Se attached picture. To the left is a female TNC for reference. The unknown male is attached to the cable. Unknown female to the upper left as part of a T adapter. It looks kind of a smaller version of TNC. It is slighly larger than SMA. Female diameter is 5/16, whereas TNC is 7/16 and SMA is 4/16 - according to my simple measurement. Anyone recognizing this connector? thanks, Björn ___ time-nuts mailing 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] Question on crystal jumps
Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. Thanks, I was missing this info. I have an LPRO rubidium oscillator. I mounted it on a heat sink with fins and placed it in an insulated box. A small (40mm) fan is switched to control the base-plate temperature at 40*C + or - 0.05*. As it warms up to the control point the oscillator control voltage changes by 1 volt, so the oscillator control voltage is very temperature sensitive. I do not think it will age beyond its control range. In this case, I believe it is a design spec. I experience the same with several LPRO's. The crystal inside LPRO has an heatsink itself, which would improve the thermal coupling between it and the rest of the assembly. I think it is expected to run at its nominal frequency after the warm-up of the whole unit. It may have beed designed accordingly. 73, Antonio I8IOV ___ time-nuts mailing 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] OT: connector identification
Brian Kirby wrote: Might be a SMB. Björn Gabrielsson wrote: Hi List, I have a coax connector that I would like to identify. Se attached picture. To the left is a female TNC for reference. The unknown male is attached to the cable. Unknown female to the upper left as part of a T adapter. It looks kind of a smaller version of TNC. It is slighly larger than SMA. Female diameter is 5/16, whereas TNC is 7/16 and SMA is 4/16 - according to my simple measurement. Anyone recognizing this connector? thanks, Björn Not an SMB as mated SMB connectors don't have a threaded retainer and are smaller than an SMA. SMC is the threaded version and has same internal diameter as SMB. 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.
Re: [time-nuts] Question on crystal jumps
Hi Rick I'm not quite sure what the question is here The question is: may anybody tell me (date and time) when a crystal jumped? (a sample response could be: my crystal jumped on January 22, 2006 12:25 UT). I would like to map in time as many jumps as possible. I hope someone in the list has a log of his jumps. Thanks and 73, Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
Are you sure it is the tuning fork and not the reference for your counter? - 73 - Mike Hi Mike, the tuning fork jumps were in the order of e-7, while the references were a HP 10811 and a Racal Opt 04E both in the range of e-10. Thanks and 73, ANtonio ___ time-nuts mailing 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] Question on crystal jumps
Neville, Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. I have an interest in this. May you point me to any references? 73, Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
College freshman physics (in 1955) included a story about the probability of all atoms in a chalk board eraser moving the same way at the same time, causing it to jump off the board. The incredibly small probability of that happening was what kept solid matter apparently inert. I would not discourage you from looking for an intergalactic cause of jumps, but I think the laws of probability are quite sound. Perhaps you could prove that by describing the randomness of the jumps in many crystals in many places. Bill Hawkins ___ time-nuts mailing 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] Question on crystal jumps
At 06:48 PM 10/22/2008, Bill Hawkins wrote... I would not discourage you from looking for an intergalactic cause of jumps, but I think the laws of probability are quite sound. OTOH, perhaps Yoda is correct - I feel a disturbance in the force. :-) ___ time-nuts mailing 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] Question on crystal jumps
Hi: A possible explanation is cosmic rays. The actual particle that gets to the surface of the Earth is so energetic that it would take a very thick lead shield to stop them. The Earth has enough mass that they can not go all the way through. http://en.wikipedia.org/wiki/Muon So a test would be to stack a few crystals very close together (it's just plain geometry) and monitor their frequency to look for coincident jumps. Have Fun, Brooke Clarke http://www.prc68.com/P/Prod.html Products I make and sell http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam Ron Smith wrote: Hello Antonio, A.W.Ladner and C.R.Stoner in their book Short Wave Wireless Communication describe a phenomenon called stepping, which may be the same effect as the jumps you are investigating. The book is quite old, 4th edition published in 1942 by Chapman and Hall, and refers (on page 321) to stepping in X- and Y-cut crystals, which may not be common these days, but perhaps crystals of all cuts are affected to some degree. The text says the curve of frequency against plate thickness does not give a straight line, but has discontinuities in it. These discontinuities they call stepping points and are a result of edge vibrations coinciding with sub-multiple frequencies of the wanted thickness vibration mode. The degree of coupling between the wanted and unwanted modes varies with crystal dimension. If there is zero coupling, the stepping points should not affect the main oscillation. But perhaps even the smallest change in dimension can cause it to cross one of these discontinuities and jump to and fro? I suspect that crystal sensitivity to stepping or jumping may be correlated with its temperature coefficient, although there are other factors (including gravitational) that influence frequency of oscillation at very small levels. Antonio, these frequency jumps are not a phenomenon I have come across myself, so I have nothing to log, but I am interested in what you discover. Wouldn't it be fascinating if you discovered a global trigger to many simultaneous frequency steps? The book reference is a bit old I'm afraid - things have moved on since 1942. Good luck. Ron Smith G3SVW - Original Message - From: [EMAIL PROTECTED] To: time-nuts time-nuts@febo.com Sent: Wednesday, October 22, 2008 11:06 PM Subject: Re: [time-nuts] Question on crystal jumps Hi Rick I'm not quite sure what the question is here The question is: may anybody tell me (date and time) when a crystal jumped? (a sample response could be: my crystal jumped on January 22, 2006 12:25 UT). I would like to map in time as many jumps as possible. I hope someone in the list has a log of his jumps. Thanks and 73, Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
Hi, In : Accurate Clock Pendulums by Robert Matthys (2004) Oxford University Press ISBN 0198529716, Pp264 In Chapter 8 , The Allen variance and the rms time error, on page 38 he writes: Figure 8.1 shows another characteristic of pendulum clocks - the clock will run relatively smoothly at one rate , and then after 3 - 6 months it will suddenly jump to a new rate as shown if Fig 8.1. He goes on to say that this is part of a random walk process. I hope that is of some help. Neville MIchie On 23/10/2008, at 9:34 AM, iovane@@inwind..it wrote: Neville, Hi Antonio, precise pendulum clocks also suffer rate jumps, the process of rate jumping seems to be common to most time counting systems. I have an interest in this. May you point me to any references? 73, Antonio I8IOV ___ time-nuts mailing 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] OT: connector identification
Hi Björn: The Pasternack hard copy catalog, or the on line version: http://www.pasternack.com/pdf/catalog/ConnectorIdentifier.pdf are a handy reference to identify coax connectors. It's handy to have a pair of digital vernier calipers with switchable metric and inch displays to get the key dimensions needed. Have Fun, Brooke Clarke http://www.prc68.com/P/Prod.html Products I make and sell http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam Björn Gabrielsson wrote: Hi List, I have a coax connector that I would like to identify. Se attached picture. To the left is a female TNC for reference. The unknown male is attached to the cable. Unknown female to the upper left as part of a T adapter. It looks kind of a smaller version of TNC. It is slighly larger than SMA. Female diameter is 5/16, whereas TNC is 7/16 and SMA is 4/16 - according to my simple measurement. Anyone recognizing this connector? thanks, Björn ___ time-nuts mailing 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] OT: connector identification
There IS a mini-TNC as I recall. My ancient (80s vintage) cellphone had such a thing on the antenna. There's also something referred to as a mini-UHF (presumably a small PL-259), but the amphenol catalog pitures show the serrated top of the female, and yours are smooth. The thread was 3/8 -24 threads/inch James Lux, P.E. Task Manager, SOMD Software Defined Radios Flight Communications Systems Section Jet Propulsion Laboratory 4800 Oak Grove Drive, Mail Stop 161-213 Pasadena, CA, 91109 +1(818)354-2075 phone +1(818)393-6875 fax -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Björn Gabrielsson Sent: Wednesday, October 22, 2008 2:23 PM To: time-nuts Subject: [time-nuts] OT: connector identification Hi List, I have a coax connector that I would like to identify. Se attached picture. To the left is a female TNC for reference. The unknown male is attached to the cable. Unknown female to the upper left as part of a T adapter. It looks kind of a smaller version of TNC. It is slighly larger than SMA. Female diameter is 5/16, whereas TNC is 7/16 and SMA is 4/16 - according to my simple measurement. Anyone recognizing this connector? thanks, Björn ___ time-nuts mailing 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] Question on crystal jumps
Do rubidium standards use an OCXO? Bob Q. - Original Message - From: Rick Karlquist [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, October 22, 2008 2:23 PM Subject: Re: [time-nuts] Question on crystal jumps I'm not quite sure what the question is here, but when we made 10811 oscillators at HP, jumps happened. Some crystals were better than others, but no crystal was immune from jumps. With good quality crystals, you might be able to put an upper bound on the magnitude of jumps, like 10-9, but not on the time between jumps. I also noticed that there didn't seem to be any correlation between jump activity and stability between jumps. You could have an oscillator with really low aging, say a few parts in 1E11 per day that looked really good for quite a while, but then the frequency jumps. After you've controlled everything you can about the crystal process, the electronics, the oven and the environment, you are still left with jumps. If you want no jumps, go to an atomic standard like rubidium. There are mechanisms that can cause jumps in rubidium standards as well, but good rubidium standards don't jump. Rick Karlquist N6RK [EMAIL PROTECTED] wrote: I would be very pleased to know when (date and time) anybody out there happened to record jumps in frequency of crystals. I have stable (e-07) tuning forks which happen to jump too, and I don't understand why, even having under control temperature and air pressure. Sometimes they return to their prior frequency with another jump, and this could happen even days later, sometimes they jump and then recover smoothly the prior frequency in a short time (such as one hour). I have no idea whether any correlations would exist between crystals and tuning forks jumps, regarding the causes that could trigger metastability, and hence I would have a look at crystal data in order to improve the base for future speculation. Thanks in advance. Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
This is a very interesting thread. When I retired from Western Kentucky University in 2001 I was given a very expensive mantel clock. Seven day wind up with a balance wheel. I have had a lot of fun regulating it over the last 7 years. Right now I have it holding within 5 seconds a month but past experience has shown that it won't hold indefinitely. Since the balance wheel is also an oscillator I assume it will undergo these frequency jumps. Regards. Max. K 4 O D S. Email: [EMAIL PROTECTED] Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, [EMAIL PROTECTED] - Original Message - From: Bob Q [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, October 22, 2008 8:22 PM Subject: Re: [time-nuts] Question on crystal jumps Do rubidium standards use an OCXO? Bob Q. - Original Message - From: Rick Karlquist [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Wednesday, October 22, 2008 2:23 PM Subject: Re: [time-nuts] Question on crystal jumps I'm not quite sure what the question is here, but when we made 10811 oscillators at HP, jumps happened. Some crystals were better than others, but no crystal was immune from jumps. With good quality crystals, you might be able to put an upper bound on the magnitude of jumps, like 10-9, but not on the time between jumps. I also noticed that there didn't seem to be any correlation between jump activity and stability between jumps. You could have an oscillator with really low aging, say a few parts in 1E11 per day that looked really good for quite a while, but then the frequency jumps. After you've controlled everything you can about the crystal process, the electronics, the oven and the environment, you are still left with jumps. If you want no jumps, go to an atomic standard like rubidium. There are mechanisms that can cause jumps in rubidium standards as well, but good rubidium standards don't jump. Rick Karlquist N6RK [EMAIL PROTECTED] wrote: I would be very pleased to know when (date and time) anybody out there happened to record jumps in frequency of crystals. I have stable (e-07) tuning forks which happen to jump too, and I don't understand why, even having under control temperature and air pressure. Sometimes they return to their prior frequency with another jump, and this could happen even days later, sometimes they jump and then recover smoothly the prior frequency in a short time (such as one hour). I have no idea whether any correlations would exist between crystals and tuning forks jumps, regarding the causes that could trigger metastability, and hence I would have a look at crystal data in order to improve the base for future speculation. Thanks in advance. Antonio I8IOV ___ time-nuts mailing 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] Question on crystal jumps
Mike S wrote: At 06:48 PM 10/22/2008, Bill Hawkins wrote... I would not discourage you from looking for an intergalactic cause of jumps, but I think the laws of probability are quite sound. OTOH, perhaps Yoda is correct - I feel a disturbance in the force. :-) Could be like Schroedinger's Cat. If you guys would stop watching your clocks so closely maybe they'd stop jumping. ___ time-nuts mailing 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] Question on crystal jumps
This is a very interesting thread. When I retired from Western Kentucky University in 2001 I was given a very expensive mantel clock. Seven day wind up with a balance wheel. I have had a lot of fun regulating it over the last 7 years. Right now I have it holding within 5 seconds a month but past experience has shown that it won't hold indefinitely. Since the balance wheel is also an oscillator I assume it will undergo these frequency jumps. How small a jump could you notice? Unless you have it in a temperature controlled box, I'd expect any tiny jumps would be lost in the temperature wobbles. Can you see temperature wobbles? Can you see any correlations with the phase of the moon? (gravity, tides) -- 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.
