Re: [time-nuts] Random Walk Noise experiment
ehydra wrote: I think the confusion is now perfect: http://www.mikrocontroller.net/topic/207061#2059725 Let Google translate it from german to your language. Does the difference come from voltage vs. power spectrum? Yes, integrating the power spectrum of white noise produces flicker noise whilst integrating it twice produces random walk noise. In practice integrating the power spectrum requires implementing fractional order (=1/2) integration of the signal ( voltage or current) and single integration of the signal is equivalent to double integration of the power spectrum. Bruce Magnus Danielson schrieb: On 12/02/11 21:02, Bruce Griffiths wrote: Flicker noise is not the same as random walk noise, the spectra differ. Using an AC coupled generator (eg a sound card) filters out the low frequency content. Zeners and transistors (biased at low current) can be used to generate flicker noise directly at least for low frequencies where it dominates. Generating random walk noise is more difficult, integrating white noise is one technique that can be used (at least in principle). Of course... *head-slapp* white noise has a flat power spectrum flicker noise has a power spectrum of slope f^-1 random walk noise has a power spectrum of slope f^-2 For random walk you need to do integration. If you do it in analogue, care in low-frequency cut-off comes in and below it you will have white noise. For digital it's a trivial, but you may end up with digital wrap-around but doing a low-frequency leakage you avoid it and end up with the same situation as in the analogue domain. So expect there to be a frequency limit for it if synthesized. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FRSc RB lamp experiment
Paul, On 13/02/11 04:27, paul swed wrote: Well pretty good news The lamp voltage went from 1.83 volts a dead bulb to* 8.9 volts a new bulb*. By adjusting the oscillator I can get to 9.6 volts but I know the the oscillator will not start correctly at 82 Mhz its happy at 92 Mhz. This is good news, for the level of re-assembly you where at. The lamp is in the ball-park now... Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Random Walk Noise experiment
On 13/02/11 07:11, ehydra wrote: I think the confusion is now perfect: http://www.mikrocontroller.net/topic/207061#2059725 Let Google translate it from german to your language. Does the difference come from voltage vs. power spectrum? Yes. When you integrate you get a f^-1 slope in voltage spectrum and f^-2 in power spectrum. f^-1/2 in voltage spectrum is... uhm... hard. So we either use a flicker source (as I proposed) or an approximation filter. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Supply
Dear Bert and all, maybe I missed it, but how can a linear regulator filter out transients from a switched PSU? The cited LT1764A has less than 30dB Suppression at 100 kHz getting worse for higher frequencies.Even the famous 7805 had only 50 dB suppression. For going to a real clean PSU, I would expect some old-school filtering and screening should be fine.. or am I wrong? A classic 50/60 Hz all linear PSU has a bad efficiency, but very little high frequency spurs to care about. For my current project (GPSDO with double oven HP10811), I will only use those.. even the classic LED 7-segment display I am planning to use will not use multiplexed mode but quasi-static (1 Hz update rate only). Regards, Achim ___ time-nuts mailing 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] Thunderbolt Supply
Achim of course I am using Filters, among others the wide band inductors Radio Conrad offers. Contact me direct and I will send you sketches of what I do, including GPSDO with 10811. Where are you located? Bert In a message dated 2/13/2011 8:44:56 A.M. Eastern Standard Time, avoll...@physik.uzh.ch writes: Dear Bert and all, maybe I missed it, but how can a linear regulator filter out transients from a switched PSU? The cited LT1764A has less than 30dB Suppression at 100 kHz getting worse for higher frequencies.Even the famous 7805 had only 50 dB suppression. For going to a real clean PSU, I would expect some old-school filtering and screening should be fine.. or am I wrong? A classic 50/60 Hz all linear PSU has a bad efficiency, but very little high frequency spurs to care about. For my current project (GPSDO with double oven HP10811), I will only use those.. even the classic LED 7-segment display I am planning to use will not use multiplexed mode but quasi-static (1 Hz update rate only). Regards, Achim ___ time-nuts mailing 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] Laser ranging time-stamping equipment
Hi! While doing a random google-search for a HP5370B page (I was lazy), I crashed into a set of pages relating to laser ranging. I think it could be enlightening as it has a number of time-stamping equipments we usually do not discuss, but it also provides some comments on best use and limitations of various equipment. http://ilrs.gsfc.nasa.gov/engineering_technology/timing/tof_devices/manufacture_spec/ Honeywell HTSI is one of those: http://cddis.gsfc.nasa.gov/lw15/docs/papers/High-Speed%20Enhancement%20to%20HTSI%20Event%20Timer%20Systems.pdf Another is the Latvia University devices. I tough I would toss the torch in. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Efratom 10Mhz frequency standard from Fluke.l
David, I I told yesterday it was too late for writing an explanation. Here it is. I bought one of these units around last June, my intended use was to distribute the 10 MHz from my Rb oscillator to be used as the reference for various synthesizers and counters in my home lab. I didn't put it to use yet, but I made some test with the gadget and this is what I found: - The power supply should be some 15V, not 12 as announced. There is a 3 pin 12 volt linear regulator7812CT which needs some overhead to work, and a DC-DC converter to generate +5V which is specified at 15V input and in fact it doesn't work well below it. - The 10 MHz oscillator is a EFRATOM 105243-003 and there is a jumper for selecting this oscillator or an external 10 MHz input. The circuit has a 8.7 V regulator built with a 431 programmable zener with an opamp and a multiturn pot which is accessible from outside for adjusting the oscillator frequency. There is also a hole in the oscillator for adjusting the frequency. - The oscillator output is squared with an unknown comparator and fed to the inputs of what seems to be a 74ACT244DW which 8 outputs drive the output connectors through coupling networks. The PCB has provisions for 8 SMA output connectors, with only 4 populated. I bought a bunch of identical connectors from other supplier and I'll install them when I'll put the unit into operation, I'll only have to drill 4 holes for them in the case and solder the output networks, nothing critical. - Currently the unit has 2 output networks configured for square wave output (just a 50 ohm resistor in series) and the 2 remaining for sine wave output. In this case the network consist on a 50 Ohm series resistor, a pi LC filter a and a series capacitor. According to the silkscreen labels it was the manufacturer intended configuration. It is easy to transform any output for square or sine because the parts are smd but of reasonable size. - I don't have the means to measure the jitter or phase noise introduced by this schema, but any expert here could give his opinion about it. The ovenized oscillator on my unit doesn't perform very well in terms of aging or time to stabilize, it is worse that my other oscillators ( ) from the same source, I compared them with my Rb and maybe I didn't waited enough days, but anyway the others 2 were very stable after 1 week and this one not. -. I don't know the exact parts used for the comparator and the buffer because the tops have been filed. When I reverse engineered the schematic I offered it to fluke.l, in the believe that it could be useful for his customers but his answer suggested that he had filed the IDs in the fear of other Chinese competition could copy his modifications and refused to give me the parts numbers. If you want more info don't hesitate to ask for it. Regards, Ignacio, EB4APL El 12/02/2011 22:03, Dave M wrote: Does anyone have any experience or knowledge of the Efratom Multiplexed output 10Mhz frequency standard from Fluke.l on EBay (item 290329156915)? I wonder if it could be used as a distribution amp, but no details about output impedance, output current capability, etc. He indicates that the output voltage is 1.8 - 2.3 volts (doesn't say if it's open circuit or terminated). From the images on the listing, looks like he didn't terminate any of the lines to the counters or scopes. Thanks David dgminala at mediacombb dot net ___ time-nuts mailing 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] FRSc RB lamp experiment
Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. So I pulled the fet gate Q2 to ground through a 1 K ohm resistor setting the lamp to 24 volts. After ignition just let it float taking the lamp voltage to 17 Volts. The lamp, after ignition is 10 volts when its oven is still cool and has dropped in brightness. This is normal for the warm up period. Still at 8.5044 volts after the lamp oven gets to 177 degrees. VCO correction voltage is 6.023v. As I recall, this is mid range on the voltage. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. By the way I purchased the heat gun from a supplier thats on amazon.com. Its the NTE or ECG HG300d for $19.95. Two heat ranges 250 degree c and 350 degree c. Small and easy to handle. I used the low range and adjusted the height of the lamp to the heat gun tip approximately 4 distance to get 300 degrees F. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Regards Paul WB8TSL On Sun, Feb 13, 2011 at 8:12 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Paul, On 13/02/11 04:27, paul swed wrote: Well pretty good news The lamp voltage went from 1.83 volts a dead bulb to* 8.9 volts a new bulb*. By adjusting the oscillator I can get to 9.6 volts but I know the the oscillator will not start correctly at 82 Mhz its happy at 92 Mhz. This is good news, for the level of re-assembly you where at. The lamp is in the ball-park now... 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] FRSc RB lamp experiment
Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] FRSc RB lamp experiment
Startup circuit looks like a bad op amp used as a comparator. U1 section a. This is a LM 158. I have a LM 148 on hand suspect they are different in temperature quality. So will look it up and see. This is a common op amp so if the 148 does not work for some reason any numbers of more modern ones will. Accept one issue its a T08 can. What pin was 8? ;-) Regards On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. 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] FRSc RB lamp experiment
paul swed wrote: Startup circuit looks like a bad op amp used as a comparator. U1 section a. This is a LM 158. I have a LM 148 on hand suspect they are different in temperature quality. So will look it up and see. This is a common op amp so if the 148 does not work for some reason any numbers of more modern ones will. Accept one issue its a T08 can. What pin was 8? ;-) Regards The LM148 (quad 741) and LM158 (dual opamp) have different input common mode ranges, that of the LM158 extends to the negative supply it is also rated for a large input differential voltage. LM158 pin 8 is the positive supply pin. Bruce On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Looking for 5372 boards
Willem Programmer PRO GQ-4X Geraldo, Just curious which EPROM programmer you purchased? Joe -- Geraldo Lino de Campos gera...@decampos.net ___ time-nuts mailing 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] Looking for 5372 boards
Thanks. Would love to hear how it works. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Geraldo Lino de Campos Sent: Sunday, February 13, 2011 1:03 PM To: time-nuts@febo.com Subject: Re: [time-nuts] Looking for 5372 boards Willem Programmer PRO GQ-4X Geraldo, Just curious which EPROM programmer you purchased? Joe -- Geraldo Lino de Campos gera...@decampos.net ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Efratom 10Mhz frequency standard from Fluke.l
Many thanks for the input, Ignacio. I sent an email to Fluke.l (Bob) asking for more details, but haven't received a response yet. I doubt that he will reveal much more info about it than what is in the Ebay description. Your info certainly goes a long way to answer my concerns. In view of all this, I'll go with a TAPR solution or an Extron video DA. Cheers, Dave M From: EB4APL eb4...@cembreros.jazztel.es Subject: Re: [time-nuts] Efratom 10Mhz frequency standard from Fluke.l David, I I told yesterday it was too late for writing an explanation. Here it is. I bought one of these units around last June, my intended use was to distribute the 10 MHz from my Rb oscillator to be used as the reference for various synthesizers and counters in my home lab. I didn't put it to use yet, but I made some test with the gadget and this is what I found: - The power supply should be some 15V, not 12 as announced. There is a 3 pin 12 volt linear regulator7812CT which needs some overhead to work, and a DC-DC converter to generate +5V which is specified at 15V input and in fact it doesn't work well below it. - The 10 MHz oscillator is a EFRATOM 105243-003 and there is a jumper for selecting this oscillator or an external 10 MHz input. The circuit has a 8.7 V regulator built with a 431 programmable zener with an opamp and a multiturn pot which is accessible from outside for adjusting the oscillator frequency. There is also a hole in the oscillator for adjusting the frequency. - The oscillator output is squared with an unknown comparator and fed to the inputs of what seems to be a 74ACT244DW which 8 outputs drive the output connectors through coupling networks. The PCB has provisions for 8 SMA output connectors, with only 4 populated. I bought a bunch of identical connectors from other supplier and I'll install them when I'll put the unit into operation, I'll only have to drill 4 holes for them in the case and solder the output networks, nothing critical. - Currently the unit has 2 output networks configured for square wave output (just a 50 ohm resistor in series) and the 2 remaining for sine wave output. In this case the network consist on a 50 Ohm series resistor, a pi LC filter a and a series capacitor. According to the silkscreen labels it was the manufacturer intended configuration. It is easy to transform any output for square or sine because the parts are smd but of reasonable size. - I don't have the means to measure the jitter or phase noise introduced by this schema, but any expert here could give his opinion about it. The ovenized oscillator on my unit doesn't perform very well in terms of aging or time to stabilize, it is worse that my other oscillators ( ) from the same source, I compared them with my Rb and maybe I didn't waited enough days, but anyway the others 2 were very stable after 1 week and this one not. -. I don't know the exact parts used for the comparator and the buffer because the tops have been filed. When I reverse engineered the schematic I offered it to fluke.l, in the believe that it could be useful for his customers but his answer suggested that he had filed the IDs in the fear of other Chinese competition could copy his modifications and refused to give me the parts numbers. If you want more info don't hesitate to ask for it. Regards, Ignacio, EB4APL El 12/02/2011 22:03, Dave M wrote: Does anyone have any experience or knowledge of the Efratom Multiplexed output 10Mhz frequency standard from Fluke.l on EBay (item 290329156915)? I wonder if it could be used as a distribution amp, but no details about output impedance, output current capability, etc. He indicates that the output voltage is 1.8 - 2.3 volts (doesn't say if it's open circuit or terminated). From the images on the listing, looks like he didn't terminate any of the lines to the counters or scopes. Thanks David dgminala at mediacombb dot net ___ time-nuts mailing 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] FRSc RB lamp experiment
Who would have thought a seriously leaky cap c7 on the input of U1a pin 3. Roughly 10K ohm. System is running at 1.6 x10^11. See if it hangs in there. Lamp is actually going higher in voltage at 8.2 V. All in all a good experiment. Regards Paul. On Sun, Feb 13, 2011 at 1:46 PM, paul swed paulsw...@gmail.com wrote: Startup circuit looks like a bad op amp used as a comparator. U1 section a. This is a LM 158. I have a LM 148 on hand suspect they are different in temperature quality. So will look it up and see. This is a common op amp so if the 148 does not work for some reason any numbers of more modern ones will. Accept one issue its a T08 can. What pin was 8? ;-) Regards On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. 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] FRSc RB lamp experiment
Thanks Bruce turned out to be C7 leaky. I actually used a LM358 dip with wires kind of a ugly bug. Then realzed that really was not the issue. It was c7. I do not have any lm158s can or dip. Pretty sure they would be hard to come by these days also. Something to look for at hamfests this year. Regards Paul. On Sun, Feb 13, 2011 at 2:01 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: paul swed wrote: Startup circuit looks like a bad op amp used as a comparator. U1 section a. This is a LM 158. I have a LM 148 on hand suspect they are different in temperature quality. So will look it up and see. This is a common op amp so if the 148 does not work for some reason any numbers of more modern ones will. Accept one issue its a T08 can. What pin was 8? ;-) Regards The LM148 (quad 741) and LM158 (dual opamp) have different input common mode ranges, that of the LM158 extends to the negative supply it is also rated for a large input differential voltage. LM158 pin 8 is the positive supply pin. Bruce On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] FRSc RB lamp experiment
I do not have any lm158s can or dip. Pretty sure they would be hard to come by these days also. Digikey has stock on everything but the ceramic DIP. They do have it in TO-99/TO-5. -- 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] FRSc RB lamp experiment
At 17:50 -0500 13-02-2011, paul swed wrote: I do not have any lm158s can or dip. Pretty sure they would be hard to come by these days also. Should you need one, they are in stock @ Digi-Key, Newark/Farnell and several other distributors. JDB. [courtesy of http://findchips.com/ ] -- If you think the problem is bad now, just wait until we've solved it. -- Arthur Kasspe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Efratom 10Mhz frequency standard from Fluke.l
Hi, Since David asked about levels, I connected the unit and got these figures: Sine output: 2.8 VPP when loaded with 50 Ohm, internal capacitor coupled Square wave: 0 to +2.5 V loaded with 50 Ohm. There are other two internal SMA connectors with TTL levels: one is the inverted comparator output and the other is from one of the buffer outputs. Initial current is .35 A at startup, decreasing to .16 A in about 10 minutes, when the oven reached its working temperature. If you want other measurements, pictures, etc., let me know. Regards, Ignacio El 13/02/2011 18:48, EB4APL wrote: David, I I told yesterday it was too late for writing an explanation. Here it is. I bought one of these units around last June, my intended use was to distribute the 10 MHz from my Rb oscillator to be used as the reference for various synthesizers and counters in my home lab. I didn't put it to use yet, but I made some test with the gadget and this is what I found: - The power supply should be some 15V, not 12 as announced. There is a 3 pin 12 volt linear regulator7812CT which needs some overhead to work, and a DC-DC converter to generate +5V which is specified at 15V input and in fact it doesn't work well below it. - The 10 MHz oscillator is a EFRATOM 105243-003 and there is a jumper for selecting this oscillator or an external 10 MHz input. The circuit has a 8.7 V regulator built with a 431 programmable zener with an opamp and a multiturn pot which is accessible from outside for adjusting the oscillator frequency. There is also a hole in the oscillator for adjusting the frequency. - The oscillator output is squared with an unknown comparator and fed to the inputs of what seems to be a 74ACT244DW which 8 outputs drive the output connectors through coupling networks. The PCB has provisions for 8 SMA output connectors, with only 4 populated. I bought a bunch of identical connectors from other supplier and I'll install them when I'll put the unit into operation, I'll only have to drill 4 holes for them in the case and solder the output networks, nothing critical. - Currently the unit has 2 output networks configured for square wave output (just a 50 ohm resistor in series) and the 2 remaining for sine wave output. In this case the network consist on a 50 Ohm series resistor, a pi LC filter a and a series capacitor. According to the silkscreen labels it was the manufacturer intended configuration. It is easy to transform any output for square or sine because the parts are smd but of reasonable size. - I don't have the means to measure the jitter or phase noise introduced by this schema, but any expert here could give his opinion about it. The ovenized oscillator on my unit doesn't perform very well in terms of aging or time to stabilize, it is worse that my other oscillators ( ) from the same source, I compared them with my Rb and maybe I didn't waited enough days, but anyway the others 2 were very stable after 1 week and this one not. -. I don't know the exact parts used for the comparator and the buffer because the tops have been filed. When I reverse engineered the schematic I offered it to fluke.l, in the believe that it could be useful for his customers but his answer suggested that he had filed the IDs in the fear of other Chinese competition could copy his modifications and refused to give me the parts numbers. If you want more info don't hesitate to ask for it. Regards, Ignacio, EB4APL El 12/02/2011 22:03, Dave M wrote: Does anyone have any experience or knowledge of the Efratom Multiplexed output 10Mhz frequency standard from Fluke.l on EBay (item 290329156915)? I wonder if it could be used as a distribution amp, but no details about output impedance, output current capability, etc. He indicates that the output voltage is 1.8 - 2.3 volts (doesn't say if it's open circuit or terminated). From the images on the listing, looks like he didn't terminate any of the lines to the counters or scopes. Thanks David dgminala at mediacombb dot net ___ time-nuts mailing 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] FRSc RB lamp experiment
The LM 158 and LM358 are the same part, just different screening levels and packaging. For commercial applications at normal temperatures, the LM358 is fine. Didier KO4BB Sent from my Verizon Wireless BlackBerry -Original Message- From: paul swed paulsw...@gmail.com Sender: time-nuts-boun...@febo.com Date: Sun, 13 Feb 2011 17:50:18 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] FRSc RB lamp experiment Thanks Bruce turned out to be C7 leaky. I actually used a LM358 dip with wires kind of a ugly bug. Then realzed that really was not the issue. It was c7. I do not have any lm158s can or dip. Pretty sure they would be hard to come by these days also. Something to look for at hamfests this year. Regards Paul. On Sun, Feb 13, 2011 at 2:01 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: paul swed wrote: Startup circuit looks like a bad op amp used as a comparator. U1 section a. This is a LM 158. I have a LM 148 on hand suspect they are different in temperature quality. So will look it up and see. This is a common op amp so if the 148 does not work for some reason any numbers of more modern ones will. Accept one issue its a T08 can. What pin was 8? ;-) Regards The LM148 (quad 741) and LM158 (dual opamp) have different input common mode ranges, that of the LM158 extends to the negative supply it is also rated for a large input differential voltage. LM158 pin 8 is the positive supply pin. Bruce On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Dear Paul, On 13/02/11 18:50, paul swed wrote: Magnus it indeed does look very good. I have re-assembled the various boards and the system locked up as normal after the warm up period. I do indeed have a failure in the lamp control startup crkt. My RS does not have a startup circuit, so I can't help on that particular detail. I'm sure you will debug it yourself. The reference after warm up and adjusting the c field is down in the 1x10-11 area. Anyhow I adjusted the c field and the systems not fully assembled nor has it really been stabilized long enough. Was simply curious so I do not think this is really a very accurate assessment. Especially since this is time-nuts territory. At least it proves that you are up and running at least, modulus quirks. So next steps is to let the unit cook in or maybe I will further assemble it and troubleshoot the startup crkt. Add the unlock counter. (A pedometer and opto coupler) and let the system run for a long while perhaps a week or so to see what really happens. Sounds like a plan. Thanks for your guidance and help Magnus. Who would have thought there was a recovery technique for FRS-c RB references. Happy to help. Happy to learn of your progress! Happy to hear I contribute. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Why do crystals go bad?
Group, Jim Garland on the boatanch...@theporch.com list asked about crystals: A 22.5MHz crystal (HC-5 case) in my homebrew receiver, built about forty years ago, no longer oscillates. It seems to be purely an age-related problem. It is in a standard solid state circuit which bandswitches six crystals, and the other five work just fine. I wonder what causes a crystal to stop working, and whether it is possible to repair them? I've repaired dead 100kHz calibrator crystals, and hamband crystals in FT-243 cases, by cleaning off the brass pressure plates, but am not sure if one can do this on thin high crystals. As I recall, the metal electrodes are evaporated onto the sides of the element. 73, Jim W8ZR One of the replies was: Broken families, drugs, drink... the normal, I suppose. John K5MO Scott Robinson asked: Receiver crystals aren't getting beaten up by high power, but something has killed a lot of them in my R-390A and Drake R-4A. Curiously yours, Scott And Roy Morgan asked: I have a 1960's frequency standard from a Nike site: the Sulzer Oscillator and would like to find tech into on it. Any help appreciated. 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] Why do crystals go bad?
Two authors come to mind regarding crystal oscillators: Eric Vittoz and Marvin Ferking. Eric Vittoz is the more modern of the two. His writings tend towards long term stability of crystal oscillators. Basically, most designs put too much energy into the crystal, which he claims wears it out. I'd had to dig up his papers, but my recollection is the failures were soft (error in frequency) rather than hard (total failure). Ferking covers temperature stability and crystal pulling. I haven't dealt with crystal manufacturers in a long time, but my recollection is the crystal is tuned by metal deposition. As you deposit metal on the crystal, the frequency lowers. Possibly today they laser trim, i.e. remove metal. Anyway, I don't think opening up the case and fiddling with the innards is a good idea. In the dark ages, when I took a class in wafer fabrication, we would sense the amount of metal sputtered on the wafer by measuring the frequency shift of a crystal in the chamber. As you sputtered metal, the crystal frequency would get lower. Ferking's DSP book is supposedly the bible in software defined radios. Back to crystal manufacturers, these companies tend to be pretty small. when I was working on video chip designs, it was no problem talking to the CEO or VP engineering. I think it is a capital intensive rather than labor intensive business. They have a few gurus doing product design and that's about it. In the dark ages, these guys were the easiest to deal with for technical info: http://www.crovencrystals.com/ They have an impressive list of projects that they worked on: http://www.crovencrystals.com/croven_pdf/heritageprograms.pdf On 2/13/2011 7:26 PM, Bill Hawkins wrote: Group, Jim Garland on the boatanch...@theporch.com list asked about crystals: A 22.5MHz crystal (HC-5 case) in my homebrew receiver, built about forty years ago, no longer oscillates. It seems to be purely an age-related problem. It is in a standard solid state circuit which bandswitches six crystals, and the other five work just fine. I wonder what causes a crystal to stop working, and whether it is possible to repair them? I've repaired dead 100kHz calibrator crystals, and hamband crystals in FT-243 cases, by cleaning off the brass pressure plates, but am not sure if one can do this on thin high crystals. As I recall, the metal electrodes are evaporated onto the sides of the element. 73, Jim W8ZR One of the replies was: Broken families, drugs, drink... the normal, I suppose. John K5MO Scott Robinson asked: Receiver crystals aren't getting beaten up by high power, but something has killed a lot of them in my R-390A and Drake R-4A. Curiously yours, Scott And Roy Morgan asked: I have a 1960's frequency standard from a Nike site: the Sulzer Oscillator and would like to find tech into on it. Any help appreciated. 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. ___ time-nuts mailing 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] Why do crystals go bad?
On 14/02/11 04:26, Bill Hawkins wrote: Group, Jim Garland on the boatanch...@theporch.com list asked about crystals: A 22.5MHz crystal (HC-5 case) in my homebrew receiver, built about forty years ago, no longer oscillates. It seems to be purely an age-related problem. It is in a standard solid state circuit which bandswitches six crystals, and the other five work just fine. I wonder what causes a crystal to stop working, and whether it is possible to repair them? I've repaired dead 100kHz calibrator crystals, and hamband crystals in FT-243 cases, by cleaning off the brass pressure plates, but am not sure if one can do this on thin high crystals. As I recall, the metal electrodes are evaporated onto the sides of the element. 73, Jim W8ZR Any help appreciated. On the any help level: Aging usually makes crystals go adrift in frequency. Other parameters may also shift, especially if the DC connectivity is lost due to oxidation or so. I think it is likely that this is what happend and all of a sudden the loop conditions does not support oscillation (i.e. gain 1 when phase shift is 0 degrees modulus 360 degrees). There might be hacks to be added to get the loop oscillating again and there might be hacks to the crystal assembly, but swapping the crystal is probably a good remedy in this case. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Supply
I have a Power-One switching power supply that puts out +/- 15 Volts in addition to +5 Volts. I was planning to add a pair of 7812/7912 voltage regulators to provide the required +/- 12 Volts to the Thunderbolt. I would welcome any suggestions to improvements in this very basic design, including additional filtering, etc. Please post or email. BTW, has anyone considered using one of the many DC-to-DC PSUs that are available for powering mobile PCs from +12 Volts? They appear to be ideal for powering the Thunderbird from almost any DC power source, including a 12 Volt battery. -- Flemming Larsen, OZ6OI/KB6ADS oz...@yahoo.dk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
