Re: [time-nuts] Loran, GPS, Lightning, Timing
Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Amen to that! It's also turned from reporting to preaching-political! I always wanted to build the amateur scientist stuff, but there were always the lines with arrows off the figure to power supply. Wonder if that's why I have hell boxes full of old power supplies:-) Probably a darned good thing I didn't build the x-ray tube! Don -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation)
Hi, I fail to see what the benefit is of removing this unless a better temp compensation scheme is used. It is not likely to interfer with the external loop as it reduces the midterm noise that is systematic. It does add some higher rate noise but that is quantization errors of the systematics it reduces. I like to see measurement that support the claim and I am skeptic. As I see it you give the external loop more systematic noise to dampen and the tighter loop you make the more you will expose. Cheers, Magnus div Originalmeddelande /divdivFrån: Scott Newell newell+timen...@n5tnl.com /divdivDatum:28-06-2014 03:50 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation) /divdiv /divBert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using the '5680 inside a control loop, it's likely to conflict. By removing the resistor, that channel of the 12 bit ADC will be tied to ground through an existing 2.21k resistor. The unit will see a constant 0 counts from the ADC and assume it's really cold. I modified one unit and monitored it for a few hours over a range of temps, running it nice and hot with no heatsink, then blasting it with a fan and placing it on an ice-cold heatsink. I observed no change in the DDS tuning words. It's a really easy mod--remove four screws, set aside the insulator sheet, and apply your hot leucotome/soldering iron. I've also found a simple mod to replace the temperature signal with the output of the unused trimpot. This allows you to simulate any temperature you want. If there's any interest, I'll set up a test and monitor the DDS tuning words as the unit's firmware tries to adjust to the fake temp signal. -- newell N5TNL ___ time-nuts mailing 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] DIY FE-5680A lobotomy (disable temp compensation)
Because the 96K attachment needs moderator approval I am sending it again without attachment. It is the one I posted before and shows clearly the frequency jumps. So here is the rest of it. Magnus Sorry but I disagree with your statement. First and foremost we have to accept that these devices are not intended for time nuts (metrology). Already my first 1985 FRK monitors the cell current and adjusts the C field accordingly. The HP 5065 does not since it is not intended for the same market, it relies on its temperature control of the total A12 assembly. A closer look at FE specs you will notice the following statement including frequency over or undershoot at any fast or slow temperature slew rate. How do you think they do it. In the case of units that have a DDS in the control loop they do it with the DDS. How else do you explain the attached plot. Again my apologies for not remembering who posted it. I noticed the jumps and mentioned them when I first took a look at the 5680 I did use temperature control in a crude way using what I call the Bang Bang fan control on an ATT FRS heatsink. My YSI did not register any changes but the 5680 noticed and was visible using my Tracor 527 E. The 5680 is not a unit that we will use it turned in to a distraction but we did the controller for time nuts. Our focus when it comes to temperature control is on the FRK that is why Juerg who focused on the 5680 only uses a heat sink. Working out of a basement that is next to a garage data in the winter looks a lot more stable than now. We monitor the tuning word which has a resolution of 6.8 E-13 and when you see no change over long time periods in January and changes now exceeding E-12 now to start asking why. The differences are garage door is open more often and the sun shines part of the time directly in to his basement lab. When the loop is in the long time constant mode to take advantage of the GPS accuracy resolution which increases with time, jumps by the 5680 DDS are no help. It all depends what ultimate accuracy time nuts want out of the 5680. A good fan control along with a fixed setting the temperature ADC input used for frequency control will yield best results. Work by time nuts will help we are not going to do it. The reason is we are totally tied up with work on using the FE 405 B. I stumbled by accident on to it and bought some for testing. Initial tests show for me unbelievable performance specially when it comes to ADEV. It is perfect for GPSDO applications since it is all digital control with a step resolution of 6 e-15. How ever it is also not all perfect since I did detected jumps that I could not explain. Since our testing capabilities are limited I did make Tom aware of the unit and he has now caught the bug. http://leapsecond.com/pages/fe405/ . We think we have traced the problem to again frequency control using oven current have disabled it and hope to have better data to prove that the 3 E-12 jumps are due to the current monitor. Stay tuned. Hope it does not change the ADEV. Not many of you have OCXO's with that low ADEV. We are also using the controller for this device and results look very promising. That is why we call it the Universal Controller. In the future it will control many other devices. But for now please those of you that have the equpment and the expertize focus on the FE 5680 A to make it a viable low cost house reference for a large # of time nuts. Bert Kehren In a message dated 6/28/2014 3:21:48 A.M. Eastern Daylight Time, mag...@rubidium.dyndns.org writes: Hi, I fail to see what the benefit is of removing this unless a better temp compensation scheme is used. It is not likely to interfer with the external loop as it reduces the midterm noise that is systematic. It does add some higher rate noise but that is quantization errors of the systematics it reduces. I like to see measurement that support the claim and I am skeptic. As I see it you give the external loop more systematic noise to dampen and the tighter loop you make the more you will expose. Cheers, Magnus div Originalmeddelande /divdivFrån: Scott Newell newell+timen...@n5tnl.com /divdivDatum:28-06-2014 03:50 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation) /divdiv /divBert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using
Re: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation)
Hi Scott, I reviewed the material at the N5TNL site and it leaves me wondering. There are at least three different and separate temperature controlling areas inside the FEI-5680. One of which has cannot be messed with due to the fact that it is inherent in its design. That would be the posistor (i.e., a PTC resistor) that is attached to the 60 MHz crystal that acts as a general heater. The other two locations are on the physics package itself. One for the lamp area and the other is for the cavity chamber. SO. The lamp area, I surmise is rather simple as it does not require tight temperature control like the cavity chamber area would need. The lamp area just needs a temperature to change and maintain the Rb into a gas form. The cavity chamber area is way more sensitive to temperature as it affects the pressure, frequency and stability of the Rb in the cavity. I suspect that the control mechanism for this area to be more complicated. The block diagram, while pretty general in nature, does show that the system (i.e., internal computer) has an A/D monitoring 4 inputs. Three of the A/D channels are observing system data and the fourth is temperature. What it does not tell us is what temperature or system data it is monitoring. SO... Here is the rub, the only temperature that is truly critical is the cavity temperature. BUT, the system computer does not really control that temperature, except possibly monitor it, as indicated on the block diagram. Thus the real question is, is that the temperature being referred to in the monitoring process ? In other words have you traced out the connections to see what is driving the pin you think is the temperature input ? I would think that the temperature reading would have a steadily climbing curve from the application of power to some steady state (relative) value. However, the curve that you selected as temperature seems to rise and become steady (relative) some period of time after application of power and seems associated with the unit going into a lock condition. OR, so you indicate on some of your graphs. The next big question is have you monitored the frequency and its stability, externally, to observe what effects are taking place when you disable this input to the A/D ? I realize Bert is trying to take FEI to a tighter level, but I wonder if it would be better to add thermal mass to buffer external ambient changes rather than screw with the internal control mechanisms. Particularly seeing as how we have no knowledge of the what the internal firmware is doing. By thermal mass I mean on all sides of the unit. The only way to really achieve that would be make a stirred oil bath container with the FEI suspended in the center of said bath. That sounds complicated and messy but may be easier than it appears. An appropriate container would be: http://www.worldkitchen.com/en/snapware-food-storage/1098437.html It is made out of polypropylene and can handle at least 130 degrees C and it holds just under two and half gallons of oil. Light mineral oil runs around $15 a gallon, so two gallons would be the right amount leaving a little room at the top. Wicking is a problem with wires and cables but using connectors attached to the lid solves that problem by breaking the wicking surface. The final question is how much, if any, external oil cooling would be necessary. That would have to be experimentally determined. The mineral oil, by the way, has a higher flash point then the container and is electrically NON-conductive. Food for thought, BillWB6BNQ Scott Newell wrote: Bert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using the '5680 inside a control loop, it's likely to conflict. By removing the resistor, that channel of the 12 bit ADC will be tied to ground through an existing 2.21k resistor. The unit will see a constant 0 counts from the ADC and assume it's really cold. I modified one unit and monitored it for a few hours over a range of temps, running it nice and hot with no heatsink, then blasting it with a fan and placing it on an ice-cold heatsink. I observed no change in the DDS tuning words. It's a really easy mod--remove four screws, set aside the insulator sheet, and apply your hot leucotome/soldering iron. I've also found a simple mod to replace the temperature signal with the output of the unused trimpot. This allows you to simulate any
Re: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation)
Hi Most of these lightweight Rb’s do the same thing. They watch the oven current on one or the other section and try to guess the external temperature. Based on that guess they do a simple temperature correction on the unit. The older analog units feed a DC signal into the EFC. The newer digital units feed a signal into the DDS. In both cases (analog and digital), the ADEV of the units can be improved by disabling this “feature”. That of course assumes you are at a constant (as in very constant) abient temperature. In the case of the analog part, it’s the noise on the heater current that gets you. In the case of the digital approach, it’s the tuning granularity of the DDS that messes things up (and possibly heater current noise as well). How constant is “very constant”? That depends on the Rb you have. A good bet is that your device runs better than 2 to 4 ppb over a 100C range without the compensation turned on. That gives you 20 to 40 ppt per degree C. To hit 1 ppt you would need to control the device to better than 0.05 C. If you simply want to hit the 0.1 ppb temperature spec, then you only need a two degree control. If you look at the temperature compensation data words (ddd steps), some Rb’s in a batch are much better than others, so there is no easy way to be sure of the results ahead of time. Bob On Jun 28, 2014, at 3:21 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi, I fail to see what the benefit is of removing this unless a better temp compensation scheme is used. It is not likely to interfer with the external loop as it reduces the midterm noise that is systematic. It does add some higher rate noise but that is quantization errors of the systematics it reduces. I like to see measurement that support the claim and I am skeptic. As I see it you give the external loop more systematic noise to dampen and the tighter loop you make the more you will expose. Cheers, Magnus div Originalmeddelande /divdivFrån: Scott Newell newell+timen...@n5tnl.com /divdivDatum:28-06-2014 03:50 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation) /divdiv /divBert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using the '5680 inside a control loop, it's likely to conflict. By removing the resistor, that channel of the 12 bit ADC will be tied to ground through an existing 2.21k resistor. The unit will see a constant 0 counts from the ADC and assume it's really cold. I modified one unit and monitored it for a few hours over a range of temps, running it nice and hot with no heatsink, then blasting it with a fan and placing it on an ice-cold heatsink. I observed no change in the DDS tuning words. It's a really easy mod--remove four screws, set aside the insulator sheet, and apply your hot leucotome/soldering iron. I've also found a simple mod to replace the temperature signal with the output of the unused trimpot. This allows you to simulate any temperature you want. If there's any interest, I'll set up a test and monitor the DDS tuning words as the unit's firmware tries to adjust to the fake temp signal. -- newell N5TNL ___ time-nuts mailing 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] DIY FE-5680A lobotomy (disable temp compensation)
On Sat, Jun 28, 2014 at 4:32 AM, wb6bnq wb6...@cox.net wrote: wicking surface. The final question is how much, if any, external oil cooling would be necessary. That would have to be experimentally determined. The mineral oil, by the way, has a higher flash point then the container and is electrically NON-conductive. But it does have a dielectric constant different from air. How much effect would it have at microwave frequencies? Also, what would its effect be on the optical path from the Rb lamp and through the Rb cell? -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
QST lightning radar. But what a mess you get with google and every lightning and radar TV station in the US. Oh well if your replacing TVs every few years whats a few more opamps? Now how does a poor man build something for what started this whole thread? Time for me to hop off this thread. Regards Paul WB8TSL On Sat, Jun 28, 2014 at 2:37 AM, Don Latham d...@montana.com wrote: Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Amen to that! It's also turned from reporting to preaching-political! I always wanted to build the amateur scientist stuff, but there were always the lines with arrows off the figure to power supply. Wonder if that's why I have hell boxes full of old power supplies:-) Probably a darned good thing I didn't build the x-ray tube! Don -- The power of accurate observation is commonly called cynicism by those who have not got it. -George Bernard Shaw Dr. Don Latham AJ7LL Six Mile Systems LLC 17850 Six Mile Road Huson, MT, 59846 mail: POBox 404 Frenchtown MT 59834-0404 VOX 406-626-4304 Skype: buffler2 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation)
Thanks Bob for putting it in perspective, 0.05 C is very doable, looks like it is also used in some OCXO's. Bert Kehren PS on a related subject I just pulled PROCEEDINGS OF THE ANNUAL SYMPOSIUM ON FREQUENCY CONLTROL ATLANTIC CITY in the late 70's did attend a few because of my involvement in GPS but then did not understand half of it and now want to check what I have learned since. Very interesting reading. In a message dated 6/28/2014 9:36:32 A.M. Eastern Daylight Time, kb...@n1k.org writes: Hi Most of these lightweight Rb’s do the same thing. They watch the oven current on one or the other section and try to guess the external temperature. Based on that guess they do a simple temperature correction on the unit. The older analog units feed a DC signal into the EFC. The newer digital units feed a signal into the DDS. In both cases (analog and digital), the ADEV of the units can be improved by disabling this “feature”. That of course assumes you are at a constant (as in very constant) abient temperature. In the case of the analog part, it ’s the noise on the heater current that gets you. In the case of the digital approach, it’s the tuning granularity of the DDS that messes things up (and possibly heater current noise as well). How constant is “very constant”? That depends on the Rb you have. A good bet is that your device runs better than 2 to 4 ppb over a 100C range without the compensation turned on. That gives you 20 to 40 ppt per degree C. To hit 1 ppt you would need to control the device to better than 0.05 C. If you simply want to hit the 0.1 ppb temperature spec, then you only need a two degree control. If you look at the temperature compensation data words (ddd steps), some Rb’s in a batch are much better than others, so there is no easy way to be sure of the results ahead of time. Bob On Jun 28, 2014, at 3:21 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: Hi, I fail to see what the benefit is of removing this unless a better temp compensation scheme is used. It is not likely to interfer with the external loop as it reduces the midterm noise that is systematic. It does add some higher rate noise but that is quantization errors of the systematics it reduces. I like to see measurement that support the claim and I am skeptic. As I see it you give the external loop more systematic noise to dampen and the tighter loop you make the more you will expose. Cheers, Magnus div Originalmeddelande /divdivFrån: Scott Newell newell+timen...@n5tnl.com /divdivDatum:28-06-2014 03:50 (GMT+01:00) /divdivTill: time-nuts@febo.com /divdivRubrik: [time-nuts] DIY FE-5680A lobotomy (disable temp compensation) /divdiv /divBert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using the '5680 inside a control loop, it's likely to conflict. By removing the resistor, that channel of the 12 bit ADC will be tied to ground through an existing 2.21k resistor. The unit will see a constant 0 counts from the ADC and assume it's really cold. I modified one unit and monitored it for a few hours over a range of temps, running it nice and hot with no heatsink, then blasting it with a fan and placing it on an ice-cold heatsink. I observed no change in the DDS tuning words. It's a really easy mod--remove four screws, set aside the insulator sheet, and apply your hot leucotome/soldering iron. I've also found a simple mod to replace the temperature signal with the output of the unused trimpot. This allows you to simulate any temperature you want. If there's any interest, I'll set up a test and monitor the DDS tuning words as the unit's firmware tries to adjust to the fake temp signal. -- newell N5TNL ___ time-nuts mailing 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] DIY FE-5680A lobotomy (disable temp compensation)
At 04:32 AM 6/28/2014, wb6bnq wrote: monitoring process ? In other words have you traced out the connections to see what is driving the pin you think is the temperature input ? No. I've only traced back from the ADC input to the voltage divider. The next big question is have you monitored the frequency and its stability, externally, to observe what effects are taking place when you disable this input to the A/D ? I have not. That sounds complicated and messy but may be easier than it appears. An appropriate container would be: It does sound messy. I don't think I'm willing to dunk one of my units. -- newell N5TNL ___ time-nuts mailing 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] DIY FE-5680A lobotomy (disable temp compensation)
I can only answer some of your questions. The tuning word is modified by the temperature but if it came back to the same oven current it will again have the same tuning word to the DDS. Since we have not fount a temperature sensor they most likely use oven current that Bob mentioned. If you do not plan to use it with a controller I would not recommend disconnecting it but if you have good temperature control you should not see a difference. The controller can not selectively enable or disable the temperature sensor and it would not make sense since the controller has no info as to temperature and enabling the frequency control do to temperature would most likely cause a frequency step.. The answer is use a laptop heat pipe it will do a great job when portable and takes little power, Just received some more recharable lithium 12 V 9.8 A batteries. Light weight and low cost Bert Kehren In a message dated 6/27/2014 11:04:31 P.M. Eastern Daylight Time, albertson.ch...@gmail.com writes: So the FE5680A will actually change the DDS tuning word based on an internal temperature sensor? I could see why you might ant to disable this or maybe not depending on how it works. Does the FE5680 first read the user programmed word, apply a delta then write it back or does it ignore user settings. I can't believe it would overwrite a user programmed running word. But this also means there is a sensitive temperature sensor inside the FE5680. Is there any way to read this sensor via the serial port? What software are you using to communicate with the FE5680. I'd like to try doe experiments. 1) see if we can take advantage some how of the existence of the temp sensor and 2) possibly use the analog input (a faked temp sensor) to control the FE5680. The problem with disconnecting the temperature sensor is much worse performance when the GPS is not available in hold over mode. GPS rarely fails but I'm sure some people disconnect the GPS to use the Rb as a portable frequency reference. It would be good if it were temperature compensated while in holdover. One experiment comes to mind: If the resister is removed, can there GPSDO controller selectively enable and disable temperature compensation? What software are you using to support your testing? On Fri, Jun 27, 2014 at 6:50 PM, Scott Newell newell+timen...@n5tnl.com wrote: Bert asked me to send an update on the FE-5680 tempco mod progress. It appears that the FE-5680A temperature signal (or maybe it's really a current sense signal?) can be disabled by removing a single 10k 0805 surface mount resistor. Using Elio Corbolante's terrific high-res scans, I've noted the resistor location: http://www.n5tnl.com/time/fe-5680a/lobotomy.png Why would you want to disable temperature compensation? As we've seen, the unit's firmware will adjust the DDS frequency as the temperature signal changes. If you're using the '5680 inside a control loop, it's likely to conflict. By removing the resistor, that channel of the 12 bit ADC will be tied to ground through an existing 2.21k resistor. The unit will see a constant 0 counts from the ADC and assume it's really cold. I modified one unit and monitored it for a few hours over a range of temps, running it nice and hot with no heatsink, then blasting it with a fan and placing it on an ice-cold heatsink. I observed no change in the DDS tuning words. It's a really easy mod--remove four screws, set aside the insulator sheet, and apply your hot leucotome/soldering iron. I've also found a simple mod to replace the temperature signal with the output of the unused trimpot. This allows you to simulate any temperature you want. If there's any interest, I'll set up a test and monitor the DDS tuning words as the unit's firmware tries to adjust to the fake temp signal. -- newell N5TNL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] DIY FE-5680A lobotomy (disable temp compensation)
Will someone beside us use heat pipe. Would love to have an impendent input. What does it take to get a test going. Scott has done a lot of work, how about some one else step up to the plate. There are a lot of time nuts out there with the 5680A,many for the first time will have a very good reference and some of our experts with proper equipment can make a big difference. Bert Kehren In a message dated 6/28/2014 12:20:12 P.M. Eastern Daylight Time, newell+timen...@n5tnl.com writes: At 04:32 AM 6/28/2014, wb6bnq wrote: monitoring process ? In other words have you traced out the connections to see what is driving the pin you think is the temperature input ? No. I've only traced back from the ADC input to the voltage divider. The next big question is have you monitored the frequency and its stability, externally, to observe what effects are taking place when you disable this input to the A/D ? I have not. That sounds complicated and messy but may be easier than it appears. An appropriate container would be: It does sound messy. I don't think I'm willing to dunk one of my units. -- newell N5TNL ___ time-nuts mailing 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] GPSDO standard interface?
Hidden on the backplane of the Nortel (trimble) units is a SCPI interface known as the Serial Interface to CDMA system It is RS485 standard but I usually tap into the TTL I/O of the transceiver chip. This is the standard SCPI interface. E D C B A 1 +24/-48Vdc +24/-48Vdc +24/-48Vdc +24/-48Vdc +24/-48Vdc 4 +24/-48VRTN +24/-48VRTN +24/-48VRTN +24/-48VRTN +24/-48VRTN 5 Frame ground Frame ground Frame ground Frame ground Frame ground 15 GPSTM Tx Data_- GPSTM Tx Data_+ Digital ground GPSTM Rx Data_- GPSTM Rx Data_+ 19 CM_1 Even_Sec_+ CM_1 Even_Sec_- Digital ground CM_2 Even_Sec_+ CM_2 Even_Sec_- Zpack commonly used connections [cid:image009.png@01CF92F8.B74C7660] [cid:image010.png@01CF92F8.B74C7660] Typical RS484 interface Commands Command/Response Format Value/Range 1 Time code query C: Get Time Code Info. Query R: Time Code Information String Character 13 Character n ptime:tcode? x* 2 Preset receiver command C: Reset GPS Command R: none Character 12 syst:preset 3 Receiver identification query C: Identification Query R: Manufacturer and revision information Character 6 Character n *idn? x*,x*,x*,x*[,x*,x*,x*] 4 Set Receiver Position C: Specify Position Command R: none Character n gps:position a,n*,n*,n*.n*,a,n*,n*,nn.n*,n* .n* 5 Get Receiver Position C: Position Query R: Location Character 14 Character n gps:position? A,n*,n*,n.n*E[+- ]n*,A,n*,n*,n.n*E[+- ]n*,n.n*E[+-]n* 6 Set antenna delay C: Antenna delay in seconds R: none Character 27 gps:ref:adelay .n 7 Get antenna delay C: Query antenna delay R: Antenna Delay in seconds Character 16 Character n gps:ref:adelay? n.n*E[+-]n* 8 GPS survey command C: Survey mode command R: none Character 25 or Character 20 gps:pos:survey[:stat] once 9 Set manual holdover mode C: Holdover Initiate Command R: none Character 15 rosc:hold:init 10 Set manual holdover recov- ery C: Recover from manual hold- over R: none Character 19 rosc:hold:rec:init 11 Holdover duration query C: Holdover Duration Query R: Holdover Duration in Sec- onds Character 15 Character n rosc:hold:dur? n.n*E[+-]n*,0 | 1 12 List of Satellites being tracked C: Tracked Satellites Query R: List of satellites ID's Character 18 Character n gps:sat:tracking? n*,n*,n*,n*,n*,n*,n*,n* 13 List of predicted Satellites In View C: Satellites in View Query R: List of predicted Satellites in view Character 18 Character n gps:sat:vis:pred? n*,n*,n*,n*,n*,n*,n*,n* 14 Immediate Synchronization Command C: Synchronize GPS system R: none Character 15 sync:immediate 15 System Language Query C: System mode query R: System Mode String Character 11 Character 7 syst:lang? PRIMARY | INSTALL 16 Frequency Figure of Merit query C: Freq. Figure of Merit Query R: Frequency figure of merit Character 11 Character n sync:ffom? n* 17 Survey progress query C: Survey Progress Query R: Percent of Survey com- pleted. Character 25 Integer gps:pos:survey:progress? 0 to 100 decimal 18 Clear error queue command C: Clear Error Command R: none Character 5 none *cls 19 Log data query C: Read Log Entry Query R: Log Entry Data Character 15 Character n diag:log:read? [n] x* 20 Clear log entries command C: Clear log entries command R: none Character 15 diag:log:clear 21 Log entries query C: Query log entries R: Number of entries in log. Character 16 Character n diag:log:count? n* 22 Operation status register query C: Query operation status reg- ister R: Status register Character 28 Character n status:operation:condition? n* 23 Life time Counter query C: Get Lifetime Count Query R: Total Powered-On Time Character 21 Character n diag:lifetime:count? n* 24 Return Last Response query C: Request last response Com- mand R: Last Response string Character 16 Character n diag:query:resp? x* 25 Port initialization C: Initialize port R: none Character 1 \r\n 26 Set GPS Satellite Elevation Mask Angle C: Elevation Mask Angle Query R: none Character 21 gps:sat:trac:emangle n* 27 Get GPS Satellite Elevation Mask Angle C: Get Elev. Mask Angle Query R: Elevation mask angle in degrees Character 22 Byte gps:sat:trac:emangle? 0 to 89 decimal 28 Get list of Specific Satellites not Tracked. C: Get Ignored Satellites Query R: List of satellites ID's Character 21 Character n gps:sat:trac:ignore? n* 29 Set Ignored (disable track- ing) of Specific Satellites C: Set Ignored Satellites Com- mand R: none Character (21 + size of sat. list) gps:sat:trac:ignore n*,n*, ... 30 Get Included Satellites C: Get Included Satellites Query R: List of satellites ID's Character 22 Character n gps:sat:trac:include? n*, n*,... 31 Set Included for Specific Satellites C: Set Included Satellites Command R: none Character 21 (+sat. list) gps:sat:trac:include n*,n*,... 32 Set Enable LED C: Enable LED Command R: none Character 14 led:enabled 1 33
Re: [time-nuts] Loran, GPS, Lightning, Timing
There is actually a lot of information on lightening observation. If you have access to a university library. Some public libraries have on-line databases you can search too. Google is not so good at this as most of the papers are in journals where you need a subscription, or more likely a library that has a subscription. I used to own a sail boat and took an interest in lightening and red a bunch about it a few years back. You can guess why. On a boat on the ocean you are very exposed, If a storm comes you can't simply get off the water so there you are living under a 65 foot aluminum pole which is the tallest conductor for miles and miles around. So what to do about it? I looked around and the most of the answers where coming from the University of Florida. They have some good How To publications if you want to survive direct hits (to cover the sailing example) and also theory but about detection, they have a lightening observatory there are there are papers describing the instruments. They observe the normal LF but also up in VHF and even x-ray detectors. Techniques are described for determining the types of strikes (polarity) and some time they cn see plrity reversals in cloudsand cloud to cloud discharges.Once you find a few survey papers they will have a long list of citations and you can hunt down those papers. A good search phrase is *Lightning Observatory in Gainesville * I think before anyone builds any detector it might help ask what data you want. Are you wanting to simply detect that lighting is nearby so you can disconnect equipment or do you want to characterize the lightening in some way?It turns out almost always you need to know the location and this means you need to make observations from sites that are some miles apart. What a good TN application. You need to have good time so you can combine the measurements. What I learned about the boat is that I needed a VERY good conducting path from the mast to the saltwater. This was made somewhat easy on my boat because I had a 7,000 pound lead keel in contact with water (except for some paint) and the mast was keel stepped. Give the current a nice easy straight line path and it will take it and not bother you. On Sat, Jun 28, 2014 at 6:52 AM, Brian Lloyd br...@lloyd.com wrote: On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Friday, June 27, 2014 22:47 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing C. L. Stong wrote The Amateur Scientist articles in Scientific American magazine for many years, throughout the 1940s - 1960s and later period. As a child, I read these avidly and built many of the things he described. I did not know he was a ham! All The Amateur Scientist articles are available on a CD. I particularly remember building a nuclear magnetic resonance spectrometer (well, a simple one) in the late 1950s from one of his articles. Scientific American magazine today is a mere shadow of its former self, due mainly to a new publisher imported from Popular Science magazine. There is no longer an Amateur Scientist article in each issue. Larry W6FUB On 6/27/2014 9:34 PM, DaveH wrote: The only C.L. Stong (W2PFM - great call!!!) article that I could find at QST came up in an archive search: How to Cook a Ham from March 1947 A story about not having safety interlocks and getting zapped. http://p1k.arrl.org/pubs_archive/28044 You need to be an ARRL member to access the file. I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. Same for e-field. Dave KF7VNE ... -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing 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] Dephasing WWVB
Hi guys, This is my first posting. I think I’m a Time Nut, at least my friends tell me I am. I’m trying to get my old Tracor 599J phase locking receiver working again. It used to work great, but since 2012 has not worked, as you all are probably aware. I discovered an article on the web that uses an AD835 multiplier chip to square the WWVB signal which gets rid of that added phase. I built a five section synchronous filter tuned to 60 KHz to get rid of interference and its output feeds the 835 chip. This all works fine. Now I have a 120 KHz signal that’s phase free. The problem is that the 599J won’t tune that high so I have to divide this 120 KHz frequency by 2. So far I haven’t had any luck with doing this. I’ve tried to generate a pulse train from the 120 KHz signal and then use a flip-flop to divide the frequency. This does not work well. Apparently generating the pulse train picks up noise and I end up with a 60 KHz signal with fluctuating phase. Now I’m trying to get a Miller frequency divider working, but that’s not operational right now. Anyone have any other ideas? John Reed ___ time-nuts mailing 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] Magnetic Resonance Spectromater; was Re: Loran, GPS, Lightning, Timing
There's an interesting (and on topic) project in that book starting on page 335, discussing a home-made Magnetic Resonance Spectrometer. I wonder if any time-nuts have constructed such a device, and what potential accuracy it would have? Bob - AE6RV From: DaveH i...@blackmountainforge.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Saturday, June 28, 2014 1:09 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Looking for an article about frequency doubler/tripler techniques
Hi, I have spent several hours on the internet searching for an article about frequency multiplication techniques (doublers/triplers). I found it and read it about a month ago on my mobile but I didn't save the article. Now I want to read the article again but I'm not able to find it anymore. As I remember the article it contained an overview of different frequency multiplication techniques with its advantages and disadvantages. Most of the multiplier techniques in the article I'm looking for are desbribed in the links/material I have added at the bottom of this text. For me the most interesting part are the sections at the end of the article. There was a description of a frequency multiplier based on AC/ACT logic gates och possibly HC/HCT logic gates together with band pass filtering of the second and/or third harmonics. Circuit diagrams were presented and there was also a multiplier version with two multiplier stages connected together (AC/ACT/HC/HCT + filter + AC/ACT/HC/HCT + filter) to get a 2x3 or 3x2 frequency multiplier. A table with information about ouput power levels and spurious levels relative the third harmonic in different parts of the design was also presented. I think the article was of the type technical article in a free advertising based electronic magazine (RF/Microwave, Radio or general electronics). The article I found was in pdf format. I don't remember who is the author of the article. Is there anyone who with this vague description recognize the article and can help me with a link to it on the internet or possibly can send med a copy of it if it's not to be found on the internet anymore. Regards Ronny, Sweden --- Waveform Conversion, Part 1 - Sine to Square, Part 2 - Square to Sine http://www.wenzel.com/documents/waveform.html HCMOS Gates Make Frequency Multipliers http://www.wenzel.com/wp-content/uploads/hcmos.pdf Two-Diode Odd-Order Frequency Multipliers http://www.wenzel.com/documents/2diomult.html Low additive noise frequency tripler http://rfdesign.com/mag/705RFDF2.pdf Switching Diode Frequency Doublers http://www.wenzel.com/wp-content/uploads/diodedbl.pdf Choosing a Frequency Multiplier’s Waveform http://www.wenzel.com/wp-content/uploads/choose.pdf ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
I find that very puzzling. I was a subscriber to QST from some time in 1957 until into the 1960s. I didn't have a subscription to Scientific American so I couldn't have confused them. I suppose the article has been lost or somehow escaped being entered into the searchable database. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Brian Lloyd br...@lloyd.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Saturday, June 28, 2014 8:52 AM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing On Fri, Jun 27, 2014 at 11:34 PM, DaveH i...@blackmountainforge.com wrote: I also searched for Lightning and found nothing about detecting nearby strikes, only about protection. Searched from around 1980 back through 1940. There are a number of products on the market that make use of lightning detection and ranging. The BF Goodrich Stormscope is based on that. There have to be some documents around on its design. It is, in essence, a LF ADF and somehow qualifies the envelope to deduce range to the strike which it then displays to the pilot. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] Magnetic Resonance Spectromater; was Re: Loran, GPS, Lightning, Timing
Yes, that is precisely the device I built; I was in high school at the time but had been a licensed ham for 5 years and built much of my own equipment. My father had access to a machine shop and helped with the soft iron pole pieces and a few other items but I built all the electronics. And, it worked! Alas, that was a long time ago and I don't now know what happened to the spectrometer. I did not know this article reprint is in a published book. I do have all the Amateur Scientist articles on CD. Coincidentally, another local ham and also a Time Nut recently told me he built one also! Who else here did? Larry W6FUB On 6/28/2014 11:52 AM, Bob Stewart wrote: There's an interesting (and on topic) project in that book starting on page 335, discussing a home-made Magnetic Resonance Spectrometer. I wonder if any time-nuts have constructed such a device, and what potential accuracy it would have? Bob - AE6RV From: DaveH i...@blackmountainforge.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Saturday, June 28, 2014 1:09 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti st.pdf Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing 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] Dephasing WWVB
John wrote: I discovered an article on the web that uses an AD835 multiplier chip to square the WWVB signal * * *. I built a five section synchronous filter tuned to 60 KHz to get rid of interference and its output feeds the 835 chip. This all works fine. * * * the 599J won't tune that high so I have to divide this 120 KHz frequency by 2. * * * I've tried to generate a pulse train from the 120 KHz signal and then use a flip-flop to divide the frequency. This does not work well. Apparently generating the pulse train picks up noise and I end up with a 60 KHz signal with fluctuating phase. Now I'm trying to get a Miller frequency divider working Why are you trying to generate pulses, rather than just squaring (clipping) the output of the 835 in a saturated amplifier? Pulses have less energy and therefore higher noise. All you need is a signal-conditioning squarer matched to the level coming out of the 835 (see Bruce Griffith's pages at ko4bb.com for ideas, as well as the Wenzel site and any number of illustrations in Experimental Methods in RF Design -- for example, both Figures 5-46 and 4-45 show complete simple squarers with FF dividers). Even a CMOS gate biased to half-voltage should work fine. I like the NC7SZ74 Dflop for the divider. Half of a 74HC74 works fine, too. This should be the kind of thing you throw together in 15 minutes and it works first time. Best regards, Charles ___ time-nuts mailing 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] Magnetic Resonance Spectromater; was Re: Loran, GPS, Lightning, Timing
I built the Van de Graaff generator / electron accelerator with a buddy for a high-school science project. My Dad was a physicist so was able to borrow a vacuum system and not have to make that part. Lost to a guy who had done a ruby laser - this was back in 1966. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Saturday, June 28, 2014 15:18 To: Bob Stewart; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Magnetic Resonance Spectromater; was Re: Loran, GPS, Lightning, Timing Yes, that is precisely the device I built; I was in high school at the time but had been a licensed ham for 5 years and built much of my own equipment. My father had access to a machine shop and helped with the soft iron pole pieces and a few other items but I built all the electronics. And, it worked! Alas, that was a long time ago and I don't now know what happened to the spectrometer. I did not know this article reprint is in a published book. I do have all the Amateur Scientist articles on CD. Coincidentally, another local ham and also a Time Nut recently told me he built one also! Who else here did? Larry W6FUB On 6/28/2014 11:52 AM, Bob Stewart wrote: There's an interesting (and on topic) project in that book starting on page 335, discussing a home-made Magnetic Resonance Spectrometer. I wonder if any time-nuts have constructed such a device, and what potential accuracy it would have? Bob - AE6RV From: DaveH i...@blackmountainforge.com To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Saturday, June 28, 2014 1:09 PM Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing A PDF of the 1960 book can be found here: http://www.sciencemadness.org/library/books/projects_for_the_a mateur_scienti st.pdf Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing 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] wander and jitter measurements
Mike, A frequency offset is just a long term shift from nominal rate. Wander is slow variations and jitter is fast variations of phase. The separation between slow and fast is a bit arbitrary, but the 10 Hz division-line is handy as it describes different sources, where wander is the in-bandwidth noise accumulation where as jitter is usually damped pretty well by being outside of the jitter bandwidth. See ITU-T G.810, G.813, G.823-825. Cheers, Magnus On 06/27/2014 07:37 PM, bill wrote: On 6/26/2014 2:39 AM, mike cook wrote: A few dumb questions: But first a quote from the ITU ( doc G.180 ) 4.1.12 (timing) jitter: The short-term variations of the significant instants of a timing signal from their ideal positions in time (where short-term implies that these variations are of frequency greater than or equal to 10 Hz). DQ1 yes DQ2 Frequency offset would come into the Wander category except it defined differently. DQ3 No That gives my take on your q questions. Its been 23 years since I had think about jitter and wander as chairman of T1X1.3 committee Bill K7NOM 4.1.15 wander: The long-term variations of the significant instants of a digital signal from their ideal position in time (where long-term implies that these variations are of frequency less than 10 Hz). NOTE – For the purposes of this Recommendation and related Recommendations, this definition does not include wander caused by frequency offsets and drifts. DQ1. These both refer to phase variations, so with the exception of the frequency range specified, are they mathematically equivalent? DQ2. The note on wander excludes frequency offsets, but that is not specified for jitter, so do I have to include a frequency offset in jitter measurements? It seems to me that it make no sense to do so. DQ3. Can I deduce an underlying frequency offset from jitter (wander) by taking an RMS value over some window of values? regards, Mike ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] HP 8568B
Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not fou nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing 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 8568B
On 6/28/2014 6:48 PM, Hui Zhang wrote: Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not fou nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. it could happen that thes ystem reports the external reference but the time base reference oscillator doe not lock to it. To check that use the same source fo the reference and also for he input and set the span small few kHz the resolution 1/10 of the span and if you still see the freq error than the spectrum analyzer internal time base 10MHz need to readjusted since it cannot lock to the external reference, that is normal aging that instrument may be 25 years old 73 KJ6UHN Alex ___ time-nuts mailing 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 8568B
Hi Hui... The first thought is that you are tied to the resolution of the span divided by the number of displayed points -1. Try a narrower span. If you look at the absolute accuracy spec that error may be within the '66's capability. Also, I believe there is a marker counter function that will give you a more accurate reading. Another consideration is that not all of the internal LO's are locked to the 10 MHz reference. Don't panic yet :) From Tom Holmes On Jun 28, 2014, at 9:48 PM, Hui Zhang ba...@163.com wrote: Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not fo u nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing 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] HP 8568B
Hi Tommy: I used each span to do my test, they are also have frequency diffrence, the 42Hz is result of 1kHz span. I also use marker counter function, sometime I use 'peak serach' function, it will gave me a peak value, very helpful. I am thinking about the reason you and Alex talked about 'internal LO's are locked to the 10 MHz reference', I thought the internal OCXO will not join work if a EXT REF in, am I wrong? Thanks you! Hui Zhang At 2014-06-29 10:24:22, Tommy phone thol...@woh.rr.com wrote: Hi Hui... The first thought is that you are tied to the resolution of the span divided by the number of displayed points -1. Try a narrower span. If you look at the absolute accuracy spec that error may be within the '66's capability. Also, I believe there is a marker counter function that will give you a more accurate reading. Another consideration is that not all of the internal LO's are locked to the 10 MHz reference. Don't panic yet :) From Tom Holmes On Jun 28, 2014, at 9:48 PM, Hui Zhang ba...@163.com wrote: Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not f o u nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing 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] HP 8568B
Are you using the normal marker or the frequency counter marker? The counter marker should be accurate, while the frequency displayed for the normal marker position will not be. You may be able to improve the normal marker's accuracy in narrow spans if you run the shift-W self-calibration routine but it will never be as good as the counter. -- john, KE5FX -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hui Zhang Sent: Saturday, June 28, 2014 6:49 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP 8568B Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not fou nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
Back on the topic of lightening, a destructive side of lightening can occur with between-cloud strikes. Beneath a cloud with a hefty charge on it there is a counter charge, a reflection, on the earths surface. This will have the same amount of charge but in inverse polarity. When the charge in the cloud jumps to another cloud, the counter charge has to move to beneath the new cloud. This involves currents of equal magnitude to lightening strikes moving in a similar time frame. Any water pipe or buried telephone or power cable may be obliged by a potential voltage similar to a lightening strike to carry part of this current. I saw a buried phone line that had been 3 feet underground converted to an open trench 100 yards long. Any conducting cable that cuts the transient magnetic field during one of these events may be a victim. Fibre optic would seem to be the answer for protection. cheers, Neville Michie ___ time-nuts mailing 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 8568B
Certainly the point of an external reference is to replace the internal reference with one more accurate, so when external is selected the internal is out of the picture. However it is my understanding that not all of the oscillators in the signal path are locked to either reference in the '66. From Tom Holmes On Jun 28, 2014, at 10:34 PM, Hui Zhang ba...@163.com wrote: Hi Tommy: I used each span to do my test, they are also have frequency diffrence, the 42Hz is result of 1kHz span. I also use marker counter function, sometime I use 'peak serach' function, it will gave me a peak value, very helpful. I am thinking about the reason you and Alex talked about 'internal LO's are locked to the 10 MHz reference', I thought the internal OCXO will not join work if a EXT REF in, am I wrong? Thanks you! Hui Zhang At 2014-06-29 10:24:22, Tommy phone thol...@woh.rr.com wrote: Hi Hui... The first thought is that you are tied to the resolution of the span divided by the number of displayed points -1. Try a narrower span. If you look at the absolute accuracy spec that error may be within the '66's capability. Also, I believe there is a marker counter function that will give you a more accurate reading. Another consideration is that not all of the internal LO's are locked to the 10 MHz reference. Don't panic yet :) From Tom Holmes On Jun 28, 2014, at 9:48 PM, Hui Zhang ba...@163.com wrote: Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not f o u nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. 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] HP 8568B
On 6/28/2014 6:48 PM, Hui Zhang wrote: Hello all: Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz, about 88Hz diffrence. So I decide to use my Z3801A for its external reference. When I connected the cable and set the reference switch in rear paneal to EXT, the CRT displayed EXT REF, I believed it worked. But when I use it measure a nother GPSDO (Trimble ThunderBolt locked to GPS), it still have 42Hz diffrence. I am very sure both of my two GPSDO is good, if I use my HP53132A counter to compare them they will has less 1E-10 (1mHz) diffrence. And then I tie a BNC three-way connect from my Z3801A, one way to 8568B's EXT stand input, one way to the signal input in front panel, the diffrence is still 42Hz - it's 10.42MHz. I was fully confused, do I need a calibration after I used external 10Mhz stand? I read the manual again but not fou nd any infomation about how to do it. What do I do now? Anyone give me a suggestion? Any infomation will be appreciate. Hui Zhang, check the supplies from the A24 board. The oscillator +20V supply is supposed to turn off when Ext is selected. Also the series transistor for the heater supply I feel is very under rated; I mean feeding an oven heater through a 2NA sounds like a good idea? It could be that you have the internal Osc still working when Ext is selected. Also the older Ovens fitted to those are not the most reliable ones ever made. I reported on the opening up and repair of one in an 8568B of mine about six months ago but that may have been on the -hp- list, not here... Good luck! Dan ac6ao ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
Use a local solar cell and battery power supply. If it is self contained it should not attract lightning. Cheers, Neville Michie On 29/06/2014, at 1:13 PM, Hal Murray wrote: namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Loran, GPS, Lightning, Timing
Batteries or PV system. Depending on what you want to run on the remote end, you might be able to find a used solar powered shed light and use the parts. Something like this for $20: http://www.harborfreight.com/solar-shed-light-95573.html If you find a unit whose batteries are failing, you can use the parts - check thrift stores and garage sales. Down side - you will have to replace it with every lightning strike. Up side - the parts are dirt cheap and readily available. You could also use a car battery and charge it every week or so - keep two in rotation for uninterrupted operation. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Hal Murray Sent: Saturday, June 28, 2014 20:14 To: Discussion of precise time and frequency measurement Cc: hmur...@megapathdsl.net Subject: Re: [time-nuts] Loran, GPS, Lightning, Timing namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Magnetic Resonance Spectromater; was Re: Loran, GPS, Lightning, Timing
On Sat, Jun 28, 2014 at 6:55 PM, DaveH i...@blackmountainforge.com wrote: I built the Van de Graaff generator / electron accelerator with a buddy for a high-school science project. My Dad was a physicist so was able to borrow a vacuum system and not have to make that part. Lost to a guy who had done a ruby laser - this was back in 1966. I built the MRS and won the LA County Science fair and placed in the California State Science fair with it in 1968. I was 13. I also build one of the seismograph designs just for fun. I did not build the quartz reference clock design in the book but used the idea to motivate me to add a quartz reference to the 60Hz inverter I built from the ARRL handbook, using a bunch of DTL flip-flop dividers, to drive a mechanical clock with a synchronous motor. This was in 1969. So I guess that delimits the beginning of my time-nuttery. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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] Loran, GPS, Lightning, Timing
On Sat, Jun 28, 2014 at 10:13 PM, Hal Murray hmur...@megapathdsl.net wrote: namic...@gmail.com said: Fibre optic would seem to be the answer for protection. Assuming I use fibers for the data, how do I safely get power to the other end? I recommend a kite, wet string, and a Leyden jar. -- Brian Lloyd Lloyd Aviation 706 Flightline Drive Spring Branch, TX 78070 br...@lloyd.com +1.916.877.5067 ___ time-nuts mailing 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 8568B
In message 1411dfb1.542.146e54f3eac.coremail.ba...@163.com, Hui Zhang writes: Hello all: do I need a calibration after I used external 10Mhz stand? At the very least you need to run the blue key + W calbration if you change to or from external reference, because that is entirely based on the 20MHz base frequency Comb Generators output. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
