Re: [time-nuts] Z3816A Control and Cleaning
When I worked at H-P, the original H-P, Loveland instrument division the last stage for circuit boards coming off the soldering process was a trip through a regular home dishwasher with tap water and Calgonite. It got ionic contamination off the boards better than anything else we tried. I often run boards from instruments I've gotten on e-bay through the dishwasher if they are really filthy. When my cat peed in my Z3816A and blew up the line operated power supply I bought another power supply and washed the rest of the instrument by hand with detergent and water, 91% IPA, and dried it in the oven at 125F. There were some parts that did not look like they would like the force of the water in the dishwasher. It's worked well for years since then. hld On 1/23/2014 11:42 PM, Larry McDavid wrote: Folks, soap and detergent are not the same thing. Larry On 1/23/2014 11:22 PM, Glenn Little wrote: Tektronix used to clean their oscilloscopes in a soap and water bath in something like a dish washer. This was published in Tek Scope V4 #4 July 1972. I can send the pdf if interested. Glenn WB4UIV ... -- Howard L. Davidson h...@speakeasy.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] Examples of leap-seconds in local timezones
Ah, yes, the time jump. Reminds me of the time jump off of the Empire State building in Men in Black III. Sure seems like the jump should be taken in increments smaller than an integer second. We have the technology. :-) Bill Hawkins -Original Message- From: Magnus Danielson Sent: Thursday, January 23, 2014 9:42 PM I was looking for examples closer to the international date-line. ___ time-nuts mailing 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] Morion MV89A position
This issue has been discussed at length several times. Too much insulation is not necessarily desirable since the oscillator power has to be dissipated and the oven design of the MV89 wasn't meant to be put in a dewar. Better reduce the temperature gradient then fully isolate the OCXO. The upside-down position is not an issue in my opinion. On Fri, Jan 24, 2014 at 5:26 AM, Paul Cianciolo pa...@snet.net wrote: Hello all, I have had a MV89A running now for a couple of years now. It is inside of a Dewar along with bypassing capacitors and the adjustment pot. The end is sealed insulation. For a matter of convenience the oscillator is mounted upside down. I am planning on reconfiguring the box it is in and adding a divider circuit and some other items. So 2 questions 1) Is the fact that the mv89a is inside a Dewar causing any short term or long term adverse effects? 2) Is running the oscillator in the upside down position having any adverse effects? Since I am reconfiguring the box, I plan on mounting the oscillator in the best possible position, and sealing up the Dewar. Any comments please? PaulC W1VLF ___ time-nuts mailing 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] Z3816A Control and Cleaning
Is Calgonite just a brand name for regular dish-washer powder? (Not being a US denizen, the name passes me by). Thx Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Howard Davidson Sent: 24 January 2014 08:12 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816A Control and Cleaning trip through a regular home dishwasher with tap water and Calgonite. ___ time-nuts mailing 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] Help for general GPIB problem
John, thank you for your help. The idea to use IBDEV resulted from the following official NI statement: Snip For current and new GPIB applications, IBDEV should be used. IBFIND will return a board or device descriptor based off the device templates in the GPIB.ini file. Since IBFIND relies on GPIB.ini to return the board or device descriptor, it is difficult to port. For example, with the device templates, the device name can be changed to a custom name. Unless the device templates are ported to the target machine, the call will fail. IBFIND is found in older applications and can be easily updated to using IBDEV instead. IBDEV is far more portable in that it frees the application from the need to rely on specific device names. IBDEV also returns a board or device descriptor but allows you to programmatically specify all the required input parameters in the parameter list of IBDEV (thus avoiding the need to refer to device templates). IBDEV should be used when creating a new GPIB device application. IBFIND should still be used to open a GPIB board communication session, not for communication with instruments. Snip--- But i will of course follow your suggestion to look up Timelab's enumeration function. 73's de Ulrich, DF6JB -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von John Miles Gesendet: Freitag, 24. Januar 2014 08:58 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] Help for general GPIB problem You probably want ibfind() rather than ibdev(). Take a look at gpibport.cpp in the TimeLab source (drivers/shared/gpibport.cpp under the installation folder), in the enumerate_ports() function. -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Thursday, January 23, 2014 3:23 AM To: Time nuts Subject: [time-nuts] Help for general GPIB problem Gentlemen, I am just going to improve my EZGPIB utility so that it can make use of more than one GPIB-interface (supported by GPIB32.Dll, not Prologix). I have been trying to enumerate all detected interfaces by using ibdev(bi,0,0,T300ms,0,1) in a loop where bi starts with 0 and is incremented by 1 until the result of the call gets negative. Much to my surprise this loop detects 4 (!) interfaces GPIB0 to GPIB3 even if absolutely NO interface is connected to the pc. What am I doing wrong. Is 4 the maximum number of interfaces that may be handled by GPIB32.Dll What do I need to do to find the real number of detected interfaces ? Best regards and TIA for your answers Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ time-nuts mailing 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] Help for general GPIB problem
Hmm, yes, it's tough to say what might have motivated that recommendation. I have no idea what a device template is, or what it might mean for ibfind() to be difficult to port. It's worked for many years here, with both genuine and emulated (HP 82350-series) adapters. The one issue I've experienced is the inability of 64-bit Windows apps to detect the emulated NI488.2 devices provided by Agilent I/O Libraries for the 82357 adapters. This is why the 32-bit drivers are still linked with gpib-32.obj rather than the newer ni4882.obj API module. -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Friday, January 24, 2014 1:29 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Help for general GPIB problem John, thank you for your help. The idea to use IBDEV resulted from the following official NI statement: Snip For current and new GPIB applications, IBDEV should be used. IBFIND will return a board or device descriptor based off the device templates in the GPIB.ini file. Since IBFIND relies on GPIB.ini to return the board or device descriptor, it is difficult to port. For example, with the device templates, the device name can be changed to a custom name. Unless the device templates are ported to the target machine, the call will fail. IBFIND is found in older applications and can be easily updated to using IBDEV instead. IBDEV is far more portable in that it frees the application from the need to rely on specific device names. IBDEV also returns a board or device descriptor but allows you to programmatically specify all the required input parameters in the parameter list of IBDEV (thus avoiding the need to refer to device templates). IBDEV should be used when creating a new GPIB device application. IBFIND should still be used to open a GPIB board communication session, not for communication with instruments. Snip--- But i will of course follow your suggestion to look up Timelab's enumeration function. 73's de Ulrich, DF6JB -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von John Miles Gesendet: Freitag, 24. Januar 2014 08:58 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] Help for general GPIB problem You probably want ibfind() rather than ibdev(). Take a look at gpibport.cpp in the TimeLab source (drivers/shared/gpibport.cpp under the installation folder), in the enumerate_ports() function. -- john, KE5FX Miles Design LLC -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts- boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Thursday, January 23, 2014 3:23 AM To: Time nuts Subject: [time-nuts] Help for general GPIB problem Gentlemen, I am just going to improve my EZGPIB utility so that it can make use of more than one GPIB-interface (supported by GPIB32.Dll, not Prologix). I have been trying to enumerate all detected interfaces by using ibdev(bi,0,0,T300ms,0,1) in a loop where bi starts with 0 and is incremented by 1 until the result of the call gets negative. Much to my surprise this loop detects 4 (!) interfaces GPIB0 to GPIB3 even if absolutely NO interface is connected to the pc. What am I doing wrong. Is 4 the maximum number of interfaces that may be handled by GPIB32.Dll What do I need to do to find the real number of detected interfaces ? Best regards and TIA for your answers Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ time-nuts mailing 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] Morion MV89A position
Paul wrote: 1) Is the fact that the mv89a is inside a Dewar causing any short term or long term adverse effects? Dewars are appropriate for OCXOs that are designed to work in Dewars. They do not generally improve the temperature regulation of OCXOs that were not designed to work in Dewars, and can significantly compromise the temperature regulation of some OCXOs. An oven works by heating the crystal (and often other circuitry) with a heating element (this is the pull up), which is balanced by heat loss to the ambient environment (this is the pull down). By putting the MV89 in a Dewar, you have reduced the pull down that balances the heater. This means that the heater must stably deliver much less heat than it was designed to, and the heater control circuitry is operating far from its target design point. It may have enough range to work this way, but it is not operating at the design-center sweet spot that the designers chose. This applies to any OCXO, and any form of insulation you use. What you want to achieve is a pull-down rate (rate of heat loss to ambient) similar to the rate anticipated by the thermal designers, but with some integration to slow down the change in cooling rate that occurs when the ambient temperature changes quickly. This gives the heater control servo more time to adjust, thereby improving regulation as the ambient temperature changes. To accomplish this, you want to add thermal capacitance, NOT thermal resistance. The Dewar adds thermal resistance. My solution is to seal the OCXO up in a fairly heavy cast aluminum box (I put the OCXO on teflon or nylon standoffs so there is no direct metal heat-conducting path from the OCXO to the box). You don't really need to do anything more than this for most OCXOs. If you want, you can mount the cast box in another enclosure (again, on thermally-insulating standoffs) with a thermostatically-controlled fan. When I do this, I bond a thermal sensor to the cast aluminum box and use that to drive the fan, so the cast box remains at a constant temperature regardless of changes in the ambient temperature. 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] Nortel GPSDO osc age alarm
Hi Volker One possibility, as I found with one of these recently, is that your oscillator has aged such that the required EFC voltage for 10MHz output is now outside the range provided by the board. The EFC behaviour can be tracked if Lady Heather is enabled from switch on and the DAC voltage monitored. The EFC voltage should start at 3 volts, in my case reported by LH as 3.02 Volts, and will sit at this level until enough satellites are being tracked for the board to decide it can start the conditioning process, at which point the DAC voltage will ramp upwards over the course of a few seconds until the point is reached where the oscillator frequency crosses 10MHz and the control loop takes over. All standard stuff of course but, as you've discovered, if the oscillator hasn't reached 10MHz by the time the EFC voltage reaches, in my case anyway, approximately 5.6 volts the board's OSC report switches to BAD and Normal OSC age switches to OSC age alarm and LH highlights both in red. The EFC voltage finishes its ramp at 6 Volts, reported as 6.04 Volts, and then just sits there, all exactly as you're seeing. Having removed my faulty oscillator, something that needs to be done VERY carefully to avoid damage to the board, I found that it required an EFC voltage of just under 6.6 Volts for the the output frequency to reach 10MHz. The seller, fluke.l, was very helpful as always and offered to supply a replacement 34310-T oscillator, this one did have it's required EFC voltage in the correct range and resolved the problem. However, whilst waiting for the replacement to arrive I left the original oscillator on test and monitoring it for a while suggested that the only thing wrong with it was the required EFC voltage, so I reconnected it to the board using a wired lash-up on the bench with a simple 2 Volt level shifter inserted into the control loop and did indeed get a locked condition with Lady H reporting the DAC voltage from the board as close to 4.5 volts. This suggests that whilst the board design requires the oscillator EFC Voltage at 10 MHz to be between 3 and 6 Volts an oscillator that falls outside this range shouldn't automaticall be assumed to be faulty in more general terms, although it's obviously getting a bit long in the tooth and that doesn't help much if it happens to be soldered into your circuit board ! Whilst it is possible to remove and replace the original oscillator there is an alternative to physical replacement, one which I've now implemented, and this uses the mounting positions already available beneath the oscillator, not usable though until it's removed, to fit a couple of SMA or SMB connectors. These two connectors couple the 10MHz signal from the oscillator into the board (J9) and the EFC Voltage out to the oscillator (J10). Although there is a regulated supply available from the oscillator, which might be expected to supply the EFC circuitry, in practice this connection does not seem to be required. I have not investigated further as yet to determine whether the board auto senses and uses this supply if it is present, or whether it always just ignores it, but it doesn't seem to be an issue either way and it's interesting to note, at the extremes anyway, that LH does report the DAC voltage to be the same in both instances. The oscillator can be powered from the board or given its own supply, in which case the only required connections between them are the two coax leads. Using this arrangement, and some variation of a positive or negative level shifter if required, it becomes possible to use different oscillators with the Nortel board and it does become an even more interesting toy. One limitation though when using the Nortel boards in this way is that they don't seem to share the versatility of the Thunderbolt when it comes to modifying the oscillator conditioning parameters. It's suggested in the LH documentation that such commands are currently undocumented but that also leaves the possibility that any such change might only be a firmware option. If anyone has further information on this that would be much appreciated. I've been sufficiently impressed with the modified unit that I'm seriously considering modifying another one, even though it doesn't actually need it, although not over enthusiastic about repeating the oscillator removal. However, an added bonus with this configuration is that it's also more forgiving when it comes to any damage caused during removal of the original oscillator, since the pads for the external connectors are separate from the internal oscillator pads. Obviously it needs to be ensured that any necessary continuity is maintained but that could be easier if a board mounted oscillator is no longer required. The later single board unit, the NTBW50AA, has a similar external connector arrangement but in this case
Re: [time-nuts] Examples of leap-seconds in local timezones
I would support a leap minute. It will still be far enough in the future that I will not have to deal with it :) But then we would lose that wonderful subject of conversation and we would lose the practice of doing it somewhat regularly. I can see that the lack of practice could easily make it into a bigger problem. Didier KO4BB Wojciech Owczarek wojci...@owczarek.co.uk wrote: Magnus, I have little experience with radio-based public time dissemination services, but some with GPS/NTP/PTP, so here's some info - hope it's of some value to you. For US and European exchanges, the leap second time happens outside trading hours, so maybe that's why we've heard little (horror) stories. This is definitely not an easy thing to deal with during trading, unless your messaging protocol actually has specific leap second extensions - which I'm not aware of any of the ones I know having. This is how the Linux kernel running UTC does it (assuming it's been told by NTP/PTP/GPS/user and the respective leap second kernel flag was set - and for example, a broken IRIG-B box somewhere hadn't forgotten to tell some of your NTP servers about this and your quorum blocked it): - If we're removing a second, Linux system clock will change from 23:59:58.9 straight to 00:00:00.0 - If we're inserting a second, Linux system clock will run the last second second twice: 23:59:59.9 will change again to 23:59:59.0 (that's the kernel internal / UTC time, time formatting functions will output the :60 value at insertion time). This approach can potentially be problematic for some applications, especially the insertion, which is essentially a step backwards, so some institutions / vendors propose an alternative approach, which is the leap second smear - I think Google was advocating that one: this is where you gradually add/take the extra time throughout the whole leap second day (which would be an approx. 11.6 ppm offset if you started from midnight - so you'd have to model this carefully to bring it back to normal soon after the leap second midnight). Those alternative methods of time insertion may be fine if they're used only internally within an organisation that doesn't provide timestamped data to other organisations, without also providing time services to them - or basically, all is well as long as interconnected parties use the same method of dealing with this. *personal opinion* While the leap second is a somewhat inconvenient phenomenon, while it's still there, it's there and we have to deal with it. I think that most of the problems around it that people talk about are a little bit of FUD resulting purely from the lack of adequate testing. This is based on my experience with computer/network kit - this wasn't meant to be an absolute statement. I'd say let the IERS keep computing it but let's drop it from UTC and let's do a one-off leap hour in some 4,000 years :-) Regards Wojciech ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Sent from my Motorola Droid Razr 4G LTE wireless tracker while I do other things. ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
Whilst on second thoughts it does seem a bit odd that this oscillator has passed 10MHz and still not locking this might be linked to the alarms being generated at around 5.6 volts as per my previous comment, even though the EFC voltage at the extreme does, theoretically at least, seem to be enough to implement the control function. I would still be very inclined with this unit to remove the oscillator and test it on its own. Regards Nigel GM8PZR In a message dated 23/01/2014 23:59:34 GMT Standard Time, ail...@t-online.de writes: Hi! I bought a Trimble/Nortel GPSDO http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m 1497.l2648 and Lady Heather's now tells me that everything is alright - except - DAC 6.04V - OSC BAD - osc age alarm The rectangle 10MHz output signal (J5) shows a signal at about 9.8MHz (a deviation of about 200kHz), wobbling 4Hz up and down. Oddly enough, the direct oscillator output (J4) shows a sine wave at a stable 10.004MHz (a deviation of 0.4Hz). It seems to me it's not the oscillator that is bad but the servo loop - what can I do? Thank you Volker ___ time-nuts mailing 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] Z3815A date problem fixed?
Hi all, There was some consternation here 5 months ago when Z3815A GPSDOs began reporting a date 1024 weeks in the past. This was due to a storage overflow condition in the Furuno GPS receiver in the Z3915A. The designers probably never anticipated that they would still be in use 20 years later Oscillator discipline was unaffected as the 1 pps was still good. Obsessional types like me looked for a solution. There didn't seem to be any knowledge out there about reprogramming the receivers so it had to be a transplant. Furuno GT-8031 timing receivers are available on ebay and not prohibitively expensive. They are about half the size of a matchbox and work at 3.3V TTL levels. The interface connector is a 2mm pitch 2X5 pin header and the antenna connection is a pigtail with a Hirose u.fl connector. The interface is 9600,n,8,1. I picked one up a few months ago and it took a while to get the appropriate connectors etc but I eventually found enough time to make a little interface PCB compete with a Li button cell backup battery. I lashed it up tonight into the Z3815A and it works!!! The GPS locks the oscillator and the Z3815A reports the correct time date. As I write this it's been going for an hour or so and the survey is not complete, the Z3815A still reporting reduced accuracy. It is showing an antenna alarm for some reason so the yellow operation alarm LED is lit. That may be because I'm powering the receiver externally at the moment and there would be no current being drawn from the Z3815A 5 volt supply. I'll work on that in the morning. The interface board draws a total of about 100 mA including the antenna current and I'm hoping that won't be high enough to give an antenna alarm in the other direction. If so I'll have to change the 3.3 volt supply from being zener stabilized to being series voltage dropped. More news as it breaks!! Morris ___ time-nuts mailing 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] Morion MV89A position
Le 24 janv. 2014 à 05:26, Paul Cianciolo a écrit : Hello all, I have had a MV89A running now for a couple of years now. It is inside of a Dewar along with bypassing capacitors and the adjustment pot. The end is sealed insulation. For a matter of convenience the oscillator is mounted upside down. I am planning on reconfiguring the box it is in and adding a divider circuit and some other items. So 2 questions 1) Is the fact that the mv89a is inside a Dewar causing any short term or long term adverse effects? 2) Is running the oscillator in the upside down position having any adverse effects? Since I am reconfiguring the box, I plan on mounting the oscillator in the best possible position, and sealing up the Dewar. I very much doubt that the absolute position has any effect. Otherwise I would expect to see This Side Up and an arrow marked North on the casing. There are none on my samples. Any acceleration will cause phase shift but you say that you will be adding circuitry, so I guess it will be powered off for and so you will not see that. You are more like likely to see some effect from the power cycle than anything else. If you have a measuring instrument available it would be nice to take some data before and after the operation and report back what you see. Regards Any comments please? PaulC W1VLF ___ time-nuts mailing 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] Z3816A Control and Cleaning
All, I got up this AM to a nice collection of responses and information. Thanks to all. Glenn, thanks for the Tek Scope article. Hal, I think that is the command I remember. I was searching under Z3816A, not Z3801A. I'll give it a try. Perhaps I was not clear about 'soap'. What I was planning was dish detergent. I can choose either regular dish detergent or dish washer detergent. Any preference? These are not the same. Any guess as to how I know this? I'll report back after further effort. Now, off to work. Thanks again. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Glenn Little Sent: Friday, January 24, 2014 1:00 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816A Control and Cleaning Tektronix used to clean their oscilloscopes in a soap and water bath in something like a dish washer. This was published in Tek Scope V4 #4 July 1972. Glenn WB4UIV At 10:13 PM 1/23/2014, you wrote: Joe Been a while. Sounds like a reasonable approach with the soap and water. The key is not to force water into the inductors. I take soapy water and a tooth brush it works wonders. Then dry in an oven at about 100 degrees just to drive off the moisture. Very gentle. I guess the other point is to get a better feel for the gunk. Does soap and water do it. The fact that IPA didn't is interesting. It may be oil based. Good luck Paul WB8TSL/1 On Thu, Jan 23, 2014 at 9:41 PM, J. L. Trantham jlt...@att.net wrote: I recently acquired a Z3816A as a 'spare' and it does not work reliably. The ALARM LED sometimes comes on and sometimes doesn't. Sometimes it tracks and locks appropriately and other times it goes into HOLDOVER. The main PCB is very dirty and has the appearance that it has been in a humid and dusty environment. I am suspicious that there are some 'leakage' issues related to this dirt and would like to wash the board. What would the group recommend for cleaning the board? I sprayed it with 91% IPA and used a paint brush to try to clean the board. Some improvement but still dirty. I was thinking of warm soapy water with a paint brush followed by warm water followed by 91% IPA followed by a hairdryer then an hour or two in an oven at about 100 to 150 degrees F. Thoughts? I'm a bit concerned about the inductors and the possibility of water leading to problems with them. Also, I seem to recall a command that can be sent by SatStat to change from GPS time to UTC time but I can't find it in my files. Is there such a command or am I hallucinating? Thanks in advance. Joe ___ time-nuts mailing 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] PICPET- was Affordable (cheap) COTS (etc)
The SX was/is a great chip. (I still use them on a near daily basis) Troubled history, though. This is part of why Parallax developed the Propeller. The premise behind the propeller, is that it is based on the Virtual Peripherals of the SX. You simulate peripherals by having interrupt code running many 'threads'. With modern processors shrinking fast, why not just give these 'threads' of interrupt code their own processor? On top of that these cores are 32bit cores. As for life of the Propeller, fear not. It will be around for a long, long time! What killed the SX chip was the manufacturer/IP holder of the design, which parallax was not. Parallax owns the IP and production of the Propeller. Pics are great, except that I have a hard time figuring out which one to use. Option overload big time! Dan On 1/23/2014 7:09 PM, time-nuts-requ...@febo.com wrote: Good thread. Yes I am very aware of the parallax propeller. As you both say kind of a crazy chip. I have used another product the SXB micros. They run Basic at 80 Mhz and are so cheap that If I have more than a few chips I just switch over. Unfortunately they are obsolete in the dip form. When I looked at the propeller my take away was that it was such an odd chip I actually did not want to deal with it figuring its life was just a few years. Its advantage was the ability to have so many things running in parallel. The great thing about the PICs are there are such a wide diversity of them at really cheap prices. Tom thanks for the insight on the synchronous clock. Did not realize that. Regards Paul WB8TSL ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
...thanks, Bob, it seems to be the oscillator, that is at it's limit, it cannot tune to 10 MHz at full EFC voltage, see new thread (started by Mark). Volker Am 24.01.2014 01:09, schrieb Bob Camp: Hi That’s a cell phone base station board. It’s got a bunch of outputs, some of which are related to the cell network it was built for rather than 10MHz. I’d bet your 9.8 MHz output is one of those. They are DDS based so there likely is some range of possible outputs. The age alarm is not unusual on a newly powered up board. It’s moving faster than it should. It may settle down. The DAC at limit is not a real good sign …. Bob On Jan 23, 2014, at 6:43 PM, Volker Esper ail...@t-online.de wrote: Hi! I bought a Trimble/Nortel GPSDO http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2648 and Lady Heather's now tells me that everything is alright - except - DAC 6.04V - OSC BAD - osc age alarm The rectangle 10MHz output signal (J5) shows a signal at about 9.8MHz (a deviation of about 200kHz), wobbling 4Hz up and down. Oddly enough, the direct oscillator output (J4) shows a sine wave at a stable 10.004MHz (a deviation of 0.4Hz). It seems to me it's not the oscillator that is bad but the servo loop - what can I do? Thank you Volker ___ time-nuts mailing 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] Z3816A Control and Cleaning
On 1/23/2014 11:30 PM, Hal Murray wrote: Also, I seem to recall a command that can be sent by SatStat to change from GPS time to UTC time but I can't find it in my files. Is there such a command or am I hallucinating? My notes for the Z3801A say: :diag:gps:utc 1 http://www.realhamradio.com/GPS_User_Notes.htm (undocumented) My Z3801 notes which came from Bill Jones K8CU show the same however in upper case. I added a note that it did not work until local time zone was set to 0hrs 0min. Don H ___ time-nuts mailing 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] Z3816A Control and Cleaning
Tek article is quite good. Time to find a power washer for my tek 2465Bs. Maybe that will fix the memories. Not. Regards Paul WB8TSL On Fri, Jan 24, 2014 at 10:57 AM, Donald Henderickx wa9...@sandprairie.netwrote: On 1/23/2014 11:30 PM, Hal Murray wrote: Also, I seem to recall a command that can be sent by SatStat to change from GPS time to UTC time but I can't find it in my files. Is there such a command or am I hallucinating? My notes for the Z3801A say: :diag:gps:utc 1 http://www.realhamradio.com/GPS_User_Notes.htm (undocumented) My Z3801 notes which came from Bill Jones K8CU show the same however in upper case. I added a note that it did not work until local time zone was set to 0hrs 0min. Don H ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
Thanks so much, Nigel, for this very interesting mail. Yes, the voltages are exactly as my ones. And yes, I've removed the oscillator, already. I then removed the thermal isolation from the osc, as well as the label, in slight hope for a hidden tuning screw. Of course, there isn't any. I, too, had this idea to level shift the EFC voltage. So I took seat at my computer to find out, which maximum EFC voltage would be ok. And saw your mail. Do you have any further information about the osc? The number on the sign (Trimble *0110-2450-T* *34310-T*) isn't really informative. By the way: When removing the big Trimble label I found a smaller one beneath, reading DOC2127 0101/1940; I think it's a Tekelc osc? Is there a pull-up resistor behind the EFC input pin so that I could use two diodes for level shifting? Or how did you? This part is more thrilling than I expected... Regards Volker Am 24.01.2014 12:08, schrieb gandal...@aol.com: Hi Volker One possibility, as I found with one of these recently, is that your oscillator has aged such that the required EFC voltage for 10MHz output is now outside the range provided by the board. The EFC behaviour can be tracked if Lady Heather is enabled from switch on and the DAC voltage monitored. The EFC voltage should start at 3 volts, in my case reported by LH as 3.02 Volts, and will sit at this level until enough satellites are being tracked for the board to decide it can start the conditioning process, at which point the DAC voltage will ramp upwards over the course of a few seconds until the point is reached where the oscillator frequency crosses 10MHz and the control loop takes over. All standard stuff of course but, as you've discovered, if the oscillator hasn't reached 10MHz by the time the EFC voltage reaches, in my case anyway, approximately 5.6 volts the board's OSC report switches to BAD and Normal OSC age switches to OSC age alarm and LH highlights both in red. The EFC voltage finishes its ramp at 6 Volts, reported as 6.04 Volts, and then just sits there, all exactly as you're seeing. Having removed my faulty oscillator, something that needs to be done VERY carefully to avoid damage to the board, I found that it required an EFC voltage of just under 6.6 Volts for the the output frequency to reach 10MHz. The seller, fluke.l, was very helpful as always and offered to supply a replacement 34310-T oscillator, this one did have it's required EFC voltage in the correct range and resolved the problem. However, whilst waiting for the replacement to arrive I left the original oscillator on test and monitoring it for a while suggested that the only thing wrong with it was the required EFC voltage, so I reconnected it to the board using a wired lash-up on the bench with a simple 2 Volt level shifter inserted into the control loop and did indeed get a locked condition with Lady H reporting the DAC voltage from the board as close to 4.5 volts. This suggests that whilst the board design requires the oscillator EFC Voltage at 10 MHz to be between 3 and 6 Volts an oscillator that falls outside this range shouldn't automaticall be assumed to be faulty in more general terms, although it's obviously getting a bit long in the tooth and that doesn't help much if it happens to be soldered into your circuit board ! Whilst it is possible to remove and replace the original oscillator there is an alternative to physical replacement, one which I've now implemented, and this uses the mounting positions already available beneath the oscillator, not usable though until it's removed, to fit a couple of SMA or SMB connectors. These two connectors couple the 10MHz signal from the oscillator into the board (J9) and the EFC Voltage out to the oscillator (J10). Although there is a regulated supply available from the oscillator, which might be expected to supply the EFC circuitry, in practice this connection does not seem to be required. I have not investigated further as yet to determine whether the board auto senses and uses this supply if it is present, or whether it always just ignores it, but it doesn't seem to be an issue either way and it's interesting to note, at the extremes anyway, that LH does report the DAC voltage to be the same in both instances. The oscillator can be powered from the board or given its own supply, in which case the only required connections between them are the two coax leads. Using this arrangement, and some variation of a positive or negative level shifter if required, it becomes possible to use different oscillators with the Nortel board and it does become an even more interesting toy. One limitation though when using the Nortel boards in this way is that they don't seem to share the versatility of the Thunderbolt when it comes to modifying the oscillator
Re: [time-nuts] Z3816A Control and Cleaning
Larry, Thanks for the info. What is 'RO'? I am not familiar with that abbreviation. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Thursday, January 23, 2014 10:34 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816A Control and Cleaning I recommend against using tap water on any electronics. Use RO or distilled water; that won't leave behind minerals when it evaporates. Most IPA is only 70%; the balance is water. For flux removal, use 99% or anhydrous IPA, available at most industrial hardware stores. And, I surely would not use soap of any kind. You can use a detergent but only a tiny amount is needed to reduce the surface tension. If you don't get it all off by flushing, residue after evaporation of any surfactant is not good... Larry On 1/23/2014 7:13 PM, paul swed wrote: Joe Been a while. Sounds like a reasonable approach with the soap and water. The key is not to force water into the inductors. I take soapy water and a tooth brush it works wonders. Then dry in an oven at about 100 degrees just to drive off the moisture. Very gentle. I guess the other point is to get a better feel for the gunk. Does soap and water do it. The fact that IPA didn't is interesting. It may be oil based. Good luck Paul WB8TSL/1 On Thu, Jan 23, 2014 at 9:41 PM, J. L. Trantham jlt...@att.net wrote: I recently acquired a Z3816A as a 'spare' and it does not work reliably. The ALARM LED sometimes comes on and sometimes doesn't. Sometimes it tracks and locks appropriately and other times it goes into HOLDOVER. The main PCB is very dirty and has the appearance that it has been in a humid and dusty environment. I am suspicious that there are some 'leakage' issues related to this dirt and would like to wash the board. What would the group recommend for cleaning the board? I sprayed it with 91% IPA and used a paint brush to try to clean the board. Some improvement but still dirty. I was thinking of warm soapy water with a paint brush followed by warm water followed by 91% IPA followed by a hairdryer then an hour or two in an oven at about 100 to 150 degrees F. Thoughts? I'm a bit concerned about the inductors and the possibility of water leading to problems with them. Also, I seem to recall a command that can be sent by SatStat to change from GPS time to UTC time but I can't find it in my files. Is there such a command or am I hallucinating? Thanks in advance. Joe ___ time-nuts mailing 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. -- 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] Z3816A Control and Cleaning
Oops! RO is Reverse Osmosis. I incorrectly assumed that was widely known. I've had an RO system under my kitchen sink for 30 years. Even CostCo sells RO systems you can install yourself. There is a separate spigot faucet on the sink for this mineral-free water. RO systems first pass city water through a fine particle filter, then allow only pure water to pass through an osmotic membrane into a low-pressure storage tank. Before delivery out the separate spigot, that RO water is passed through an activated carbon filter. All this hardware resides on a smallish vertical platform under your kitchen sink. Here in Anaheim, California, where all water is imported directly or indirectly, the mineral content is relatively high. I maintain my RO system carefully and monitor how it performs by measuring the water conductivity, which is commonly referred to in water reports as Dissolved Solids in ppm (parts per million). My city tap water measures between 600 and 800 ppm dissolved solids (and, sometimes higher); my RO system delivers water at 8-12 ppm. True distilled water will measure 0-2 ppm dissolved solids so RO is almost as good, good enough to not make a difference for our purposes, except perhaps in the highest imaginable high-impedance or high-voltage circuits. So, what is it that causes the high dissolved solids content of tap water? It is *salt* in one form or another, generally magnesium and calcium salts, and can include common sodium chloride (table salt). Salt is electrically conductive so measuring water conductivity is a common way to evaluate mineral content. Many years ago a company named Myron-L established and made popular an assumed mixture of salts found in tap water and calibrated water conductivity in dissolved solids. This assumed mixture and reporting in dissolved solids remains popular today. You likely get a water purity report from your local water supplier; look in there and you will find dissolved solids reported in ppm. You may also find specific minerals reported but that is not done by conductivity. Sometimes you see conductivity reported as conductivity (reciprocal of resistance), with no attempt to convert to a dissolved solids percentage. Think of taking a 5 gallon jug of distilled water and adding a teaspoon of table salt. Would you want to drench your electronics with that water? You'll never get all the water blown out or drained out; what water remains will evaporate. What remains after evaporation is the minerals or salt. Not good to have salt on your circuit boards! It is difficult to harm any electronics by drenching them with distilled or RO water. What does not immediately drain out simply evaporates over time but leaves behind no mineral salt and causes no problem. Drop your cell phone into a lake? Immediately soak it in distilled water to dilute the salt in the lake water. Spill coffee on your keyboard? Drench it with distilled water and let it dry. Let anything you get wet, dry thoroughly before re-applying power! Use slightly elevated temperature to accelerate evaporation. Ever wonder what causes water spots on glassware you don't dry with a towel? Those spots are simply mineral salts left when the city tap water evaporates. I often hand wash a few dishes in my kitchen, but then I rinse them with RO water from the convenient sink-top spigot and let them drain dry. Guess what? No water spots because there are no significant minerals in the RO water. Some homes have soft or deionized water provided by a de-mineralizer that uses salt. The result varies widely and this so-called soft water is not mineral-free. Some will use this water for electronic cleaning; I will not and instead use my RO water, which I monitor and know how mineral-free it really is. Want to check your own tap water for dissolved solids? Easy and cheap today. Search eBay for Dissolved Solids Meter and you will find many hand-held, battery powered LCD meters offered for about $10-$12. RO water is convenient and has other uses around the home. We recently suffered a period of very low relative humidity (5%) and I started using an ultrasonic nebulizer humidifier in my bedroom. I fill it with RO water from my kitchen sink and as a result have no mineral powder falling out of the humidified fog. Do any metal finishing at home? I always use only RO water to avoid unexpected results from tap water. Do you enjoy hot tea? Tanic acid in tea is a mineral indicator and tea made with hard water will be very dark in color. Use RO water and the tea will be amber and taste better. Same with coffee... My RO system gets a lot use! Larry On 1/24/2014 9:12 AM, J. L. Trantham wrote: Larry, Thanks for the info. What is 'RO'? I am not familiar with that abbreviation. Joe ... -- Best wishes, Larry McDavid W6FUB Anaheim, California (SE of Los Angeles, near Disneyland) ___ time-nuts mailing
Re: [time-nuts] PICPET- was Affordable (cheap) COTS (etc)
On Thu, Jan 23, 2014 at 2:00 PM, Tom Van Baak t...@leapsecond.com wrote: Has anyone else looked at the Parallax Propeller processor for timing functions? Hi Brian, Oh yes. Really nice chip. But for precise timing applications I had huge problems with phase and temperature stability of its internal PLL. I tried half a dozen different boards purchased over several years. Tech support was not interested in someone who worried about nanoseconds. Well, my disciplining code is going to run as an FLL rather than a PLL to generate the correction for the OCXO or the Rb reference. I didn't think that noise on the PLL multiplier to take the clock from 10MHz (using the OCXO or Rb as the processor clock) to 80MHz would hurt when I am accumulating clock cycles over many 10's of seconds. OTOH, one can clock the processor directly from the reference without the processor clock PLL and run the CPU at 10MHz. The Propeller is static CMOS and will run at any clock speed down to DC. They spec the clock input up to 8MHz but say that it will clock just fine at 10MHz. The PLL will operate at powers of 2 up to 2^4 (16). Most people use a 5MHz crystal and the x16 PLL to clock the processors at 80MHz. I have been told that the Propeller will run at 100MHz just fine. The architecture is really interesting, but it is such an odd chip, with almost zero market visibility these days, that I set aside the goal of using it as the basis of a general purpose 8-channel 6 ns precision counter. You can find various timer and counter examples at obex.parallax.com. If you make progress on the project, please let me know, ok? Wilco. There are some nice things out there using the propeller. By contrast, the PIC chips I use are fully synchronous so when you use 10 MHz atomic references the clock/output jitter and phase stability is almost below what I can measure here. Same with the Propeller. You can clock it directly from the 10MHz reference without using the PLL and then all 8 cores are running synchronously. (They do anyway but usually they are running at 80MHz. I need to try to see just how fast I can run the main clock input.) I just thought that, while the PLL would have a bit more jitter, having the extra 3 bits of resolution would be useful in accumulating the error. Maybe under 2 ps. So that's why I use PIC's as the basis of all my picDIV and picPET projects. But I'm open to using something different in the future. It does seem to be a very interesting processor and seems to me ideal for performing timing functions. One can easily use it to generate pulses at integer divisors of the system clock. At that point one would definitely not want the jitter from the PLL. -- Brian Lloyd, WB6RQN/J79BPL 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] Nortel GPSDO osc age alarm
In a message dated 24/01/2014 17:06:43 GMT Standard Time, ail...@t-online.de writes: Thanks so much, Nigel, for this very interesting mail. Yes, the voltages are exactly as my ones. And yes, I've removed the oscillator, already. I then removed the thermal isolation from the osc, as well as the label, in slight hope for a hidden tuning screw. Of course, there isn't any. Nope, what you see is what you get, planned obsolescence wins again:-) I did find the thermal insulation to be quite useful in reducing the effects of drafts, as carefully observed by blowing on it:-), so well worth keeping in place once all is up and running again. I, too, had this idea to level shift the EFC voltage. So I took seat at my computer to find out, which maximum EFC voltage would be ok. And saw your mail. Do you have any further information about the osc? The number on the sign (Trimble *0110-2450-T* *34310-T*) isn't really informative. By the way: When removing the big Trimble label I found a smaller one beneath, reading DOC2127 0101/1940; I think it's a Tekelc osc? This is a comment from page 26 of the Nortel GPSTM General Spec available from Didier's site.. --- XXX will identify which OCXO was used in the particular device. XXX is to be either T, Oak, or T2. The T identifies the Tekelec Doc-1903 device and the Oak indicates the OFC-4895 device from Oak Frequency Control Group. A T2 will indicate the Tekelec Doc-2127 device. -which is interesting as it suggests your oscillator to be a T2 even though it's marked T. I'll have to take a closer look at mine:-) Is there a pull-up resistor behind the EFC input pin so that I could use two diodes for level shifting? Or how did you? I've got no information on the internal circuitry so I just assumed it would be a reasonably high impedance and used a single IC as a non-inverting unity gain summing amp powered from the onboard 12V supply for the oscillator to add, in my case, approximately 2V to the DAC output from the circuit board. I used a TL071, but only because that's what I had to hand, with 12K between the output and neg input and another 12k from the neg input to ground, then two 12k input resistors feeding into the pos input, one of which was connected to the EFC output from the board and the other biased very approximately to 2 Volts using a 4k7 and a 1K resistor as a divder across the 12V supply. Again no particular significance to the 12K, I just had some within easy reach. The output from the op amp was then used to feed the EFC voltage to the oscillator, and that was it. I hope that makes sense:-) In this instance I didn't make any attempt to further stabilise the supply to the op amp or the 2V reference but it was only intended to prove the point and I figured the control loop could take care of any small variations, and it actually worked quite well. Since then I've added the SMB connectors to the board and I'm running the replacement oscillator via a couple of pigtails and no offset for that one. Next step, assuming I ever get round to it:-), will be a proper enclosure with connections for an external oscillator, and perhaps even internal switching via a latching coax relay to allow internal or external options but will wait and see on that. Given the control limitations I mentioned earlier though I'm now considering perhaps leaving the other Nortel board as is and instead putting the effort into implementing a similar arrangement for a Thunderbolt, which of course has already been done by John Miles as referenced here http://www.ke5fx.com/tbolt.htm So, although I didn't feel over happy about having a faulty oscillator to start with, I'm actually very pleased with the way it turned out:-) Regards Nigel GM8PZR This part is more thrilling than I expected... Regards Volker Am 24.01.2014 12:08, schrieb gandal...@aol.com: Hi Volker One possibility, as I found with one of these recently, is that your oscillator has aged such that the required EFC voltage for 10MHz output is now outside the range provided by the board. The EFC behaviour can be tracked if Lady Heather is enabled from switch on and the DAC voltage monitored. The EFC voltage should start at 3 volts, in my case reported by LH as 3.02 Volts, and will sit at this level until enough satellites are being tracked for the board to decide it can start the conditioning process, at which point the DAC voltage will ramp upwards over the course of a few seconds until the point is reached where the oscillator frequency crosses 10MHz and the control loop takes over. All standard stuff of course but, as you've discovered, if the oscillator hasn't reached 10MHz by the time the EFC voltage reaches, in my case anyway, approximately 5.6 volts the board's OSC report switches to
Re: [time-nuts] Nortel GPSDO osc age alarm
Volker, I have also a Trimble Nortel NTG550AA and fortunately it works very well from the beginning. I have a downloaded manual and some other info that I can send you if interested. And one word of caution: if you observe the cable that goes from the main board to the small interface board, you will see that one of the connectors is reversed so be careful if you make a custom one for your cabinet, do it in the same fashion. Using a normal cable produces bizarre results that can actually drive you nuts, don't ask how I know. The coax connector, J5 is a 9.8304 MHz output, an odd frequency used by the cell tower equipment, J4 carries 1/2 PPS (even seconds), the next one (J1) is the for the antenna and J4 is the 10 MHz output. You already know that but I want to note that the 9.8304 frequency has mislead some users to think that it was the 10 MHz output, not your case. The seller (Bob Mokia , fluke.l) is well known to the Time Nuts, he has a technical background and normally known quite well what he sells and is very positive about solving the problems that may arise, his only problem is that his English is worse than mine . I think that he regularly monitors this list. I have observed a strange thing on this offering, at the end of the page he says: power on it ... after 30 minutes/it will locked/10mhz come on the SMB connector 1pps on the back d sub connector I never heard of a 1PPS signal on these units, only 1/2 PPS on the J4 coax and I had asked on this list if anybody had found how to extract 1 PPS from the unit. I have to put a scope on the DSR pin because it is the only connected to the main board other than TxD and RxD. Could you verify this on your unit when you change the OCXO and get it running? Best regards, Ignacio EB4APL On 24/01/2014 16:23, Volker Esper wrote: ...thanks, Bob, it seems to be the oscillator, that is at it's limit, it cannot tune to 10 MHz at full EFC voltage, see new thread (started by Mark). Volker Am 24.01.2014 01:09, schrieb Bob Camp: Hi That’s a cell phone base station board. It’s got a bunch of outputs, some of which are related to the cell network it was built for rather than 10MHz. I’d bet your 9.8 MHz output is one of those. They are DDS based so there likely is some range of possible outputs. The age alarm is not unusual on a newly powered up board. It’s moving faster than it should. It may settle down. The DAC at limit is not a real good sign …. Bob On Jan 23, 2014, at 6:43 PM, Volker Esper ail...@t-online.de wrote: Hi! I bought a Trimble/Nortel GPSDO http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2648 and Lady Heather's now tells me that everything is alright - except - DAC 6.04V - OSC BAD - osc age alarm The rectangle 10MHz output signal (J5) shows a signal at about 9.8MHz (a deviation of about 200kHz), wobbling 4Hz up and down. Oddly enough, the direct oscillator output (J4) shows a sine wave at a stable 10.004MHz (a deviation of 0.4Hz). It seems to me it's not the oscillator that is bad but the servo loop - what can I do? Thank you Volker ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
9.8304 MHz divided by 300 is 32,768 Hz. Feed that to an electronic clock and you will have an atomic clock of sorts. Regards Thomas Miller, Director of Wireless Services Skyline Network Engineering, LLC 443-250-6381 From: time-nuts-boun...@febo.com time-nuts-boun...@febo.com on behalf of EB4APL eb4...@cembreros.jazztel.es Sent: Friday, January 24, 2014 2:27 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Nortel GPSDO osc age alarm Volker, I have also a Trimble Nortel NTG550AA and fortunately it works very well from the beginning. I have a downloaded manual and some other info that I can send you if interested. And one word of caution: if you observe the cable that goes from the main board to the small interface board, you will see that one of the connectors is reversed so be careful if you make a custom one for your cabinet, do it in the same fashion. Using a normal cable produces bizarre results that can actually drive you nuts, don't ask how I know. The coax connector, J5 is a 9.8304 MHz output, an odd frequency used by the cell tower equipment, J4 carries 1/2 PPS (even seconds), the next one (J1) is the for the antenna and J4 is the 10 MHz output. You already know that but I want to note that the 9.8304 frequency has mislead some users to think that it was the 10 MHz output, not your case. The seller (Bob Mokia , fluke.l) is well known to the Time Nuts, he has a technical background and normally known quite well what he sells and is very positive about solving the problems that may arise, his only problem is that his English is worse than mine . I think that he regularly monitors this list. I have observed a strange thing on this offering, at the end of the page he says: power on it ... after 30 minutes/it will locked/10mhz come on the SMB connector 1pps on the back d sub connector I never heard of a 1PPS signal on these units, only 1/2 PPS on the J4 coax and I had asked on this list if anybody had found how to extract 1 PPS from the unit. I have to put a scope on the DSR pin because it is the only connected to the main board other than TxD and RxD. Could you verify this on your unit when you change the OCXO and get it running? Best regards, Ignacio EB4APL On 24/01/2014 16:23, Volker Esper wrote: ...thanks, Bob, it seems to be the oscillator, that is at it's limit, it cannot tune to 10 MHz at full EFC voltage, see new thread (started by Mark). Volker Am 24.01.2014 01:09, schrieb Bob Camp: Hi That’s a cell phone base station board. It’s got a bunch of outputs, some of which are related to the cell network it was built for rather than 10MHz. I’d bet your 9.8 MHz output is one of those. They are DDS based so there likely is some range of possible outputs. The age alarm is not unusual on a newly powered up board. It’s moving faster than it should. It may settle down. The DAC at limit is not a real good sign …. Bob On Jan 23, 2014, at 6:43 PM, Volker Esper ail...@t-online.de wrote: Hi! I bought a Trimble/Nortel GPSDO http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2648 and Lady Heather's now tells me that everything is alright - except - DAC 6.04V - OSC BAD - osc age alarm The rectangle 10MHz output signal (J5) shows a signal at about 9.8MHz (a deviation of about 200kHz), wobbling 4Hz up and down. Oddly enough, the direct oscillator output (J4) shows a sine wave at a stable 10.004MHz (a deviation of 0.4Hz). It seems to me it's not the oscillator that is bad but the servo loop - what can I do? Thank you Volker ___ time-nuts mailing 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. CONFIDENTIALITY NOTICE: The information contained in this electronic message is confidential information intended for the use of the individual or entity named above. If the reader of this message is not the intended recipient, or an employee or agent responsible for delivering this electronic message to the intended recipient, you are hereby notified that any dissemination or copying of this communication is strictly prohibited. If this message
Re: [time-nuts] Nortel GPSDO osc age alarm
Ignacio, thanks for your message. Answeres within the text: And one word of caution: if you observe the cable that goes from the main board to the small interface board, you will see that one of the connectors is reversed so be careful if you make a custom one for your cabinet, do it in the same fashion. Yes, I've seen that by chance, when disconnecting the board to reassemble the oscillator. Using a normal cable produces bizarre results that can actually drive you nuts, don't ask how I know. It's a wonder you didn't kill the beast... ...the 9.8304 frequency has mislead some users to think that it was the 10 MHz output, not your case. Me, too, at the beginning The seller (Bob Mokia , fluke.l) is well known to the Time Nuts Yeah, of course, I know. The thing is, usually people are cautious naming sellers. Time Nuts' point of view isn't quite that narrow. Ok, yes, I admit, it's Bob ;-) 1pps on the back d sub connector I read that, too, but like you I only found the even PPS. I have to put a scope on the DSR pin because it is the only connected to the main board other than TxD and RxD. Could you verify this on your unit when you change the OCXO and get it running? That's no problem, the GPS stuff works well on my item. I'll post a message. Regards Volker ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
Nice! I didn't know that. But what a number, 300... Why such a digital-hostile factor? Why not 256 or 512? Volker Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net: 9.8304 MHz divided by 300 is 32,768 Hz. Feed that to an electronic clock and you will have an atomic clock of sorts. Regards Thomas Miller, Director of Wireless Services Skyline Network Engineering, LLC 443-250-6381 From: time-nuts-boun...@febo.com time-nuts-boun...@febo.com on behalf of EB4APL eb4...@cembreros.jazztel.es Sent: Friday, January 24, 2014 2:27 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Nortel GPSDO osc age alarm Volker, I have also a Trimble Nortel NTG550AA and fortunately it works very well from the beginning. I have a downloaded manual and some other info that I can send you if interested. And one word of caution: if you observe the cable that goes from the main board to the small interface board, you will see that one of the connectors is reversed so be careful if you make a custom one for your cabinet, do it in the same fashion. Using a normal cable produces bizarre results that can actually drive you nuts, don't ask how I know. The coax connector, J5 is a 9.8304 MHz output, an odd frequency used by the cell tower equipment, J4 carries 1/2 PPS (even seconds), the next one (J1) is the for the antenna and J4 is the 10 MHz output. You already know that but I want to note that the 9.8304 frequency has mislead some users to think that it was the 10 MHz output, not your case. The seller (Bob Mokia , fluke.l) is well known to the Time Nuts, he has a technical background and normally known quite well what he sells and is very positive about solving the problems that may arise, his only problem is that his English is worse than mine . I think that he regularly monitors this list. I have observed a strange thing on this offering, at the end of the page he says: power on it ... after 30 minutes/it will locked/10mhz come on the SMB connector 1pps on the back d sub connector I never heard of a 1PPS signal on these units, only 1/2 PPS on the J4 coax and I had asked on this list if anybody had found how to extract 1 PPS from the unit. I have to put a scope on the DSR pin because it is the only connected to the main board other than TxD and RxD. Could you verify this on your unit when you change the OCXO and get it running? Best regards, Ignacio EB4APL On 24/01/2014 16:23, Volker Esper wrote: ...thanks, Bob, it seems to be the oscillator, that is at it's limit, it cannot tune to 10 MHz at full EFC voltage, see new thread (started by Mark). Volker Am 24.01.2014 01:09, schrieb Bob Camp: Hi That’s a cell phone base station board. It’s got a bunch of outputs, some of which are related to the cell network it was built for rather than 10MHz. I’d bet your 9.8 MHz output is one of those. They are DDS based so there likely is some range of possible outputs. The age alarm is not unusual on a newly powered up board. It’s moving faster than it should. It may settle down. The DAC at limit is not a real good sign …. Bob On Jan 23, 2014, at 6:43 PM, Volker Esper ail...@t-online.de wrote: Hi! I bought a Trimble/Nortel GPSDO http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2648 and Lady Heather's now tells me that everything is alright - except - DAC 6.04V - OSC BAD - osc age alarm The rectangle 10MHz output signal (J5) shows a signal at about 9.8MHz (a deviation of about 200kHz), wobbling 4Hz up and down. Oddly enough, the direct oscillator output (J4) shows a sine wave at a stable 10.004MHz (a deviation of 0.4Hz). It seems to me it's not the oscillator that is bad but the servo loop - what can I do? Thank you Volker ___ time-nuts mailing 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. CONFIDENTIALITY NOTICE: The information contained in this electronic message is confidential information intended for the use of the individual or entity named above. If the reader of this message is not the intended recipient, or an
Re: [time-nuts] Nortel GPSDO osc age alarm
On 1/24/14 11:57 AM, Volker Esper wrote: Nice! I didn't know that. But what a number, 300... Why such a digital-hostile factor? Why not 256 or 512? Volker Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net: 9.8304 MHz divided by 300 is 32,768 Hz. Feed that to an electronic clock and you will have an atomic clock of sorts. Regards 9.8304 is 300 baud * 32768. So you can generate all the conventional digital data rates (1200,2400,.., 38.4k with powers of two). Typically, a UART wants to see a clock that is 16x or 8x bit time, so you need something a bit higher. ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
Oukaay - I should've known... Thanks, Jim! Am 24.01.2014 21:12, schrieb Jim Lux: On 1/24/14 11:57 AM, Volker Esper wrote: Nice! I didn't know that. But what a number, 300... Why such a digital-hostile factor? Why not 256 or 512? Volker Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net: 9.8304 MHz divided by 300 is 32,768 Hz. Feed that to an electronic clock and you will have an atomic clock of sorts. Regards 9.8304 is 300 baud * 32768. So you can generate all the conventional digital data rates (1200,2400,.., 38.4k with powers of two). Typically, a UART wants to see a clock that is 16x or 8x bit time, so you need something a bit higher. ___ time-nuts mailing 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] Lady heather plus NTP server?
Chuck Forsberg WA7KGX wrote: I did a quick comparison between Lady Heather under Wine+Linux, Lady Heather under Win7, and WWV. The NTP time on my office machine agrees with WWV on 5 MHz as closely as my eyes and ears can tell. Linux is running its default NTP, Win7 is running Meinberg (as I recall). Windows is a lousy timekeeper, and the Windows port of the NTP software includes a number of workarounds for deficiencies in the Windows kernel. If the offset reported by ntpq -p on the Windows machine is more than just a few milliseconds then the following hints may be helpful. The latest Windows bug which came to our attention is that some Windows versions don't apply small time adjustments at all. For example, if NTP applies an adjustment less than 16 ticks to the Windows time this is simply ignored by Windows. However, NTP expects the adjustment to have some effect, but if there is no effect then the next time comparison yields a much larger difference than expected, and thus causes another adjustment which is probably larger than necessary. As a summary this can cause large swings in the time adjustment values. Newer developer version of the NTP package contain a workaround for this Windows bug. The report and fix are discussed here: NTP Bug 2328 - Vista/Win7 time keeping inaccurate and erratic https://bugs.ntp.org/show_bug.cgi?id=2328 The problem is also explained on the Microsoft support page: SetSystemTimeAdjustment May Lose Adjustments Less than 16 http://support.microsoft.com/kb/2537623 Even though the MS report only mentions Windows 7, the Windows Server 2008 kernel is similar to Windows 7 and has probably the same bug. So if you want to give it a try you can download a NTP developer version here which includes a workaround: http://support.ntp.org/people/burnicki/windows/ You should try the release version first. Just unzip the ZIP archive, stop the NTP service, copy all extracted files over the files in your NTP installation directory (e.g. C:\Program Files (x86)\NTP\bin\), and restart the NTP service. We have found that this version has greatly improved the resulting accuracy on Windows 7 and Windows Server 2008 installations. Please note under Windows you should configure all upstream servers with a line reading server aa.bb.cc.dd iburst minpoll 6 maxpoll 6 where aa.bb.cc.dd has to be replaced with the host name or IP address of your NTP server. Generally you should use a polling interval as short as possible under windows to let let ntpd apply adjustments quickly. However, please don't use polling intervals below 6 with the developer version since this prevents the workaround from working correctly as discussed in the bug report. Also, higher polling intervals can cause problems under Windows. See: NTP Bug 2341 - ntpd fails to keep up with clock drift at poll 7 http://bugs.ntp.org/show_bug.cgi?id=2341 So our advice is to use minpoll 6 maxpoll 6 as indicated in the example above. The patched ntpd has caused no drawbacks on any Windows machines, but has improved accuracy on a number of installations. Martin -- Martin Burnicki Senior Software Engineer MEINBERG Funkuhren GmbH Co. KG Email: martin.burni...@meinberg.de Phone: +49 (0)5281 9309-14 Fax: +49 (0)5281 9309-30 Lange Wand 9, 31812 Bad Pyrmont, Germany Amtsgericht Hannover 17HRA 100322 Geschäftsführer/Managing Directors: Günter Meinberg, Werner Meinberg, Andre Hartmann, Heiko Gerstung Web: http://www.meinberg.de ___ time-nuts mailing 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] PICPET- was Affordable (cheap) COTS (etc)
Brian, Well, my disciplining code is going to run as an FLL rather than a PLL to generate the correction for the OCXO or the Rb reference. The Propeller should work fine for a GPSDO. AFAIK no one has done this yet and I encourage you to try. The Parallax Propeller chip gets mentioned on the list once a year. Being an old Basic Stamp and SX guy, I have a soft spot for the Propeller too. Do you plan an external DAC or will you obtain high resolution with some sort of PWM-only solution? Maybe we should take this off-list while the QA is sorted out. Most people use a 5MHz crystal and the x16 PLL to clock the processors at 80MHz. I have been told that the Propeller will run at 100MHz just fine. My plans were to use the Propeller for a multi-channel, higher-resolution, time/frequency counter. As such the ADEV when the internal 16x PLL is enabled is of some interest. Then again, I should stop worrying and just measure it. I just thought that, while the PLL would have a bit more jitter, having the extra 3 bits of resolution would be useful in accumulating the error. Yes, I would agree. The only issue I can see with the Propeller is that once you complete your GPSDO you'd have a thousand times more interested users world-wide if you had done it with an Arduino or RPi. I'm not saying the Propeller isn't a unique and interesting chip, it's just that in the past 5 years Arduino and RPi (and others) have completely taken over the hobbyist world. The holy grail would be a turn-key Arduino GPSDO shield. Or Rpi GPSDO/NTP server. Anyway, let's take this off-list. If anyone else is interested, let me know too. Thanks, /tvb ___ time-nuts mailing 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] Nortel GPSDO osc age alarm
In a message dated 24/01/2014 21:48:27 GMT Standard Time, ail...@t-online.de writes: New ways of RF design - see photo ;-) - Definitely the last word in high rise developments:-) And glad to hear you got it sorted. Ok, I put three 1N4148 in series between DAC out and EFC in and a pull up of 4k7 up to 12V. It shifts the DAC voltage 1.8 volts up, so the osc is able to tune to 10MHz+3Hz. Locked! Now I can go back to the sofa, having a beer or two, being sweet again to my wife and my dog, :-) Thanks Volker Am 24.01.2014 17:49, schrieb Volker Esper: Thanks so much, Nigel, for this very interesting mail. Yes, the voltages are exactly as my ones. And yes, I've removed the oscillator, already. I then removed the thermal isolation from the osc, as well as the label, in slight hope for a hidden tuning screw. Of course, there isn't any. I, too, had this idea to level shift the EFC voltage. So I took seat at my computer to find out, which maximum EFC voltage would be ok. And saw your mail. Do you have any further information about the osc? The number on the sign (Trimble *0110-2450-T* *34310-T*) isn't really informative. By the way: When removing the big Trimble label I found a smaller one beneath, reading DOC2127 0101/1940; I think it's a Tekelc osc? Is there a pull-up resistor behind the EFC input pin so that I could use two diodes for level shifting? Or how did you? This part is more thrilling than I expected... Regards Volker Am 24.01.2014 12:08, schrieb gandal...@aol.com: Hi Volker One possibility, as I found with one of these recently, is that your oscillator has aged such that the required EFC voltage for 10MHz output is now outside the range provided by the board. The EFC behaviour can be tracked if Lady Heather is enabled from switch on and the DAC voltage monitored. The EFC voltage should start at 3 volts, in my case reported by LH as 3.02 Volts, and will sit at this level until enough satellites are being tracked for the board to decide it can start the conditioning process, at which point the DAC voltage will ramp upwards over the course of a few seconds until the point is reached where the oscillator frequency crosses 10MHz and the control loop takes over. All standard stuff of course but, as you've discovered, if the oscillator hasn't reached 10MHz by the time the EFC voltage reaches, in my case anyway, approximately 5.6 volts the board's OSC report switches to BAD and Normal OSC age switches to OSC age alarm and LH highlights both in red. The EFC voltage finishes its ramp at 6 Volts, reported as 6.04 Volts, and then just sits there, all exactly as you're seeing. Having removed my faulty oscillator, something that needs to be done VERY carefully to avoid damage to the board, I found that it required an EFC voltage of just under 6.6 Volts for the the output frequency to reach 10MHz. The seller, fluke.l, was very helpful as always and offered to supply a replacement 34310-T oscillator, this one did have it's required EFC voltage in the correct range and resolved the problem. However, whilst waiting for the replacement to arrive I left the original oscillator on test and monitoring it for a while suggested that the only thing wrong with it was the required EFC voltage, so I reconnected it to the board using a wired lash-up on the bench with a simple 2 Volt level shifter inserted into the control loop and did indeed get a locked condition with Lady H reporting the DAC voltage from the board as close to 4.5 volts. This suggests that whilst the board design requires the oscillator EFC Voltage at 10 MHz to be between 3 and 6 Volts an oscillator that falls outside this range shouldn't automaticall be assumed to be faulty in more general terms, although it's obviously getting a bit long in the tooth and that doesn't help much if it happens to be soldered into your circuit board ! Whilst it is possible to remove and replace the original oscillator there is an alternative to physical replacement, one which I've now implemented, and this uses the mounting positions already available beneath the oscillator, not usable though until it's removed, to fit a couple of SMA or SMB connectors. These two connectors couple the 10MHz signal from the oscillator into the board (J9) and the EFC Voltage out to the oscillator (J10). Although there is a regulated supply available from the oscillator, which might be expected to supply the EFC circuitry, in practice this connection does not seem to be required. I have not investigated further as yet to determine whether the board auto senses and uses this supply if it is present, or whether it always just ignores it, but it doesn't seem to be an issue
Re: [time-nuts] Nortel GPSDO osc age alarm
9.8304 MHz output, an odd frequency used by the cell tower equipment 9.8304 MHz is 8 x 1.2288 MHz which is the CDMA PN chip rate a rather fundamental frequency to the CDMA phone system Zim ___ time-nuts mailing 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] 1050A Oscillator configuration
Does anyone have experience with Datum 1050A output configurations. I have seen them loaded with everything from 1ea - 1PPS, 100KHz , 1MHz, 5MHz, and 10MHz to 4-10MHz and 1-5MHz to units with just a single 5MHz and 10MHz. I would like to switch one unit to 2-10MHz and 3-5Mhz or even 1-10MHz and 4-5MHz outputs. I know I can add and additional distribution amp but would rather know how the engineers originally obtained those outputs. Thanks Thomas Knox ___ time-nuts mailing 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] Z3815A receiver transplant
Hi all, The Z3815A is working perfectly with the new receiver except for a persistent antenna alarm. The new receiver is reporting the antenna is OK but it must have a different self-test answer sentence to the old one. The self-test is a PFEC sentence, which is proprietary to the manufacturer and not part of the standard NMEA protocol. It's responding appropriately to self-test requests from the motherboard but obviously there's a difference in the answer sentence which reports antenna integrity. I've tested it with two different antennas and they both see lots of sats properly but still produce that alarm. If anyone here has any documentation or manuals for the Furuno GT-74 I would be very grateful for copies. If I can find the reason for the persistent alarm and it's a difference in the self-test answer, I'll make up a new interface with a microcontroller to emulate the old receiver and then it will be indistinguishable! Morris VK3DOC in Melbourne, Australia ___ time-nuts mailing 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] high (spacial) precision GPS in Kickstarter
http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-gps-receiver Has anyone seen this? Any time-nuts utility? Daniel ___ time-nuts mailing 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] high (spacial) precision GPS in Kickstarter
Hello Daniel, Appears that is precision for position - not necessarily time. I think NIST had a write-up on something very similar. Regards, John Westmoreland On Fri, Jan 24, 2014 at 5:40 PM, Daniel Mendes dmend...@gmail.com wrote: http://www.kickstarter.com/projects/swiftnav/piksi-the-rtk-gps-receiver Has anyone seen this? Any time-nuts utility? Daniel ___ time-nuts mailing 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] Z3815A receiver transplant
Hi Morris, You should be able to bridge one of the TTL to RS-232 ports on a MAX232 onto the line from the Z3815A to the GT-8031. This will let you capture the commands the Z3815A sends by using any terminal program. Similarly, if you bridge onto the line from the GT-8031 to the Z3815A you can capture the responses. I did that while investigating a problem with my Z3801A. Ed On 1/24/2014 5:17 PM, Morris Odell wrote: Hi all, The Z3815A is working perfectly with the new receiver except for a persistent antenna alarm. The new receiver is reporting the antenna is OK but it must have a different self-test answer sentence to the old one. The self-test is a PFEC sentence, which is proprietary to the manufacturer and not part of the standard NMEA protocol. It's responding appropriately to self-test requests from the motherboard but obviously there's a difference in the answer sentence which reports antenna integrity. I've tested it with two different antennas and they both see lots of sats properly but still produce that alarm. If anyone here has any documentation or manuals for the Furuno GT-74 I would be very grateful for copies. If I can find the reason for the persistent alarm and it's a difference in the self-test answer, I'll make up a new interface with a microcontroller to emulate the old receiver and then it will be indistinguishable! Morris VK3DOC in Melbourne, Australia ___ time-nuts mailing 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] Small DPM clocks
List, What I am looking for is a way to display Local Time (MST) and Zulu (GMT) time in a small (6 X 8 or similar) package. There must be two displays and both lock up to NBS. Has anyone seen such a thing? Hi Martin, If you look on Ebay and type in LED automobile clocks, there is a large selection of DPM units that might meet your needs. Regards, Perrier ___ time-nuts mailing 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] Z3816A Control and Cleaning
All, I had already set the local time zone offset from GPS to '0' so I can't address the success or not of the following commands if the 'offset' has not been set to '0'. :DIAG:GPS:UTC 1 Worked great to set the system from GPS time to UTC time. However, nothing changed on the display until I hit: *tst? That set the ALARM for a few seconds then the receiver 'reset'. It had to re-acquire satellites which took a while but it came up with GPS LOCK and displaying UTC time. If you send: :DIAG:GPS:UTC? It will return '1' for UTC or '0' for GPS, depending on what the Z3816A is set for. -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Donald Henderickx Sent: Friday, January 24, 2014 9:57 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816A Control and Cleaning On 1/23/2014 11:30 PM, Hal Murray wrote: Also, I seem to recall a command that can be sent by SatStat to change from GPS time to UTC time but I can't find it in my files. Is there such a command or am I hallucinating? My notes for the Z3801A say: :diag:gps:utc 1 http://www.realhamradio.com/GPS_User_Notes.htm (undocumented) My Z3801 notes which came from Bill Jones K8CU show the same however in upper case. I added a note that it did not work until local time zone was set to 0hrs 0min. Don H ___ time-nuts mailing 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] Z3816A Control and Cleaning
Larry, Thanks for the education. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid Sent: Friday, January 24, 2014 12:21 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816A Control and Cleaning Oops! RO is Reverse Osmosis. I incorrectly assumed that was widely known. I've had an RO system under my kitchen sink for 30 years. Even CostCo sells RO systems you can install yourself. There is a separate spigot faucet on the sink for this mineral-free water. RO systems first pass city water through a fine particle filter, then allow only pure water to pass through an osmotic membrane into a low-pressure storage tank. Before delivery out the separate spigot, that RO water is passed through an activated carbon filter. All this hardware resides on a smallish vertical platform under your kitchen sink. Here in Anaheim, California, where all water is imported directly or indirectly, the mineral content is relatively high. I maintain my RO system carefully and monitor how it performs by measuring the water conductivity, which is commonly referred to in water reports as Dissolved Solids in ppm (parts per million). My city tap water measures between 600 and 800 ppm dissolved solids (and, sometimes higher); my RO system delivers water at 8-12 ppm. True distilled water will measure 0-2 ppm dissolved solids so RO is almost as good, good enough to not make a difference for our purposes, except perhaps in the highest imaginable high-impedance or high-voltage circuits. So, what is it that causes the high dissolved solids content of tap water? It is *salt* in one form or another, generally magnesium and calcium salts, and can include common sodium chloride (table salt). Salt is electrically conductive so measuring water conductivity is a common way to evaluate mineral content. Many years ago a company named Myron-L established and made popular an assumed mixture of salts found in tap water and calibrated water conductivity in dissolved solids. This assumed mixture and reporting in dissolved solids remains popular today. You likely get a water purity report from your local water supplier; look in there and you will find dissolved solids reported in ppm. You may also find specific minerals reported but that is not done by conductivity. Sometimes you see conductivity reported as conductivity (reciprocal of resistance), with no attempt to convert to a dissolved solids percentage. Think of taking a 5 gallon jug of distilled water and adding a teaspoon of table salt. Would you want to drench your electronics with that water? You'll never get all the water blown out or drained out; what water remains will evaporate. What remains after evaporation is the minerals or salt. Not good to have salt on your circuit boards! It is difficult to harm any electronics by drenching them with distilled or RO water. What does not immediately drain out simply evaporates over time but leaves behind no mineral salt and causes no problem. Drop your cell phone into a lake? Immediately soak it in distilled water to dilute the salt in the lake water. Spill coffee on your keyboard? Drench it with distilled water and let it dry. Let anything you get wet, dry thoroughly before re-applying power! Use slightly elevated temperature to accelerate evaporation. Ever wonder what causes water spots on glassware you don't dry with a towel? Those spots are simply mineral salts left when the city tap water evaporates. I often hand wash a few dishes in my kitchen, but then I rinse them with RO water from the convenient sink-top spigot and let them drain dry. Guess what? No water spots because there are no significant minerals in the RO water. Some homes have soft or deionized water provided by a de-mineralizer that uses salt. The result varies widely and this so-called soft water is not mineral-free. Some will use this water for electronic cleaning; I will not and instead use my RO water, which I monitor and know how mineral-free it really is. Want to check your own tap water for dissolved solids? Easy and cheap today. Search eBay for Dissolved Solids Meter and you will find many hand-held, battery powered LCD meters offered for about $10-$12. RO water is convenient and has other uses around the home. We recently suffered a period of very low relative humidity (5%) and I started using an ultrasonic nebulizer humidifier in my bedroom. I fill it with RO water from my kitchen sink and as a result have no mineral powder falling out of the humidified fog. Do any metal finishing at home? I always use only RO water to avoid unexpected results from tap water. Do you enjoy hot tea? Tanic acid in tea is a mineral indicator and tea made with hard water will be very dark in color. Use RO water and the tea will be amber and taste better. Same with coffee... My RO system gets a lot use! Larry On 1/24/2014 9:12 AM, J. L. Trantham wrote: Larry,
[time-nuts] FS: HP-10811 variant....
I need to clean the ham-shack here... I have one of these HP-10811 variants that I posted about last week that I'm willing to part with. It is marked HP-05071-60219. It is a single oven version. It has been tested and works . Make me an offer above $60 and it is yours plus shipping. (USPS is best for domestic sale) Is it worth $60??? Based on e-pay prices that are all over the place, I think it's a valid first try. Please reply off-list. First one wins. Thanks for the BW. Regards, -Brian, WA1ZMS/4 Forest, VA ___ time-nuts mailing 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] Lady heather plus NTP server?
Further to Martin's most helpful comments, you can see how well Windows performs as an NTP server here: http://www.satsignal.eu/mrtg/performance_ntp.php#windows and as a stratum-1 server here: http://www.satsignal.eu/mrtg/performance_ntp.php#windows-stratum-1 There's quite a lot of difference over the versions, with Windows 8/8.1 having the potential to be the best performer as it has a more precise get system time function. For the convenience of Windows users who can't or prefer not to compile their own versions (although the tools are free and available), I keep a few recent executables here: http://www.satsignal.eu/ntp/x86/ Just stop the NTPD service, copy the executables, and restart the service. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
