Re: [time-nuts] PM6685 GPIB PROM image ?
Yes, I'm finishing rebuilding the PM6685 from a couple of part units, then I'll try to use the GPIB card as is, but since the service manual specifies clearly that the GPIB ROM FW version must match the mainboard ROM FW version I do not expect it to work, as the current GPIB ROM is clearly marked 9626/80 V1.12C, so it is likely specific for the 6680 and there is probably a SW check for the correct ROM version at power- on. Regards, Claudio Original Message From: azelio. bori...@screen.it Date: Aug 27, 2012 12:07 AM To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subj: Re: [time-nuts] PM6685 GPIB PROM image ? First try if it works as it is. On Sun, Aug 26, 2012 at 11:24 PM, Claudio Girardi claudio. gira...@virgilio.it wrote: Hello, I have a GPIB option card (PM9626) from a PM6680 and I would like to use it in a PM6685. Looking at the service manuals, the only difference between the two GPIB cards for the two counters is the FW PROM, so I'm looking for a PM6685 GPIB PROM image or anybody with a PM6685 that could help with this. Thanks!, Claudio ___ time-nuts mailing 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] newbie question Thunderbolt supply
Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] newbie question Thunderbolt supply
Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] newbie question Thunderbolt supply
Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd 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] newbie question Thunderbolt supply
Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] newbie question Thunderbolt supply
On 08/27/2012 10:09 AM, Jerry wrote: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly A layer of Kapton (polyimide) tape would be electrically insulating but still conduct heat well enough for this application. You could then put a thermal pad under that and not have to worry about it being conductive or (I think) capacitative. I'd prefer the pad to the grease because the bottom of a PCB has lots of pointy bits that would keep the plane of the PCB spaced away from the plate, and thermal grease is not very effective as a filler material. It would also be springy enough to maintain contact with the bottom of the PCB. I'm still not entirely sure this is a good idea though, seems like a low-temp oven for the whole tbolt would be better if you want thermal stability. -- m. tharp ___ time-nuts mailing 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] newbie question Thunderbolt supply
There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] FW:
Hi friend! http://jesusmylifechurch.org/poganini112.html?dtopicid=1ynuo ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt temperature
Michael wrote: I'm still not entirely sure this is a good idea though, seems like a low-temp oven for the whole tbolt would be better if you want thermal stability. Precisely because it is not clear that holding the backplate of a Tbolt at a constant temperature is the best way to keep the interior of its crystal oven at the most constant temperature (which is the ultimate goal), I mounted mine on thermally insulating standoffs in a cast aluminum box with about 1 of clearance on all sides, and control the air temperature inside the cast box. For another Tbolt mounted similarly, I control the surface temperature of the cast box, which seems to work equally well. In both cases, I adjust the controller for whatever measured temperature produces a Tbolt internal temperature reading (via the Tbolt's DS1620) of about 45C -- safely above any ambient temperature to which the mounted units will be exposed, to avoid the need for active cooling (Peltier, etc.), but not excessively so, to keep the internal electronics as cool as is practicable. 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] newbie question Thunderbolt supply
Sorry I thought the discussion was about the bottom case of the TBolt, not the PCB, being in contact with a larger thermal mass. jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 10:44 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Wireless Mesh Network Time Server
Apparently the synchronization requirements are within a few seconds. Wireless mesh process value transmitters have taken over the process control industry. Some users require millisecond accuracy for the time stamp on any alarm of event messages the device may send. Seems like that would be a challenge for a reconfigurable network. Bill Hawkins -Original Message- From: Raj Sent: Monday, August 27, 2012 10:18 AM From Elektor, Sept. 2012 https://dl.dropbox.com/u/10377704/Mesh%20EE.jpg ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] newbie question Thunderbolt supply
On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote: te and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren What happens if you flood the entire assembly in transformer oil? Aside from making a mess. Or look here: Thermal-Thermal_Pads_Tapehttp://www.frozencpu.com/cat/l2/g8/c487/list/p1/Thermal-Thermal_Pads_Tape.html -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Need usb time interval time for portable bullet chrongraph
Hi All of the good stuff in a chrono is in the trigger part of it. Even with very well designed triggers, there is a lot of ambiguity (by Time Nut standards) in the measured time of flight. A simple time base and counter is way more than adequate for the digital end of the device. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Monday, August 27, 2012 1:52 AM To: Paul Cianciolo; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Need usb time interval time for portable bullet chrongraph Hi Paul: I'm presently adapting a chrony chronograph because I want to use the triggers for timing and other purposes. They've spent a LOT of engineering time to get proper triggering, and the triggers can easily be pulled off without disturbing the basic unit. The triggers are robust and will drive a piece of coax with a nice pulse at a 5 v level. The cheapest chrony is under $100 and using their triggers will save you HOURS and HOURS of fiddling around, trust me! You can use something like an arduino which has two interrupt inputs to do the time measurement, or as Tom suggests. Don Paul Cianciolo Hello Folks I have been looking at bullet chrographs and wondering if I could get the a usb module to do a interval measurement and display on my laptop. on a yet to be discovered module to calculate the time interval between the pulses? The bullet travels at approx 1050 feet per second. By spacing my gates providing the start stop pulses precisely 1 foot apart I think a direct read out except for the decibal point being in the wrong place . Does this seem fesable? Here is one module I found http://www.weedtech.com/index_eventcount.html Any thoughts on this? The reason for the USB would be for display on my laptop at the firing range Thank you for any help I would really appreciate it 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Need usb time interval time for portable bullet chrongraph
USB is a serial protocol and has some latency issues. I am also involved with CNC machining and this has caused some issues in the past. (the 'standard' is to use a parallel port or two) The work around is to offload the timekeeping functions to an external box and just use the USB to transfer data. Your chrony could store the times and then transfer the session data to the 'puter through the USB port. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Sunday, August 26, 2012 22:52 To: Paul Cianciolo; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Need usb time interval time for portable bullet chrongraph Hi Paul: I'm presently adapting a chrony chronograph because I want to use the triggers for timing and other purposes. They've spent a LOT of engineering time to get proper triggering, and the triggers can easily be pulled off without disturbing the basic unit. The triggers are robust and will drive a piece of coax with a nice pulse at a 5 v level. The cheapest chrony is under $100 and using their triggers will save you HOURS and HOURS of fiddling around, trust me! You can use something like an arduino which has two interrupt inputs to do the time measurement, or as Tom suggests. Don Paul Cianciolo Hello Folks I have been looking at bullet chrographs and wondering if I could get the a usb module to do a interval measurement and display on my laptop. on a yet to be discovered module to calculate the time interval between the pulses? The bullet travels at approx 1050 feet per second. By spacing my gates providing the start stop pulses precisely 1 foot apart I think a direct read out except for the decibal point being in the wrong place . Does this seem fesable? Here is one module I found http://www.weedtech.com/index_eventcount.html Any thoughts on this? The reason for the USB would be for display on my laptop at the firing range Thank you for any help I would really appreciate it 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] newbie question Thunderbolt supply
Hi It's probably easier to put the TBolt inside a sealed box along with a small /low speed / quiet fan. Let the moving air equalize everything. If vibration is a concern, mount the fan on some sort of isolators. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Monday, August 27, 2012 12:02 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] newbie question Thunderbolt supply On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote: te and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren What happens if you flood the entire assembly in transformer oil? Aside from making a mess. Or look here: Thermal-Thermal_Pads_Tapehttp://www.frozencpu.com/cat/l2/g8/c487/list/p1/Th ermal-Thermal_Pads_Tape.html -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] newbie question Thunderbolt supply
There are thermal pads that are thermally conductive. You typically see them in laptops and, oddly, optical drives. They're usually one or two mm thick and very soft and squishy. Pull the bottom plate off any full-size optical drive and you'll probably find one or two pieces. I see lots of them on the auction site, but I have no personal experience with those. It looks like there's at least one or two that are available in large pieces and I saw thicknesses from 0.4mm up to 4.0mm. I wouldn't expect these to move heat nearly as well as a thin layer of thermal grease (which is itself a thermal insulator), but for some applications it works and is the only practical solution. Ed On 8/27/2012 10:12 AM, Bob Camp wrote: Hi The pad stuff is normally an insulator. It's not very stable, so there may be better alternatives. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 10:44 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply There are components and traces. Bert In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time, jster...@att.net writes: Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Wireless Mesh Network Time Server
If the article is accurate, then it's not a real time server, pushing out the time at regular intervals. I started on a similar project, using GPSD and NTPD on a WRT54G. I had problems getting all the various modules to cooperate on OpenWRT. I'll revisit the project when I have time and see if I can't make it all play nice. Joe Gray W5JG On Mon, Aug 27, 2012 at 10:01 AM, Bill Hawkins b...@iaxs.net wrote: Apparently the synchronization requirements are within a few seconds. Wireless mesh process value transmitters have taken over the process control industry. Some users require millisecond accuracy for the time stamp on any alarm of event messages the device may send. Seems like that would be a challenge for a reconfigurable network. Bill Hawkins -Original Message- From: Raj Sent: Monday, August 27, 2012 10:18 AM From Elektor, Sept. 2012 https://dl.dropbox.com/u/10377704/Mesh%20EE.jpg ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Need usb time interval time for portable bullet chrongraph
amen to that, brother Bob! Don Bob Camp Hi All of the good stuff in a chrono is in the trigger part of it. Even with very well designed triggers, there is a lot of ambiguity (by Time Nut standards) in the measured time of flight. A simple time base and counter is way more than adequate for the digital end of the device. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Don Latham Sent: Monday, August 27, 2012 1:52 AM To: Paul Cianciolo; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Need usb time interval time for portable bullet chrongraph Hi Paul: I'm presently adapting a chrony chronograph because I want to use the triggers for timing and other purposes. They've spent a LOT of engineering time to get proper triggering, and the triggers can easily be pulled off without disturbing the basic unit. The triggers are robust and will drive a piece of coax with a nice pulse at a 5 v level. The cheapest chrony is under $100 and using their triggers will save you HOURS and HOURS of fiddling around, trust me! You can use something like an arduino which has two interrupt inputs to do the time measurement, or as Tom suggests. Don Paul Cianciolo Hello Folks I have been looking at bullet chrographs and wondering if I could get the a usb module to do a interval measurement and display on my laptop. on a yet to be discovered module to calculate the time interval between the pulses? The bullet travels at approx 1050 feet per second. By spacing my gates providing the start stop pulses precisely 1 foot apart I think a direct read out except for the decibal point being in the wrong place . Does this seem fesable? Here is one module I found http://www.weedtech.com/index_eventcount.html Any thoughts on this? The reason for the USB would be for display on my laptop at the firing range Thank you for any help I would really appreciate it 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. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] PM6685 GPIB PROM image ?
Hi Claudio, I have inquired with the factory if they can provide the PROM. The contents of that PROM have not changed since 2003 so we should be able to provide one. They are on holiday today so when I hear something, I will let you know. On Mon, Aug 27, 2012 at 4:18 AM, Claudio claudio.gira...@virgilio.itwrote: Yes, I'm finishing rebuilding the PM6685 from a couple of part units, then I'll try to use the GPIB card as is, but since the service manual specifies clearly that the GPIB ROM FW version must match the mainboard ROM FW version I do not expect it to work, as the current GPIB ROM is clearly marked 9626/80 V1.12C, so it is likely specific for the 6680 and there is probably a SW check for the correct ROM version at power- on. Regards, Claudio Original Message From: azelio. bori...@screen.it Date: Aug 27, 2012 12:07 AM To: Discussion of precise time and frequency measurementtime-nuts@febo.com Subj: Re: [time-nuts] PM6685 GPIB PROM image ? First try if it works as it is. On Sun, Aug 26, 2012 at 11:24 PM, Claudio Girardi claudio. gira...@virgilio.it wrote: Hello, I have a GPIB option card (PM9626) from a PM6680 and I would like to use it in a PM6685. Looking at the service manuals, the only difference between the two GPIB cards for the two counters is the FW PROM, so I'm looking for a PM6685 GPIB PROM image or anybody with a PM6685 that could help with this. Thanks!, Claudio ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] /Agilet counter 53131A (not 53151A) trigger problems
Try switching the 50 ohm input impedance in and out a couple of times. This has worked for me more than once in the past. I think it may be a sticking relay or dirty contacts, etc. Rich Stolte AccuSource Electronics I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ 08/27/12 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice of authority nor the weight of reason and argument are as significant as experiment, for thence comes quiet to the mind. R. Bacon If you don't know what it is, don't poke it. Ghost in the Shell Dr. Don Latham AJ7LL Six Mile Systems LLP 17850 Six Mile Road POB 134 Huson, MT, 59846 VOX 406-626-4304 www.lightningforensics.com www.sixmilesystems.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
[time-nuts] What are HP High Stability Oscillators (Option 1D5 in 8720D VNA)
I recently bought an HP 8720D 20 GHz VNA with options 010 (TDR facility) and 1D5, which is the high stability time base. It's a fairly old VNA (not supported since 2004), but it's not exactly a dinosaur Accuracy (23 deg C +/- 3 deg C) 10 ppm The standard oscillator specs are: Stability 0 - 55 deg C 7.5 ppm Ageing per year = +/-3 ppm The high stability time base, option 1D5 are: Stability 0 - 55 deg C +/- 0.05 ppm Ageing +/- 0.5 ppm Resolution 1 Hz. What is likely to be the difference in design between the standard and high stability oscillators? It seems that while the optional timebase is more stable, this does not appear to reflect in the accuracy of the instrument, which is specified as 10 ppm. Perhaps that's due to the fact that the steps are 1 Hz, and the synthesiser can't generate exactly 1 Hz steps. I don't know. You guys know more than me! dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Need usb time interval time for portable bullet chrongraph
However, since we are all nuts here, adding a GPSDO coulnt' hurt. (Usually you shoot outside, so access to the sky should be easy!) Then you'd also know position, which could be useful in accounting for numerous other thing like coriolis acceleration, gravity due to elevation, and gravity anomalies You could then calculate corrections for trajectories... hmmm... On 8/27/2012 12:12 PM, time-nuts-requ...@febo.com wrote: Hi All of the good stuff in a chrono is in the trigger part of it. Even with very well designed triggers, there is a lot of ambiguity (by Time Nut standards) in the measured time of flight. A simple time base and counter is way more than adequate for the digital end of the device. Bob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Isotemp OCXO trimpot question...
I have an Isotemp OCXO (674-0010-000) an am wondering what is the recommended value for the frequency trim pot? Bud W0LCP Time is only there to prevent everything from happening at once. Einstein ___ time-nuts mailing 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] Shera PIC Firmware file
Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What are HP High Stability Oscillators (Option 1D5 in 8720D VNA)
On 08/27/2012 10:14 PM, David Kirkby wrote: I recently bought an HP 8720D 20 GHz VNA with options 010 (TDR facility) and 1D5, which is the high stability time base. It's a fairly old VNA (not supported since 2004), but it's not exactly a dinosaur Accuracy (23 deg C +/- 3 deg C) 10 ppm The standard oscillator specs are: Stability 0 - 55 deg C 7.5 ppm Ageing per year = +/-3 ppm The high stability time base, option 1D5 are: Stability 0 - 55 deg C +/- 0.05 ppm Ageing +/- 0.5 ppm Resolution 1 Hz. What is likely to be the difference in design between the standard and high stability oscillators? It seems that while the optional timebase is more stable, this does not appear to reflect in the accuracy of the instrument, which is specified as 10 ppm. Perhaps that's due to the fact that the steps are 1 Hz, and the synthesiser can't generate exactly 1 Hz steps. I don't know. You guys know more than me! AT-cut TCXO vs. SC-cut OCXO maybe? A common diffrentiation. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Need usb time interval time for portable bullet chrongraph
On 08/27/2012 10:28 PM, Dan Kemppainen wrote: However, since we are all nuts here, adding a GPSDO coulnt' hurt. (Usually you shoot outside, so access to the sky should be easy!) Then you'd also know position, which could be useful in accounting for numerous other thing like coriolis acceleration, gravity due to elevation, and gravity anomalies You could then calculate corrections for trajectories... hmmm... I got an old Meinberg GPS, with an analogue integrating single-channel receiver, and put at a friends appartment. Still works great, after me convincing it about a new location. It has two time-tagging inputs, so you can get UTC time-stamps with 100 ns resolution of the serial port. With a good trigger and then a serial adapter... you got some cool time-stamping good enough for the purpose I guess. :) Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Datum/FTS 1000B and 1130 oscillator
Hi; Has anyone compared the 1130 and 1000B. Are they plug and play interchangeable as far as VC. I have a few data sheets that spec each differently. It looks like the 1000B has better Close in Phase Noise and the 1130 has better long term stab. 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.
Re: [time-nuts] Shera PIC Firmware file
Ron, Here is Mr. Shera's actual web page on the topic. At the bottom you will find the HEX file file for the firmware. Don't ask as there is no published assembly listing of the firmware. Mr. Shera does not feel like releasing it to the general public at this time. Also, on that page is a link to the original article he wrote on the project. So it is a good page to bookmark. BillWB6BNQ Ron Ward wrote: Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
My starting point is the paper by Neubig on the real vs. predicted aging: experimenting with the model and try to cut it around the Morion or the Oscilloquartz OCXOs. On Tue, Aug 28, 2012 at 12:15 AM, Don Latham d...@montana.com wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Neither the voice
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. The goal wasn't to turn a quartz oscillator into an atomic clock replacement, but simply to get the oscillator through a 1 hour or so holdover time during GPS outages. It sort of worked for that very limited purpose, but in general, past performance of HP crystals wasn't a very good predictor of future results. Crystals would age in one direction for a while and possibly slow down as time when on, but then then might start aging in the other direction. There were also frequency jumps that were substantial and totally random. The reason why the HP crystals were unpredictable was that all the deterministic processes such as mass preferentially depositing on the crystal, so as to make the frequency age lower, had been eliminated by years of manufacturing improvements. The remaining processes were of the nature of quartz stress relaxation that were very random. Rick Karlquist Don Latham wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
[time-nuts] {OT} e-mail testing only....
Just testing. My cloud/web based ATT e-mail address book was hacked. ATT now has e-mail servers run by Yahoo. Drat! Yahoo has a gaping security hole. My PW was not hacked, but my address book in cloud storage was used to send out spam. It was not a full copy of my real address book, but enough to cause me much damage control effort today. All PWs have been changed yet again to be sure, but the cloud address book has also been deleted. So much for web- based or cloud based address books. Back to local PC and iPhone only address books for me. No iCloud either. MY DEEPEST AND SINCERE APPOLOGIES TO ALL! I am embarrassed. My first and only hack in 20+ years of e-mail. So I guess I was overdue. Yahoo/ATT today. When will G-Mail get hit? :- ) Life in a modern spam rich world. 73, -Brian, WA1ZMS (If you don't see this signature line, it's not me. Just delete it please.) ___ time-nuts mailing 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] Isotemp OCXO trimpot question...
I tried to attach to this email a datasheet for a very similar Isotemp 10Mhz OCXO (Model OCXO134-10; PN 6624.2) the time-nuts server will not let me. I am not certain whether the pins are the same as your model but I believe all the Isotemp OCXO have same arrangement: 3. ELECTRICAL FREQUENCY ADJUSTMENT 3.1. Range ±0.45 PPM ±1.2 PPM (At time of shipment) (Referenced to nominal frequency) 3.2. Control0 VDC to Vref (0 VDC to +8 VDC ) or a 10 kW potentiometer connected between pins 2 and 4 with wiper connected to pin 3. 3.3. Slope Positive 3.4. Center Vref/2 ±10% of Vref (+4 VDC to +0.8 VDC) Jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Azelio Boriani Sent: Monday, August 27, 2012 6:57 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Isotemp OCXO trimpot question... If there is no datasheet to refer to then the usual value is between 10K and 20K. 10K is the most common value for 5V or 8V Vref. The OCXO should provide the Vref output pin to connect one side of the pot, the other to GND, for a GND referenced EFC. Your mileage may vary but, without a datasheet, it is the best starting point. On Mon, Aug 27, 2012 at 11:26 PM, Bud Patten bud.pat...@frontiernet.netwrote: I have an Isotemp OCXO (674-0010-000) an am wondering what is the recommended value for the frequency trim pot? Bud W0LCP Time is only there to prevent everything from happening at once. Einstein ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] HP/Agilet counter 53131A (not 53151A) trigger problems
Could you refresh me with the reference or email the paper? I'd like to give it a read. Don Azelio Boriani My starting point is the paper by Neubig on the real vs. predicted aging: experimenting with the model and try to cut it around the Morion or the Oscilloquartz OCXOs. On Tue, Aug 28, 2012 at 12:15 AM, Don Latham d...@montana.com wrote: There are ways of generating models, such as ARIMA, using past behavior and the models used to tweak filters and so on. The shifts would have to be accounted for as they occur, seems to me. Now the interesting possibility is that a shift does not alter the underlying model for a given crystal Has to be tested. Don Azelio Boriani So it can't be done... the possibility to discipline an OCXO taking the action from a suitable model should help in speeding up the adjustments and avoiding the humps as seen in the Allan deviation plot. On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote: Isn't crystal aging marked by random jumps? perhaps lattice rearrangement? Really hard if not impossible to model... Don Azelio Boriani 30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for that input. I have the 53132A and the 53181A so I can test (with the RS SML01). Is this problem new? Never tested before? About the OCXO aging: OK, I'm interested in the development of a model that can be general enough so that it can be steered, adjusting its parameters, during the OCXO life. The data (to adjust the parameters) will be gathered by the continuous monitoring with the GPS. On Mon, Aug 27, 2012 at 7:01 PM, Bernd Neubig bneu...@t-online.de wrote: Hi Azelio, Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV (rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz. The problem can be at either input alone. The problem is only in the range between 100 MHz and 200 MHz, observed in automatic trigger mode. In manual trigger mode the counter does not trigger at all in that freq range. I cannot tell you an aging model for a particular OCXO, and I doubt if anyone can ;) Aging predictions can only be made on individual OCXO, unit by unit, and the prediction is only valid over a rather limited time. Therefore you must continuously monitor and update your prediction. Best regards Bernd DK1AG -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Azelio Boriani Gesendet: Freitag, 24. August 2012 17:28 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] HP/Agilet counter 53151A trigger problems From the datasheet: A input 10Hz..125MHz min level 25mVrms (-19dBm) B input min 50MHz, -20dBm the problem is on A input only? Maybe 150MHz for the A input, being beyond the official specifications, requires more signal on one counter than the other. In the past they all were fine? I have read your paper on the correlation between the real and predicted aging of crystal oscillators. I'm trying to find a suitable model for the Morion MV201 OCXO or the Oscilloquartz 8663 to implement a Kalman filter. On Fri, Aug 24, 2012 at 3:34 PM, Bernd Neubig bneu...@t-online.de wrote: Hi all, I have several HP/Agilent frequency counters 53151A (and 53152A) in my lab. Several of them meanwhile show trigger problems. I have tested the A and B channel between 5 MHz and 200 MHZ at three input levels of -10 dBm, 0 dBm and +10 dBm. Those with trigger problems show erroneous numbers at -10 dBm input level rather selectively, i.e. mostly at 100 MHz, some also at 150 MHz, while the are o.k. Has anyone on this list experienced similar defects and can give a recommendation how to fix/repair them? Best regards Bernd DK1AG www.axtal.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] newbie question Thunderbolt supply
The thermal pads are, generally, electrically 'insulative' but heat 'conductive'. However, the screws that are usually used to mount the TBolt are metal and conduct electricity. Therefore, the main focus should be to transfer heat for the purpose of keeping the TBolt at a constant temperature. The transfer of electricity is secondary. The screws provide DC and AC conductivity and the pads augment AC conductivity. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Jerry Sent: Monday, August 27, 2012 9:09 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] newbie question Thunderbolt supply Are these thermal pads temp conductive or insulative? If you want heat dissipation why not use the readily available thermal grease used for semiconductor mounting? Cheap and not really messy if applied correctly jerry -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of ewkeh...@aol.com Sent: Monday, August 27, 2012 9:38 AM To: time-nuts@febo.com Subject: Re: [time-nuts] newbie question Thunderbolt supply Thank you. Will look for it here under thermal pad. Bert In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time, azelio.bori...@screen.it writes: Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)... On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote: Chris Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V 6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding the backplate temp constant and total power goes up to 7.6 W since the oven has to work harder. T bolt, switchers and all regulators are on the other side of the 3/32 Alu plate. The AC switcher is not included in the power numbers. but is also on the plate. Plate is held at 40 C. I am looking for a way to more closely couple the Tbolt circuit board to the back plate and am looking for the material switchers use between semiconductor and cooling plate Any one know where I can buy it in sheet form? Bert Kehren -Original Message- From: Chris Albertson albertson.ch...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sun, Aug 26, 2012 12:31 pm Subject: Re: [time-nuts] newbie question Thunderbolt supply On Sun, Aug 26, 2012 at 3:46 AM, ewkeh...@aol.com wrote: Having played with several solutions I found the best is a 12 V 1 A switcher with the output voltage increased to 15 V, check the capacitors and if necessary replace with 25 V. I laid out a PC board that has a TC7662A inverter followed by a 79L12. Also on the board is a 7812 followed by a 7805. Putting them in series gives me good thermal distribution. ne of the advantages of generating waste heat like that is that you can ut the heat to good use. I build a temperature controlled fan. It is ery simple a temperature sensor IC connects to an opamp that drives a ower transistor that drives a 12V fan. As for the power supply. I used a filter that does not drop any volts and can't see any RF on the DC using my old 365 Tek scope or by using a more ensitive RF power meter. hris Albertson edondo Beach, California __ ime-nuts mailing list -- time-nuts@febo.com o unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts nd follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Differences between the Datum/FTS 1000B and 1130 oscillator?
Hi; I am thinking of upgrading from a 1130 to a 1000B as a disciplined clean up oscillator. As I look into this it appears the 1130 has an electronic tuning range of 2-8vdc for +/-2E8. I cannot fine exact details on the 1000B, there appears to be a opt 505 with a 0-10vdc range 506 with a +/- 10vdc control range but there is no tuning range listed. Does anyone have any insight as to tuning range on the 1000B? Also does anyone know about other differences between the Datum 1000B and 1130? Thanks; Thomas Knox From: act...@hotmail.com To: time-nuts@febo.com Date: Mon, 27 Aug 2012 15:47:18 -0600 Subject: [time-nuts] Datum/FTS 1000B and 1130 oscillator Hi; Has anyone compared the 1130 and 1000B. Are they plug and play interchangeable as far as VC. I have a few data sheets that spec each differently. It looks like the 1000B has better Close in Phase Noise and the 1130 has better long term stab. 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 mailing 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] Datum Lamp Voltage
Hi, I'm just powering a new to me Datum Rb, Type 102500-001, LPRO for the first time. The unit locks up quickly, and after about an hour, I checked the Lamp voltage. My unit is sitting at 6.9 VDC. From the manual on Didier's site, below 3.0 or over 14 indicate failure. Does anyone know whether the measured voltage should be for a new unit? I'm trying to guestimat the remaining life. Thanks, -John ___ time-nuts mailing 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] Shera PIC Firmware file
Hi Bill: Okay, Thanks! Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of WB6BNQ Sent: Monday, August 27, 2012 3:16 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Shera PIC Firmware file Ron, Here is Mr. Shera's actual web page on the topic. At the bottom you will find the HEX file file for the firmware. Don't ask as there is no published assembly listing of the firmware. Mr. Shera does not feel like releasing it to the general public at this time. Also, on that page is a link to the original article he wrote on the project. So it is a good page to bookmark. BillWB6BNQ Ron Ward wrote: Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing 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] Datum Lamp Voltage
John only indirectly from other RBs and they are FRS's. They start off higher 8-11 or so volts then come down to a lower value and sit there for a long time. I would think you are mid to early life. More towards the mid. But thats good for quite a few years. Regards Paul WB8TSL On Mon, Aug 27, 2012 at 9:33 PM, J. Forster j...@quikus.com wrote: Hi, I'm just powering a new to me Datum Rb, Type 102500-001, LPRO for the first time. The unit locks up quickly, and after about an hour, I checked the Lamp voltage. My unit is sitting at 6.9 VDC. From the manual on Didier's site, below 3.0 or over 14 indicate failure. Does anyone know whether the measured voltage should be for a new unit? I'm trying to guestimat the remaining life. Thanks, -John ___ time-nuts mailing 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] LORAN ... Any News?
A friend emailed me that the North Koreans jammed GPS in May. See: http://arstechnica.com/information-technology/2012/05/north-korea-pumps-up-the-gps-jamming-in-week-long-attack/ This attack revives the controversy about LORAN-C shutdown. Has anyody any recent info on the LORAN tests of last spring? Is LORAN back on the air, even in a minimal system. Best, -John ___ time-nuts mailing 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] Shera PIC Firmware file
Hi Bill: I don't see the address for Shera's web page! Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of WB6BNQ Sent: Monday, August 27, 2012 3:16 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Shera PIC Firmware file Ron, Here is Mr. Shera's actual web page on the topic. At the bottom you will find the HEX file file for the firmware. Don't ask as there is no published assembly listing of the firmware. Mr. Shera does not feel like releasing it to the general public at this time. Also, on that page is a link to the original article he wrote on the project. So it is a good page to bookmark. BillWB6BNQ Ron Ward wrote: Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing 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] Datum 1000B's any hints ?
Wondering if anyone has any practical suggestions as to the operation of stand alone Datum 1000B's.Over the last 6 months or so I've acquired 3 of them and I haven't been that impressed with their performance. I've got a nicely running FTS 1050 and an 8600 series bva along with time lab and some HP5370's so I'm reasonably confident in my references and test setup. I've been powering them from stand alone linear power supplies with separate supply and return leads for the oven and electronics and have left them alone for several weeks at a time. I haven't touched the efc input yet and am wondering if leaving that floating could be causing issues. I also tried running one of them from my stand alone 24 volt battery system which didn't seem to help. They all seem to be gradually getting better over time but I'm thinking either I have three duds or there is something basic I'm missing (ie. perhaps I need to connect the efc input ?). I'm also wondering what if anything to connect the case ground to. The most promising of the bunch from an adev perspective is also off frequency by approx a hz or so but seems to be slowly drifting towards the correct value. Any comments would be appreciated. Regards Mark Spencer. Sent from my iPad ___ time-nuts mailing 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] Datum 1000B's any hints ?
without any EFC I would expect it to be 1 Hz low. If less than 5 Volt will get it on frequency I would use a 78L12 from your main supply followed by a TI REF02. Worked for me. Bert Kehren In a message dated 8/27/2012 10:13:35 P.M. Eastern Daylight Time, mspencer12...@yahoo.ca writes: Wondering if anyone has any practical suggestions as to the operation of stand alone Datum 1000B's.Over the last 6 months or so I've acquired 3 of them and I haven't been that impressed with their performance. I've got a nicely running FTS 1050 and an 8600 series bva along with time lab and some HP5370's so I'm reasonably confident in my references and test setup. I've been powering them from stand alone linear power supplies with separate supply and return leads for the oven and electronics and have left them alone for several weeks at a time. I haven't touched the efc input yet and am wondering if leaving that floating could be causing issues. I also tried running one of them from my stand alone 24 volt battery system which didn't seem to help. They all seem to be gradually getting better over time but I'm thinking either I have three duds or there is something basic I'm missing (ie. perhaps I need to connect the efc input ?). I'm also wondering what if anything to connect the case ground to. The most promising of the bunch from an adev perspective is also off frequency by approx a hz or so but seems to be slowly drifting towards the correct value. Any comments would be appreciated. Regards Mark Spencer. Sent from my iPad ___ time-nuts mailing 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] oscillators
On 8/27/12 4:15 PM, Rick Karlquist wrote: Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. The goal wasn't to turn a quartz oscillator into an atomic clock replacement, but simply to get the oscillator through a 1 hour or so holdover time during GPS outages. It sort of worked for that very limited purpose, but in general, past performance of HP crystals wasn't a very good predictor of future results. Crystals would age in one direction for a while and possibly slow down as time when on, but then then might start aging in the other direction. There were also frequency jumps that were substantial and totally random. The reason why the HP crystals were unpredictable was that all the deterministic processes such as mass preferentially depositing on the crystal, so as to make the frequency age lower, had been eliminated by years of manufacturing improvements. The remaining processes were of the nature of quartz stress relaxation that were very random. Rick Karlquist We see similar things in USOs (and other components as well) for spaceflight.. Things that people worried about 60 or more years ago just don't occur anymore. People used to obsessively try to match diodes in HV strings, for instance, because the process variability was high enough to make a difference. These days, you get a reel of diodes and they're all pretty much the same, and even reel to reel from month to month they don't change much.That's what all that 6-sigma stuff is all about, after all. All the low hanging, and even middle hanging, fruit has been picked.. (one big exception.. ICs which are not designed for radiation tolerance seem to have large variability in radiation tolerance..it's just not something that's controlled for in the process) ___ time-nuts mailing 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] Shera PIC Firmware file
Hi Ron, My apologies, I got to typing and forgot to append the URL line; which is: http://www.rt66.com/~shera/index_fs.htm Sorry about that ! If you haven't already it is worth reading the original QST article which he has a link to at the bottom of the page. BillWB6BNQ Ron Ward wrote: Hi Bill: I don't see the address for Shera's web page! Thanks, Ron -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of WB6BNQ Sent: Monday, August 27, 2012 3:16 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Shera PIC Firmware file Ron, Here is Mr. Shera's actual web page on the topic. At the bottom you will find the HEX file file for the firmware. Don't ask as there is no published assembly listing of the firmware. Mr. Shera does not feel like releasing it to the general public at this time. Also, on that page is a link to the original article he wrote on the project. So it is a good page to bookmark. BillWB6BNQ Ron Ward wrote: Hi again all: Does anyone know where I can get a copy of Shera's PIC firmware for his GPS-Based Frequency Standard? Also, what enhancements are available for the latest firmware? Thanks again, Ron ___ time-nuts mailing 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] Lucent RTGm-II-XO Slow Acquisition
Hi Jerry ; I assume you mean RFTGm-II-XO. The cell sites usually had an Andrew 26dB antenna with a real short coax run. They also had a 40dB antenna option if needed. Unless you have a long coax run the Symmetricom ant should be ideal. I don't think the RFTGm-II-XO lock as quickly the Thundebolt but yours sounds like something is not right. Does the software allow you to set mask angle and PDOP? It could be set to high and be ignoring Sats. It also could possibly be set for a past fixed location. I have a few RFTGm-II-XO/RFTGm-II-RB combos but have never played with the software. Where did you find your software? And do you have a manual? Thanks; Thomas Knox From: jster...@att.net To: time-nuts@febo.com Date: Tue, 28 Aug 2012 00:28:27 -0400 Subject: [time-nuts] Lucent RTGm-II-XO Slow Acquisition I have a RTGm-II-XO and it takes quite some time to acquire the minimum 4 satellites. Using the same Symmetricom antenna with my Thunderbolt, it acquires 6-8 satellites in 15-20 mins while the RTGm-II-XO takes 60 minutes and sometimes much longer where I have power cycled it to get it out of warm-up. On power-up, the red alarm goes off within 15mins as programmed. I have preset my GPS coordinates using the RS-422 interface and Lucent software and set the coax length as well. The antenna voltage is correct at 4.9vdc and the antenna is drawing about 25 ma. The Lucent software shows correct XO voltages per the manual. Any advice appreciated. jerry ___ time-nuts mailing 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] oscillators
On Mon, Aug 27, 2012 at 7:33 PM, Jim Lux jim...@earthlink.net wrote: On 8/27/12 4:15 PM, Rick Karlquist wrote: Several decades ago, the concept of the smart clock arose at what was then HP. The idea was as discussed here to characterize past aging, predict future aging, and then correct the aging. We know what a OCXO is and a TCXO is. I was at a presentation at work a whike back and they called what you describe a MPCXO or MicroProcessor Compensated XO.They said the characteristics were between the OCXO and TCXO Doesn't the thunderbolt do this. I think it watches the aging rate of the OCXO and adjusts during hold over. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
