Re: [time-nuts] Thunderbolt question
Thanks everyone. This has given me a lot of things to check as I further investigate over the next few evenings. I'll let you know what I find. Chris > On Aug 5, 2017, at 3:07 PM, Charles Steinmetz wrote: > > Arthur wrote: > >> I’d say it would be an MMIC amp similar to this device [Avago MGA-87563] > > If a chip similar to the Avago part Arthur referenced is what is installed, > which seems plausible, the 0.749v on the RF input (Pin 3) is a fault and is > caused by an external source of voltage (3.417v) imposed on the RF output > (Pin 6) through the internal feedback resistor to Pin 3, attenuated by the > gate resistor. > > Avago says this particular chip needs to have 0vDC at Pins 3 and 6, so if the > connected parts would impose any DC voltage on those pins, external blocking > capacitors must be used on Pins 3 and 6. You might check to see if there are > blocking caps (at least at Pin 6), and if they are good. (Alternatively, the > internal output capacitor from Pin 6 back to the output FET source may be > bad.) > > Of course, don't expect a bad external cap to be the only other problem -- if > it is bad, the 6-pin amp may well be bad, as well as whatever is connected to > the other side of the cap. > > 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. ___ time-nuts mailing 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 question
Arthur wrote: I’d say it would be an MMIC amp similar to this device [Avago MGA-87563] If a chip similar to the Avago part Arthur referenced is what is installed, which seems plausible, the 0.749v on the RF input (Pin 3) is a fault and is caused by an external source of voltage (3.417v) imposed on the RF output (Pin 6) through the internal feedback resistor to Pin 3, attenuated by the gate resistor. Avago says this particular chip needs to have 0vDC at Pins 3 and 6, so if the connected parts would impose any DC voltage on those pins, external blocking capacitors must be used on Pins 3 and 6. You might check to see if there are blocking caps (at least at Pin 6), and if they are good. (Alternatively, the internal output capacitor from Pin 6 back to the output FET source may be bad.) Of course, don't expect a bad external cap to be the only other problem -- if it is bad, the 6-pin amp may well be bad, as well as whatever is connected to the other side of the cap. 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] Thunderbolt question
On Sat, 5 Aug 2017 10:47:40 -0400 paul swed wrote: > The .5 on the f connector is an issue and thats through the filter on top > of the board made of traces and 3 caps. From Arthur's digging I would agree > he found the chip or one that would work. But that chips voltages seem to > match so most likely not the issue. What does the F connector measure to > ground? A strike could have burned the internals of the F connector. Above > the DC filer will be some form of current limiting. Maybe an inductor or > resistor. Not necessarily. You need quite a bit of energy to leave visible burn marks on a connector. It's more likely that the spike at the input just reached a couple 100V. Too little to damage the connector, but enough to fry a few components and make them go *pop*. Attila Kinali -- You know, the very powerful and the very stupid have one thing in common. They don't alters their views to fit the facts, they alter the facts to fit the views, which can be uncomfortable if you happen to be one of the facts that needs altering. -- The Doctor ___ time-nuts mailing 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 question
The .5 on the f connector is an issue and thats through the filter on top of the board made of traces and 3 caps. From Arthur's digging I would agree he found the chip or one that would work. But that chips voltages seem to match so most likely not the issue. What does the F connector measure to ground? A strike could have burned the internals of the F connector. Above the DC filer will be some form of current limiting. Maybe an inductor or resistor. On Sat, Aug 5, 2017 at 12:00 AM, Chris Waldrup wrote: > Hi, > > I've changed the blown MMBT3904 in the antenna sense circuit and I still > have no 5V to the antenna. I measure 0.5V DC on the F connector. > There are two Murata filters (F2 and F3) on the RF path to the antenna. In > between the two silver colored filters is a 6 lead SOT package marked 51A. > The PCB silkscreen says Q13. > I have measured the following voltages on this part: > Pin 1= 0v > Pin 2= 0v > Pin 3= 0.749V > Pin 4= 4.892v > Pin 5= 0v > Pin 6= 3.417v > > The trace from pin 3 of this part goes to the F2 filter and the output of > F2 goes to the F connector. I'm getting 0.5V on the output of this filter. > I'm suspecting this Q13 part may be bad but I'm not sure what the part is. > Searching the net for 51A marking came up with a large 2 pin shottky which > this isn't. > > Chris > KD4PBJ > > > On Aug 4, 2017, at 5:27 PM, Chris Waldrup wrote: > > > > Thanks guys. > > I've opened up my T bolt and noticed a SOT23 packaged part has the top > blown off. > > The PPS BNC jack has U19 beside it. > > The next part is blown. Could someone take a closeup of the five parts > around U19? > > The intact parts are marked: > > 5Dz > > 1AM > > and two 2Az parts. > > > > > > Chris > > > >> On Aug 4, 2017, at 4:13 PM, Arthur Dent > wrote: > >> > >> Actually that isn't my photo I linked to but one I just Googled. That is > >> probably a board revision most people don't have but it was the first > one > >> I saw so I used it just to show that the GPS receiver is part of the > >> only circuit board and not another easily replaceable board like in some > >> other units. > >> > >> I just took a couple of photos of the later revision of the board for > >> anyone interested in seeing what might be fried. In the photo of the > >> top of the board the signal comes into a filter then to a 25db amp > >> marked AM50002 by Macom. Above the filter near the input is where the > >> decoupled +5VDC for the antenna is connected. If you are only reading > >> 0.5VDC, if your're lucky it might only be the amp is fried and that > >> could be an easy fix. If the 5VDC is ok with the amp input pin lifted, > >> it might be the only problem. I wouldn't bet on it though. The 4031 I > >> believe is a 1575.42 SAW filter > >> > >> The photo of the bottom of the receiver area shows a Sawtek filter and > >> other parts. At the bottom of the photo is C460, a feedthrough capacitor > >> and that might be where the receiver output is but where my Tbolts are > >> working I don't feel the need to look into whether you could connect > >> the output of a seperate GPS receiver there to make it work. > >> > >> I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz > >> connections to SMA connectors on the back so I can test other > oscillators > >> or GPSDOs that don't have an easy way to monitor of graph the stability > >> of those units and using Lady Heather gives me a good way to compare the > >> graphs to ones I'm used to. You might possibly be able to replace the > >> built-in receiver but it might be easier to buy a working Thunderbolt. > >> > >> > >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS% > 20top%201_zpslgxunnyw.jpg > >> > >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS% > 20bottom%201_zpschvruppt.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. > ___ time-nuts mailing 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] Thunderbolt question
Pin 1= 0v Pin 2= 0v Pin 3= 0.749V Pin 4= 4.892v Pin 5= 0v Pin 6= 3.417v I’d say it would be an MMIC amp similar to this device. It has the same pin-out so it is a possibility. The Amp In my newer version is an 23 db gain device but 8-pin so I Suspect your version may have similar specs. Here is a Datasheet on the MGA-87563 6-pin device. http://www.efo.ru/components/avago/catalog/files/pdf/AV01_0200EN.PDF ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt question
Hi, I've changed the blown MMBT3904 in the antenna sense circuit and I still have no 5V to the antenna. I measure 0.5V DC on the F connector. There are two Murata filters (F2 and F3) on the RF path to the antenna. In between the two silver colored filters is a 6 lead SOT package marked 51A. The PCB silkscreen says Q13. I have measured the following voltages on this part: Pin 1= 0v Pin 2= 0v Pin 3= 0.749V Pin 4= 4.892v Pin 5= 0v Pin 6= 3.417v The trace from pin 3 of this part goes to the F2 filter and the output of F2 goes to the F connector. I'm getting 0.5V on the output of this filter. I'm suspecting this Q13 part may be bad but I'm not sure what the part is. Searching the net for 51A marking came up with a large 2 pin shottky which this isn't. Chris KD4PBJ > On Aug 4, 2017, at 5:27 PM, Chris Waldrup wrote: > > Thanks guys. > I've opened up my T bolt and noticed a SOT23 packaged part has the top blown > off. > The PPS BNC jack has U19 beside it. > The next part is blown. Could someone take a closeup of the five parts around > U19? > The intact parts are marked: > 5Dz > 1AM > and two 2Az parts. > > > Chris > >> On Aug 4, 2017, at 4:13 PM, Arthur Dent wrote: >> >> Actually that isn't my photo I linked to but one I just Googled. That is >> probably a board revision most people don't have but it was the first one >> I saw so I used it just to show that the GPS receiver is part of the >> only circuit board and not another easily replaceable board like in some >> other units. >> >> I just took a couple of photos of the later revision of the board for >> anyone interested in seeing what might be fried. In the photo of the >> top of the board the signal comes into a filter then to a 25db amp >> marked AM50002 by Macom. Above the filter near the input is where the >> decoupled +5VDC for the antenna is connected. If you are only reading >> 0.5VDC, if your're lucky it might only be the amp is fried and that >> could be an easy fix. If the 5VDC is ok with the amp input pin lifted, >> it might be the only problem. I wouldn't bet on it though. The 4031 I >> believe is a 1575.42 SAW filter >> >> The photo of the bottom of the receiver area shows a Sawtek filter and >> other parts. At the bottom of the photo is C460, a feedthrough capacitor >> and that might be where the receiver output is but where my Tbolts are >> working I don't feel the need to look into whether you could connect >> the output of a seperate GPS receiver there to make it work. >> >> I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz >> connections to SMA connectors on the back so I can test other oscillators >> or GPSDOs that don't have an easy way to monitor of graph the stability >> of those units and using Lady Heather gives me a good way to compare the >> graphs to ones I'm used to. You might possibly be able to replace the >> built-in receiver but it might be easier to buy a working Thunderbolt. >> >> >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20top%201_zpslgxunnyw.jpg >> >> http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20bottom%201_zpschvruppt.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] Thunderbolt question
Thanks guys. I've opened up my T bolt and noticed a SOT23 packaged part has the top blown off. The PPS BNC jack has U19 beside it. The next part is blown. Could someone take a closeup of the five parts around U19? The intact parts are marked: 5Dz 1AM and two 2Az parts. Chris > On Aug 4, 2017, at 4:13 PM, Arthur Dent wrote: > > Actually that isn't my photo I linked to but one I just Googled. That is > probably a board revision most people don't have but it was the first one > I saw so I used it just to show that the GPS receiver is part of the > only circuit board and not another easily replaceable board like in some > other units. > > I just took a couple of photos of the later revision of the board for > anyone interested in seeing what might be fried. In the photo of the > top of the board the signal comes into a filter then to a 25db amp > marked AM50002 by Macom. Above the filter near the input is where the > decoupled +5VDC for the antenna is connected. If you are only reading > 0.5VDC, if your're lucky it might only be the amp is fried and that > could be an easy fix. If the 5VDC is ok with the amp input pin lifted, > it might be the only problem. I wouldn't bet on it though. The 4031 I > believe is a 1575.42 SAW filter > > The photo of the bottom of the receiver area shows a Sawtek filter and > other parts. At the bottom of the photo is C460, a feedthrough capacitor > and that might be where the receiver output is but where my Tbolts are > working I don't feel the need to look into whether you could connect > the output of a seperate GPS receiver there to make it work. > > I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz > connections to SMA connectors on the back so I can test other oscillators > or GPSDOs that don't have an easy way to monitor of graph the stability > of those units and using Lady Heather gives me a good way to compare the > graphs to ones I'm used to. You might possibly be able to replace the > built-in receiver but it might be easier to buy a working Thunderbolt. > > > http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20top%201_zpslgxunnyw.jpg > > http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20bottom%201_zpschvruppt.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] Thunderbolt question
Looked at the pix and yes the ant power are the caps and traces on the left. Hard to get lightning through most saw filters. There is an inductor to the right of the am50002 preamp and that would also be a great check. Open shorted the V should be 1-3V approx. 0 or 5 is bad. I looked to see if am50002 were available a quick search didn't show anything. Regards Paul WB8TSL On Fri, Aug 4, 2017 at 5:13 PM, Arthur Dent wrote: > Actually that isn't my photo I linked to but one I just Googled. That is > probably a board revision most people don't have but it was the first one > I saw so I used it just to show that the GPS receiver is part of the > only circuit board and not another easily replaceable board like in some > other units. > > I just took a couple of photos of the later revision of the board for > anyone interested in seeing what might be fried. In the photo of the > top of the board the signal comes into a filter then to a 25db amp > marked AM50002 by Macom. Above the filter near the input is where the > decoupled +5VDC for the antenna is connected. If you are only reading > 0.5VDC, if your're lucky it might only be the amp is fried and that > could be an easy fix. If the 5VDC is ok with the amp input pin lifted, > it might be the only problem. I wouldn't bet on it though. The 4031 I > believe is a 1575.42 SAW filter > > The photo of the bottom of the receiver area shows a Sawtek filter and > other parts. At the bottom of the photo is C460, a feedthrough capacitor > and that might be where the receiver output is but where my Tbolts are > working I don't feel the need to look into whether you could connect > the output of a seperate GPS receiver there to make it work. > > I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz > connections to SMA connectors on the back so I can test other oscillators > or GPSDOs that don't have an easy way to monitor of graph the stability > of those units and using Lady Heather gives me a good way to compare the > graphs to ones I'm used to. You might possibly be able to replace the > built-in receiver but it might be easier to buy a working Thunderbolt. > > > http://i906.photobucket.com/albums/ac262/rjb1998/GPS% > 20top%201_zpslgxunnyw.jpg > > http://i906.photobucket.com/albums/ac262/rjb1998/GPS% > 20bottom%201_zpschvruppt.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.
[time-nuts] Thunderbolt question
Actually that isn't my photo I linked to but one I just Googled. That is probably a board revision most people don't have but it was the first one I saw so I used it just to show that the GPS receiver is part of the only circuit board and not another easily replaceable board like in some other units. I just took a couple of photos of the later revision of the board for anyone interested in seeing what might be fried. In the photo of the top of the board the signal comes into a filter then to a 25db amp marked AM50002 by Macom. Above the filter near the input is where the decoupled +5VDC for the antenna is connected. If you are only reading 0.5VDC, if your're lucky it might only be the amp is fried and that could be an easy fix. If the 5VDC is ok with the amp input pin lifted, it might be the only problem. I wouldn't bet on it though. The 4031 I believe is a 1575.42 SAW filter The photo of the bottom of the receiver area shows a Sawtek filter and other parts. At the bottom of the photo is C460, a feedthrough capacitor and that might be where the receiver output is but where my Tbolts are working I don't feel the need to look into whether you could connect the output of a seperate GPS receiver there to make it work. I do have one Tbolt that has no oscillator. I brought the EFC and 10Mhz connections to SMA connectors on the back so I can test other oscillators or GPSDOs that don't have an easy way to monitor of graph the stability of those units and using Lady Heather gives me a good way to compare the graphs to ones I'm used to. You might possibly be able to replace the built-in receiver but it might be easier to buy a working Thunderbolt. http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20top%201_zpslgxunnyw.jpg http://i906.photobucket.com/albums/ac262/rjb1998/GPS%20bottom%201_zpschvruppt.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] Thunderbolt question
Hi > On Aug 4, 2017, at 9:45 AM, paul swed wrote: > > Arthur > Thanks for the picture. I have a TBolt also and its working just fine at > the moment. > But one day it may not. As several people have mentioned lightnings an > issue. > > So going down the crazy thought path for a moment. > It appears from your pix you can figure out what the GPS receiver chip set > is. > The thought would be understand the chip set. > Locate the TX RX and 1pps and plug another receiver in. > Yes its a kluge and maybe a separate board level GPS receiver can not be > found... > But at least an approach. On the TBolt … much more complex. The device looks at code phase to discipline the OCXO. The “guts” of the TBolt need to work closely with the receiver. If you really want to resurrect a dead one, it’s probably best to trace out the RF section and start replacing this and that. This of course *assumes* it’s not blown someplace like the RS-232 end of things … Most of the RF front end bits appear to be fairly generic. With care, you should be able to swap them out. Bob > > One other comment. If it is lightning then just maybe its the preamp chip. > They are typically 3 pin soics and replaceable. > Regards > Paul > WB8TSL > > On Fri, Aug 4, 2017 at 9:34 AM, Arthur Dent > wrote: > >> The Thunderbolt is a single board with the GPS receiver in the lower right >> between the oscillator case and the connectors in the photo in this link. >> >> https://www.eevblog.com/forum/testgear/trimble-thunderbolt- >> gps-disciplined-oscillator/?action=dlattach;attach=102948;image >> ___ >> time-nuts mailing 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] Thunderbolt question
Arthur Thanks for the picture. I have a TBolt also and its working just fine at the moment. But one day it may not. As several people have mentioned lightnings an issue. So going down the crazy thought path for a moment. It appears from your pix you can figure out what the GPS receiver chip set is. The thought would be understand the chip set. Locate the TX RX and 1pps and plug another receiver in. Yes its a kluge and maybe a separate board level GPS receiver can not be found... But at least an approach. One other comment. If it is lightning then just maybe its the preamp chip. They are typically 3 pin soics and replaceable. Regards Paul WB8TSL On Fri, Aug 4, 2017 at 9:34 AM, Arthur Dent wrote: > The Thunderbolt is a single board with the GPS receiver in the lower right > between the oscillator case and the connectors in the photo in this link. > > https://www.eevblog.com/forum/testgear/trimble-thunderbolt- > gps-disciplined-oscillator/?action=dlattach;attach=102948;image > ___ > time-nuts mailing 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] Thunderbolt question
The Thunderbolt is a single board with the GPS receiver in the lower right between the oscillator case and the connectors in the photo in this link. https://www.eevblog.com/forum/testgear/trimble-thunderbolt-gps-disciplined-oscillator/?action=dlattach;attach=102948;image ___ time-nuts mailing 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 question
At 12:13 AM 8/4/2017, Chris Waldrup wrote: So no voltage out to antenna. I do have one of those 6V max polyphasers but we did get some really close strikes recently. Oh. As someone who lost a tbolt to lightning last year, I feel your pain. I've had to change the Oncore UT Plus receiver board once in my Datum Starloc II and it was easy. Hope this is a similar Motorola Oncore. I'll open it up tomorrow and see. I need to find a better source of the There's no replaceable GPS module as such in the tbolt. -- newell N5TNL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt question
Couldn't wait till morning on this as it was on my mind this evening. I unplugged the Thunderbolt from the wall and plugged it back in. Immediately the frequency counter attached went from 9.. to zero then when it was powered back up went to the other side of 10 MHz at 10.000 and "Disciplining" came up on the control program. I measured the voltage on the coax and it was 0.5V. So no voltage out to antenna. I do have one of those 6V max polyphasers but we did get some really close strikes recently. I've had to change the Oncore UT Plus receiver board once in my Datum Starloc II and it was easy. Hope this is a similar Motorola Oncore. I'll open it up tomorrow and see. I need to find a better source of the Oncore UT Plus modules rather than waiting for the Chinese slow boat. Chris > On Aug 3, 2017, at 10:21 PM, Chris Waldrup wrote: > > Thank you Didier. > I'll check tomorrow for further issues. > > Chris > >> On Aug 3, 2017, at 10:05 PM, Didier Juges wrote: >> >> "If the Thunderbolt loses satellites, does it still put out a 10 Mhz >> signal?" >> >> Yes of course. When that happens, the Thunderbolt is said to be in holdover. >> >>> On Aug 3, 2017 9:29 PM, "Chris Waldrup" wrote: >>> >>> Hi, >>> >>> I just noticed the laptop that is always connected to my Thunderbolt had a >>> yellow block under COM1 on the Tboltmon program where it normally is green. >>> Also the date up on the screen was in early July. Satellites were still >>> shown. >>> The counter I leave connected still shows a 10 Mhz output. >>> I reset the program and this time all fields are ??? and com not detected. >>> I had thought maybe the laptop hung up. >>> I'll look at my system tomorrow. I'm trying to do a divide and conquer. If >>> the Thunderbolt loses satellites, does it still put out a 10 Mhz signal? >>> >>> Thank you. >>> >>> Chris >>> KD4PBJ >>> ___ >>> time-nuts mailing 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] Thunderbolt question
Thank you Didier. I'll check tomorrow for further issues. Chris > On Aug 3, 2017, at 10:05 PM, Didier Juges wrote: > > "If the Thunderbolt loses satellites, does it still put out a 10 Mhz > signal?" > > Yes of course. When that happens, the Thunderbolt is said to be in holdover. > >> On Aug 3, 2017 9:29 PM, "Chris Waldrup" wrote: >> >> Hi, >> >> I just noticed the laptop that is always connected to my Thunderbolt had a >> yellow block under COM1 on the Tboltmon program where it normally is green. >> Also the date up on the screen was in early July. Satellites were still >> shown. >> The counter I leave connected still shows a 10 Mhz output. >> I reset the program and this time all fields are ??? and com not detected. >> I had thought maybe the laptop hung up. >> I'll look at my system tomorrow. I'm trying to do a divide and conquer. If >> the Thunderbolt loses satellites, does it still put out a 10 Mhz signal? >> >> Thank you. >> >> Chris >> KD4PBJ >> ___ >> time-nuts mailing 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] Thunderbolt question
"If the Thunderbolt loses satellites, does it still put out a 10 Mhz signal?" Yes of course. When that happens, the Thunderbolt is said to be in holdover. On Aug 3, 2017 9:29 PM, "Chris Waldrup" wrote: > Hi, > > I just noticed the laptop that is always connected to my Thunderbolt had a > yellow block under COM1 on the Tboltmon program where it normally is green. > Also the date up on the screen was in early July. Satellites were still > shown. > The counter I leave connected still shows a 10 Mhz output. > I reset the program and this time all fields are ??? and com not detected. > I had thought maybe the laptop hung up. > I'll look at my system tomorrow. I'm trying to do a divide and conquer. If > the Thunderbolt loses satellites, does it still put out a 10 Mhz signal? > > Thank you. > > Chris > KD4PBJ > ___ > time-nuts mailing 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] Thunderbolt question
Hi, I just noticed the laptop that is always connected to my Thunderbolt had a yellow block under COM1 on the Tboltmon program where it normally is green. Also the date up on the screen was in early July. Satellites were still shown. The counter I leave connected still shows a 10 Mhz output. I reset the program and this time all fields are ??? and com not detected. I had thought maybe the laptop hung up. I'll look at my system tomorrow. I'm trying to do a divide and conquer. If the Thunderbolt loses satellites, does it still put out a 10 Mhz signal? Thank you. Chris KD4PBJ ___ time-nuts mailing 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 Question
wa6...@comcast.net said: > I have been using a surplus Thunderbolt for about six months, and it seemed to > be working fine. In January 2012, a message came up in yellow, (LEAP > PENDING!), I don't know what this means, but since it didn't go away on Feb > 28, > must not be leap year related. About a week ago I got a Holdover: xx secs, > message. It was a new figure in yellow. Yesterday the Thunderbolt stopped > working correctly, there were no satellites found. I tried Lady Heather, and > Trimble Studio without success.I finally got the unit back in service with > a program called "Tboltmon.exe". After it was running for a couple of hours I > restarted Lady Heather. This morning I again have "Holdover: 50 secs". > Does it sound normal, or is this unit headed for the junk box? I didn't see anything that you said that sounds unreasonable. There is a leap second scheduled for the end of June 2012. That info gets distributed via GPS. The TBolt will pass it on to client software. I don't remember the details, but you can find them if you look in the TBolt software data sheet. There is a quirk with NTP. It also has a mechanism for distributing leap-pending info. The catch is that it assumes the leap will be at the end of the current month. (I hacked a Jun/Dec filter into the HP/Z3801A driver because it screwed up the last time we had a leap second. That seemed easier to test and less likely to be buggy than trying to decode the actual time of the next leap second.) I should go check the TBolt code. On the holdover... Holdover just means that you can't see any good-enough satellites. (You only need one for timekeeping.) How good is your antenna location? Were you watching to see if it was going into holdover before? My antenna setup is poor. My TBolt goes into holdover several times a day, more on a bad day, maybe none on a good day. That's great for testing software, not so good for providing a super-clean time or frequency reference. How many times and/or how long it stays in holdover depends upon ??? (I don't know.) It may depend on the phasing of the GPS satellites. It may depend on the weather and/or the amount of water in/on my roof and/or the local trees. (I have a big pine tree to the south/southeast.) -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Question
Not yet Marcus- that sort of technology will come right after the ftl drive, but just before we start building a dyson sphere.. On Tue, Apr 24, 2012 at 7:00 AM, Magnus Danielson wrote: > > > I thought someone finally put a cesium on the step motor keeping the ear > rotation. But no, free-wheeling like always. There is no order in this > universe. > > Cheers, > Magnus Ken. ___ time-nuts mailing 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 Question
On 04/23/2012 07:01 PM, Tom Van Baak wrote: I have been using a surplus Thunderbolt for about six months, and it seemed to be working fine. In January 2012, a message came up in yellow, (LEAP PENDING!), I don't know what this means, but since it didn't go away on Feb 28, must not be leap year related. Hi Ed, Right, in this case the "LEAP" refers to a leap second, not a leap year. When the next leap second occurs this summer, the yellow warning will go away. As you know, leap years are used to keep "days" and "years" in sync, where a day is earth rotation (about its axis) and a year is earth revolution (around the sun). Last one was: Feb 29, 2012. Similarly, leap seconds are used to keep "seconds" and "days" in sync, where a second is now defined by atomic standards and a day is earth rotation. Next one is: 19:59:60 EDT, Jun 30, 2012. Keeping clocks in sync is a significant part of the timekeeping world. For example, with quartz and GPS it's easy to "discipline" quartz in order to steer it closer to GPS. This is done by making slight changes in quartz EFC voltage to change the frequency, to close the differential time error. But when it comes to orbits and planets, objects too large for us to change their rate, objects which have no EFC input, we have to resort to making artificial, bookkeeping, virtual steps in time instead of gradual changes in physical rate. I thought someone finally put a cesium on the step motor keeping the ear rotation. But no, free-wheeling like always. There is no order in this universe. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Question
Ed, the message about leap pending refers to an impending leap second, in June I think but others may know more... It will happen and the message will go away. From your LH screen, I would say that your signal levels are way too low. I don't know why, perhaps low antenna gain, a badly sited antenna, even indoors maybe? I suspect the t'bolt is working as it should. You don't show your signal strength numbers, but here in Southern California with a well sited -hp- antenna, I see all visible sats with between 47 and 50 signal strength numbers and thus large circles on the map display. Dan ___ time-nuts mailing 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 Question
I have been using a surplus Thunderbolt for about six months, and it seemed to be working fine. In January 2012, a message came up in yellow, (LEAP PENDING!), I don't know what this means, but since it didn't go away on Feb 28, must not be leap year related. Hi Ed, Right, in this case the "LEAP" refers to a leap second, not a leap year. When the next leap second occurs this summer, the yellow warning will go away. As you know, leap years are used to keep "days" and "years" in sync, where a day is earth rotation (about its axis) and a year is earth revolution (around the sun). Last one was: Feb 29, 2012. Similarly, leap seconds are used to keep "seconds" and "days" in sync, where a second is now defined by atomic standards and a day is earth rotation. Next one is: 19:59:60 EDT, Jun 30, 2012. Keeping clocks in sync is a significant part of the timekeeping world. For example, with quartz and GPS it's easy to "discipline" quartz in order to steer it closer to GPS. This is done by making slight changes in quartz EFC voltage to change the frequency, to close the differential time error. But when it comes to orbits and planets, objects too large for us to change their rate, objects which have no EFC input, we have to resort to making artificial, bookkeeping, virtual steps in time instead of gradual changes in physical rate. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Question
There is a leap second waiting for June/July this year. On Mon, Apr 23, 2012 at 6:16 PM, Chris Albertson wrote: > Maybe it's the antenna, or a short in the cable (water in the coax) or a > nearby transmitters that is jamming the GPS signal. The simplest way to > diagnose the problem is by swapping parts.Is your antenna in a good > location with a direct view of the entire sky? > > > > > On Mon, Apr 23, 2012 at 9:05 AM, Ed Mersich wrote: > > > I have been using a surplus Thunderbolt for about six months, and it > seemed > > to be working fine. In January 2012, a message came up in yellow, (LEAP > > PENDING!), I don't know what this means, but since it didn't go away on > Feb > > 28, must not be leap year related. About a week ago I got a Holdover: xx > > secs, message. It was a new figure in yellow. Yesterday the Thunderbolt > > stopped working correctly, there were no satellites found. I tried Lady > > Heather, and Trimble Studio without success.I finally got the unit > back > > in service with a program called "Tboltmon.exe". After it was running > for > > a > > couple of hours I restarted Lady Heather. This morning I again have > > "Holdover: 50 secs". > > > > > > > > Does it sound normal, or is this unit headed for the junk box? Sorry, I > am > > not very technical about this type of electronics. You can see a > snapshot > > of Lady Heather at: http://wa6rzw.homelinux.net/addon/fmt/fmt_2.php Any > > comments or suggestions would be appreciated. 73 Ed, WA6RZW > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > -- > > Chris Albertson > Redondo Beach, California > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Thunderbolt Question
Maybe it's the antenna, or a short in the cable (water in the coax) or a nearby transmitters that is jamming the GPS signal. The simplest way to diagnose the problem is by swapping parts.Is your antenna in a good location with a direct view of the entire sky? On Mon, Apr 23, 2012 at 9:05 AM, Ed Mersich wrote: > I have been using a surplus Thunderbolt for about six months, and it seemed > to be working fine. In January 2012, a message came up in yellow, (LEAP > PENDING!), I don't know what this means, but since it didn't go away on Feb > 28, must not be leap year related. About a week ago I got a Holdover: xx > secs, message. It was a new figure in yellow. Yesterday the Thunderbolt > stopped working correctly, there were no satellites found. I tried Lady > Heather, and Trimble Studio without success.I finally got the unit back > in service with a program called "Tboltmon.exe". After it was running for > a > couple of hours I restarted Lady Heather. This morning I again have > "Holdover: 50 secs". > > > > Does it sound normal, or is this unit headed for the junk box? Sorry, I am > not very technical about this type of electronics. You can see a snapshot > of Lady Heather at: http://wa6rzw.homelinux.net/addon/fmt/fmt_2.php Any > comments or suggestions would be appreciated. 73 Ed, WA6RZW > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Thunderbolt Question
I have been using a surplus Thunderbolt for about six months, and it seemed to be working fine. In January 2012, a message came up in yellow, (LEAP PENDING!), I don't know what this means, but since it didn't go away on Feb 28, must not be leap year related. About a week ago I got a Holdover: xx secs, message. It was a new figure in yellow. Yesterday the Thunderbolt stopped working correctly, there were no satellites found. I tried Lady Heather, and Trimble Studio without success.I finally got the unit back in service with a program called "Tboltmon.exe". After it was running for a couple of hours I restarted Lady Heather. This morning I again have "Holdover: 50 secs". Does it sound normal, or is this unit headed for the junk box? Sorry, I am not very technical about this type of electronics. You can see a snapshot of Lady Heather at: http://wa6rzw.homelinux.net/addon/fmt/fmt_2.php Any comments or suggestions would be appreciated. 73 Ed, WA6RZW ___ time-nuts mailing 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] Thunderbolt question regarding PPS and 10MHz phase relationship
It can be altered, but only by 50ns. You can invert the phase of the osc sense (feature not available on Thunderbolt-E or Thunderbolts built before March 1998). Use the '^' command in Lady Heather. The PPS output is synchronous with the 10MHz signal and the delay from the preceding zero crossing of the 10Mhz signal to the leading PPS edge cannot be altered. _ Hotmail: Powerful Free email with security by Microsoft. http://clk.atdmt.com/GBL/go/171222986/direct/01/ ___ time-nuts mailing 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 question regarding PPS and 10MHz phase relationship
Bob One way of reducing the effective noise/jitter on the PPS signal when using it with the 5370 to measure the instability of a source with respect to the Thunderbolt is to use the PPS to ARM the 5370 whilst the 10MHz from the thunderbolt starts the 5370 and the source (or a frequency generated by dividing down the source under test) being compared stops the 5370. This reduces the measurement noise by an order of magnitude. Bruce Robert Darlington wrote: > Ah ha! That explains the changing numbers I see on the 5370B (jitter), and > explains why I see no change on the scope other than the jitter. Reading > the manual, I don't see any clear explanation like what you just gave me. I > see my mistake in manual interpretation but not until after reading your > reply. Thank you. > > -Bob > > > > On Sat, Sep 19, 2009 at 5:18 PM, Bruce Griffiths >> wrote: >> > > >> Bob >> >> Robert Darlington wrote: >> >>> Hello all, >>> >>> I'm trying to adjust the time between the leading edge of the PPS square >>> wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The >>> manual seems to indicate the cable delay compensation setting will do >>> >> this. >> >> No, it doesnt. >> This only adjusts the timing of the output PPS signal with respect to >> the GPS time as seen by the receiver. >> It is only intended to compensate for delay in the cable (and >> potentially the active antenna group delay) between the antenna and the >> receiver. >> The PPS output is synchronous with the 10MHz signal and the delay from >> the preceding zero crossing of the 10Mhz signal to the leading PPS edge >> cannot be altered. >> The PPS signal has considerable jitter (~300ps rms ) with respect to the >> 10MHz signal zero crossing. >> >>> As I understand things, this is also called the "PPS Offset" in the >>> >> manual. >> >>> I've changed this from 58ns to -58ns with no visible change over the >>> >> course >> >>> of a 12 hour period on a scope. My test setup is using an old Tek TDS >>> >> 210 >> >>> scope triggering on the PPS on channel 1 through a 50 ohm terminator, >>> trigger set to 400mV and horizontal position adjusted so that 400mV >>> >> crosses >> >>> the center vertical graticule marking. Channel 2 is attached to the >>> >> 10MHz >> >>> signal through another pass-through 50 ohm terminator. What I see on the >>> screen looks like 15ns delay between the triggered PPS signal and the >>> >> zero >> >>> crossing 10MHz signal. My 5370B shows 18ns delay between them when the >>> start input level is set for 400mV. >>> >>> The manual indicates that it could take a while to see a change, but how >>> long is a while? My tbolt has default settings for everything except the >>> PPS Offset value (again, now sitting at -58ns). I expected to at least >>> >> see >> >>> some change over the course of 12 hours or so, but I get nothing. Am I >>> completely misunderstanding something? I accidentally cycled the power >>> after making the settings change after the tbolt was up for a couple of >>> months. I learned to not use a normal serial cable with an APC ups, it >>> >> cut >> >>> the power on the UPS immediately upon plugging it into the back of my PC! >>> Settings were verified after power was brought back up. Total downtime >>> >> was >> >>> perhaps 10 seconds, but that was enough for it to lose almanac data. >>> >>> >>> Thanks, >>> Bob, N3XKB >>> >>> >> Bruce >> >> >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > ___ > time-nuts mailing 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] Thunderbolt question regarding PPS and 10MHz phase relationship
Ah ha! That explains the changing numbers I see on the 5370B (jitter), and explains why I see no change on the scope other than the jitter. Reading the manual, I don't see any clear explanation like what you just gave me. I see my mistake in manual interpretation but not until after reading your reply. Thank you. -Bob On Sat, Sep 19, 2009 at 5:18 PM, Bruce Griffiths wrote: > Bob > > Robert Darlington wrote: > > Hello all, > > > > I'm trying to adjust the time between the leading edge of the PPS square > > wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The > > manual seems to indicate the cable delay compensation setting will do > this. > > > No, it doesnt. > This only adjusts the timing of the output PPS signal with respect to > the GPS time as seen by the receiver. > It is only intended to compensate for delay in the cable (and > potentially the active antenna group delay) between the antenna and the > receiver. > The PPS output is synchronous with the 10MHz signal and the delay from > the preceding zero crossing of the 10Mhz signal to the leading PPS edge > cannot be altered. > The PPS signal has considerable jitter (~300ps rms ) with respect to the > 10MHz signal zero crossing. > > As I understand things, this is also called the "PPS Offset" in the > manual. > > I've changed this from 58ns to -58ns with no visible change over the > course > > of a 12 hour period on a scope. My test setup is using an old Tek TDS > 210 > > scope triggering on the PPS on channel 1 through a 50 ohm terminator, > > trigger set to 400mV and horizontal position adjusted so that 400mV > crosses > > the center vertical graticule marking. Channel 2 is attached to the > 10MHz > > signal through another pass-through 50 ohm terminator. What I see on the > > screen looks like 15ns delay between the triggered PPS signal and the > zero > > crossing 10MHz signal. My 5370B shows 18ns delay between them when the > > start input level is set for 400mV. > > > > The manual indicates that it could take a while to see a change, but how > > long is a while? My tbolt has default settings for everything except the > > PPS Offset value (again, now sitting at -58ns). I expected to at least > see > > some change over the course of 12 hours or so, but I get nothing. Am I > > completely misunderstanding something? I accidentally cycled the power > > after making the settings change after the tbolt was up for a couple of > > months. I learned to not use a normal serial cable with an APC ups, it > cut > > the power on the UPS immediately upon plugging it into the back of my PC! > > Settings were verified after power was brought back up. Total downtime > was > > perhaps 10 seconds, but that was enough for it to lose almanac data. > > > > > > Thanks, > > Bob, N3XKB > > > > Bruce > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing 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 question regarding PPS and 10MHz phase relationship
Bob Robert Darlington wrote: > Hello all, > > I'm trying to adjust the time between the leading edge of the PPS square > wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The > manual seems to indicate the cable delay compensation setting will do this. > No, it doesnt. This only adjusts the timing of the output PPS signal with respect to the GPS time as seen by the receiver. It is only intended to compensate for delay in the cable (and potentially the active antenna group delay) between the antenna and the receiver. The PPS output is synchronous with the 10MHz signal and the delay from the preceding zero crossing of the 10Mhz signal to the leading PPS edge cannot be altered. The PPS signal has considerable jitter (~300ps rms ) with respect to the 10MHz signal zero crossing. > As I understand things, this is also called the "PPS Offset" in the manual. > I've changed this from 58ns to -58ns with no visible change over the course > of a 12 hour period on a scope. My test setup is using an old Tek TDS 210 > scope triggering on the PPS on channel 1 through a 50 ohm terminator, > trigger set to 400mV and horizontal position adjusted so that 400mV crosses > the center vertical graticule marking. Channel 2 is attached to the 10MHz > signal through another pass-through 50 ohm terminator. What I see on the > screen looks like 15ns delay between the triggered PPS signal and the zero > crossing 10MHz signal. My 5370B shows 18ns delay between them when the > start input level is set for 400mV. > > The manual indicates that it could take a while to see a change, but how > long is a while? My tbolt has default settings for everything except the > PPS Offset value (again, now sitting at -58ns). I expected to at least see > some change over the course of 12 hours or so, but I get nothing. Am I > completely misunderstanding something? I accidentally cycled the power > after making the settings change after the tbolt was up for a couple of > months. I learned to not use a normal serial cable with an APC ups, it cut > the power on the UPS immediately upon plugging it into the back of my PC! > Settings were verified after power was brought back up. Total downtime was > perhaps 10 seconds, but that was enough for it to lose almanac data. > > > Thanks, > Bob, N3XKB > Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Thunderbolt question regarding PPS and 10MHz phase relationship
Hello all, I'm trying to adjust the time between the leading edge of the PPS square wave and the 10MHz zero crossing outputs on a Trimble Thunderbolt. The manual seems to indicate the cable delay compensation setting will do this. As I understand things, this is also called the "PPS Offset" in the manual. I've changed this from 58ns to -58ns with no visible change over the course of a 12 hour period on a scope. My test setup is using an old Tek TDS 210 scope triggering on the PPS on channel 1 through a 50 ohm terminator, trigger set to 400mV and horizontal position adjusted so that 400mV crosses the center vertical graticule marking. Channel 2 is attached to the 10MHz signal through another pass-through 50 ohm terminator. What I see on the screen looks like 15ns delay between the triggered PPS signal and the zero crossing 10MHz signal. My 5370B shows 18ns delay between them when the start input level is set for 400mV. The manual indicates that it could take a while to see a change, but how long is a while? My tbolt has default settings for everything except the PPS Offset value (again, now sitting at -58ns). I expected to at least see some change over the course of 12 hours or so, but I get nothing. Am I completely misunderstanding something? I accidentally cycled the power after making the settings change after the tbolt was up for a couple of months. I learned to not use a normal serial cable with an APC ups, it cut the power on the UPS immediately upon plugging it into the back of my PC! Settings were verified after power was brought back up. Total downtime was perhaps 10 seconds, but that was enough for it to lose almanac data. Thanks, Bob, N3XKB ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
