Re: [time-nuts] An interesting freq counter
At 02:46 01-05-12, you wrote: that is awesome! with Transistorized Binary Unit and up to 1.1 megacycles. wow! Hand made, one by one, on Veroboard... sigh... Marco IK1ODO ___ time-nuts mailing 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] An interesting freq counter
The good old days. :-) Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: 30 April 2012 23:05 To: time-nuts@febo.com Subject: [time-nuts] An interesting freq counter With a rather freaky display that I have never seen: http://www.electricstuff.co.uk/venner.html ___ time-nuts mailing 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 no UTC offset
Hi all, I just powered on again my trimble thunderbolt after some time without antenna. All alarms are green but the obvious leap second pending. BUT: I can't use UTC time as both tboltmon and lady heather display a No UTC offset message. I don't remember having seen this in the past. What's wrong with the thunderbolt now? Many thanks in advance Frank IZ8DWF ___ time-nuts mailing 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] An interesting freq counter
On 01/05/12 11:37, Rob Kimberley wrote: The good old days. :-) My oldest counter has neon lamps behind a line of 0-9 numbers on each column. It goes to 230 KC. It has the high-stability option rather than dividing down 50 Hz to 10 Hz in the phanta-stron divider (pot on the back side to trim the division rate). Cheers, Magnus Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: 30 April 2012 23:05 To: time-nuts@febo.com Subject: [time-nuts] An interesting freq counter With a rather freaky display that I have never seen: http://www.electricstuff.co.uk/venner.html ___ time-nuts mailing 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] Ashtech 3DF GPS
On more or less of a whim, I found and bought an Ashtech 3DF GPS. The interesting thing about this particular GPS is that it uses four separate GPS antennas mounted in a diamond pattern about 1 meter on a side and can compute not only the usual stuff, but also heading, roll, and pitch angles. I had heard of this being possible, but never actually seen it done. There are no accessories included with this unit, other than the power cord. Does anyone know where I can find a manual for it? Will this GPS work with just four ordinary active antennas or are the antennas special? Given the complexity of the additional data massaging it does to extract the angular data, does this also mean that it will have more accurate position and or timing performance? Does it need all four antennas to be able to do anything at all, or can it compute position and time with just one antenna connected? Thanks, Stan ___ time-nuts mailing 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] Ashtech 3DF GPS
According to this: cedb.asce.org/cgi/WWWdisplay.cgi?80010 it seems that this GPS uses carrier phase tracking... it seems interesting. On Tue, May 1, 2012 at 3:08 PM, Stan swp...@earthlink.net wrote: On more or less of a whim, I found and bought an Ashtech 3DF GPS. The interesting thing about this particular GPS is that it uses four separate GPS antennas mounted in a diamond pattern about 1 meter on a side and can compute not only the usual stuff, but also heading, roll, and pitch angles. I had heard of this being possible, but never actually seen it done. There are no accessories included with this unit, other than the power cord. Does anyone know where I can find a manual for it? Will this GPS work with just four ordinary active antennas or are the antennas special? Given the complexity of the additional data massaging it does to extract the angular data, does this also mean that it will have more accurate position and or timing performance? Does it need all four antennas to be able to do anything at all, or can it compute position and time with just one antenna connected? Thanks, Stan ___ time-nuts mailing 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-C
Hello The Net: LORAN signals are still being received at a 89700 microsecond GRI. I concur with others that there is only one station transmitting the master(M) and the slave(X) signals. My SRS FS-700 Rx shows equal received signal strength for both signals. Reports indicate the transmitter is at the old Coast Guard LORAN engineering site at Wildwood NJ. Since I turned the equipment on last Sunday night, I have had continuous lock on the FS-700, Austron 2100, and a 2100F. Compared to the GPS/DO 10 MHz from the T'Bolt, I am getting accuracies to the mid -13s, as indicated on the FS-700 phase meter. Next step is to lock up the signal on an oscope, triggered by an accurate 11.148272 KHz signal ( reciprocal of 89700microsec). That way I should be able to see the pulses and the E-LORAN experimentation. My set up at home uses a 40' high delta loop antenna, 2 orthogonal loops terminated on the top with a 600 ohm resistor, a ARR preamplifier with battery at the antenna , a RG6 coax run to the shack, Astron 2084 multicoupler, then the receivers. Stan, W1LE Cape Cod FN41sr z ___ time-nuts mailing 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] Ashtech 3DF GPS
Hi Stan, On more or less of a whim, I found and bought an Ashtech 3DF GPS. The interesting thing about this particular GPS is that it uses four separate GPS antennas mounted in a diamond pattern about 1 meter on a side and can compute not only the usual stuff, but also heading, roll, and pitch angles. I had heard of this being possible, but never actually seen it done. There are no accessories included with this unit, other than the power cord. Does anyone know where I can find a manual for it? Look for manuals in ftp://ftp.ashtech.com/OEM,%20Sensor%20%20ADU/ perhaps it is this one? Or an earlier version. ftp://ftp.ashtech.com/OEM,%20Sensor%20%20ADU/ADU2/Reference%20Material/adu2.pdf Will this GPS work with just four ordinary active antennas or are the antennas special? Will probably work with almost any antenna, but for good performance use a geodetic quality rover antenna. Given the complexity of the additional data massaging it does to extract the angular data, does this also mean that it will have more accurate position and or timing performance? No, its specialty is to determine the relative positions of the four antennas. This will give heading, roll and pitch of the vehicle the system is mounted on. Does it need all four antennas to be able to do anything at all, or can it compute position and time with just one antenna connected? It will probably do position and time with just the master antenna connected. Thanks, Stan Good luck! -- Björn ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
Antenna envy! -John = Hello The Net: LORAN signals are still being received at a 89700 microsecond GRI. I concur with others that there is only one station transmitting the master(M) and the slave(X) signals. My SRS FS-700 Rx shows equal received signal strength for both signals. Reports indicate the transmitter is at the old Coast Guard LORAN engineering site at Wildwood NJ. Since I turned the equipment on last Sunday night, I have had continuous lock on the FS-700, Austron 2100, and a 2100F. Compared to the GPS/DO 10 MHz from the T'Bolt, I am getting accuracies to the mid -13s, as indicated on the FS-700 phase meter. Next step is to lock up the signal on an oscope, triggered by an accurate 11.148272 KHz signal ( reciprocal of 89700microsec). That way I should be able to see the pulses and the E-LORAN experimentation. My set up at home uses a 40' high delta loop antenna, 2 orthogonal loops terminated on the top with a 600 ohm resistor, a ARR preamplifier with battery at the antenna , a RG6 coax run to the shack, Astron 2084 multicoupler, then the receivers. Stan, W1LE Cape Cod FN41sr z ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
In message 1158.12.6.201.135.1335885236.squir...@popaccts.quikus.com, J. For ster writes: Next step is to lock up the signal on an oscope, triggered by an accurate 11.148272 KHz signal ( reciprocal of 89700microsec). A HP5359A is great trigger-source for that. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Ashtech 3DF GPS
These are specifically for attitude determination in mobile environments. Not sure how good they would be for timing though. I remember seeing something from Trimble a few years back which did similar. Rob K -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Stan Sent: 01 May 2012 14:08 To: time-nuts@febo.com Subject: [time-nuts] Ashtech 3DF GPS On more or less of a whim, I found and bought an Ashtech 3DF GPS. The interesting thing about this particular GPS is that it uses four separate GPS antennas mounted in a diamond pattern about 1 meter on a side and can compute not only the usual stuff, but also heading, roll, and pitch angles. I had heard of this being possible, but never actually seen it done. There are no accessories included with this unit, other than the power cord. Does anyone know where I can find a manual for it? Will this GPS work with just four ordinary active antennas or are the antennas special? Given the complexity of the additional data massaging it does to extract the angular data, does this also mean that it will have more accurate position and or timing performance? Does it need all four antennas to be able to do anything at all, or can it compute position and time with just one antenna connected? Thanks, Stan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
I should say so!! Rob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of J. Forster Sent: 01 May 2012 16:14 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] LORAN-C Antenna envy! -John = Hello The Net: LORAN signals are still being received at a 89700 microsecond GRI. I concur with others that there is only one station transmitting the master(M) and the slave(X) signals. My SRS FS-700 Rx shows equal received signal strength for both signals. Reports indicate the transmitter is at the old Coast Guard LORAN engineering site at Wildwood NJ. Since I turned the equipment on last Sunday night, I have had continuous lock on the FS-700, Austron 2100, and a 2100F. Compared to the GPS/DO 10 MHz from the T'Bolt, I am getting accuracies to the mid -13s, as indicated on the FS-700 phase meter. Next step is to lock up the signal on an oscope, triggered by an accurate 11.148272 KHz signal ( reciprocal of 89700microsec). That way I should be able to see the pulses and the E-LORAN experimentation. My set up at home uses a 40' high delta loop antenna, 2 orthogonal loops terminated on the top with a 600 ohm resistor, a ARR preamplifier with battery at the antenna , a RG6 coax run to the shack, Astron 2084 multicoupler, then the receivers. Stan, W1LE Cape Cod FN41sr z ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
Hello PHK, I will use a HP-3336C with the station 10 MHz (GPS/DO) reference. Typo: trigger should really be 11.148272 Hz instead of KHz ! Stan, W1LE On 5/1/2012 11:27 AM, Poul-Henning Kamp wrote: In message1158.12.6.201.135.1335885236.squir...@popaccts.quikus.com, J. For ster writes: Next step is to lock up the signal on an oscope, triggered by an accurate 11.148272 KHz signal ( reciprocal of 89700microsec). A HP5359A is great trigger-source for that. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
In message 4fa006e8.5040...@verizon.net, Stan, W1LE writes: I will use a HP-3336C with the station 10 MHz (GPS/DO) reference. Typo: trigger should really be 11.148272 Hz instead of KHz ! You need a really amazing stable and noise-free trigger to lock onto a 5.5Hz (see below) sine at the required level of stability (~2usec). I used my HP33120A once, but its square output is made with a comparator on the sine wave, and has pretty bad jitter. Switching to saw-tooth solved that, defining my own arbitrary square-wave was even better, not sure why. You want 1/(2*.089700) = 5.574136 Hz, otherwise every other loran-c pulse will cancel out due to the A/B coding polarity. If you don't have a counter-based signal generator, consider stealing a GRI or FRI-rate signal from one of your loran-C receivers, I belive the AUSTRON 2000/2100 offers it on a BNC at the backside. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
I use a 1.000 MHz crystal oscillator module and a Tek DD501. It produces 1 pulse every (preset count-1) of input cycles. Triggering a scope is trivial. -John = In message 4fa006e8.5040...@verizon.net, Stan, W1LE writes: I will use a HP-3336C with the station 10 MHz (GPS/DO) reference. Typo: trigger should really be 11.148272 Hz instead of KHz ! You need a really amazing stable and noise-free trigger to lock onto a 5.5Hz (see below) sine at the required level of stability (~2usec). I used my HP33120A once, but its square output is made with a comparator on the sine wave, and has pretty bad jitter. Switching to saw-tooth solved that, defining my own arbitrary square-wave was even better, not sure why. You want 1/(2*.089700) = 5.574136 Hz, otherwise every other loran-c pulse will cancel out due to the A/B coding polarity. If you don't have a counter-based signal generator, consider stealing a GRI or FRI-rate signal from one of your loran-C receivers, I belive the AUSTRON 2000/2100 offers it on a BNC at the backside. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing 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] Cs beam cavity: why is it U shaped?
Moin, For some time now, i'm wondering why the microwave cavity of Cs beam standards is U shaped. Ie why does the Cs beam fly first trough the first subcavity, leaves it, flies a substantial length trough free space, passes the second subcavity and then goes to the detector. If the interaction time with the microwave field would be an issue, i would expect the beam to pass trough a longer stretch of the cavity, and not two time trough a short stretch that are widely spaced. Unfortunately, none of the papers i've read has shed any light on this, and google isn't helpfull either. Could anyone here enlighten me? Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing 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] (Humor) - Maybe they need some time nuts..
85 minutes in that hour... http://www.taylorusa.com/dual-event-timer-clock.html ___ time-nuts mailing 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] Cs beam cavity: why is it U shaped?
The U shape is called the Ramsey Cavity: http://www.nobelprize.org/nobel_prizes/physics/laureates/1989/ramsey-lecture.pdf /tvb - Original Message - From: Attila Kinali att...@kinali.ch To: time-nuts@febo.com Sent: Tuesday, May 01, 2012 9:47 AM Subject: [time-nuts] Cs beam cavity: why is it U shaped? Moin, For some time now, i'm wondering why the microwave cavity of Cs beam standards is U shaped. Ie why does the Cs beam fly first trough the first subcavity, leaves it, flies a substantial length trough free space, passes the second subcavity and then goes to the detector. If the interaction time with the microwave field would be an issue, i would expect the beam to pass trough a longer stretch of the cavity, and not two time trough a short stretch that are widely spaced. Unfortunately, none of the papers i've read has shed any light on this, and google isn't helpfull either. Could anyone here enlighten me? Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing 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] (Humor) - Maybe they need some time nuts..
Metric minutes. On 05/01/12, Don Barrdon.b...@gmail.com wrote: 85 minutes in that hour... [1]http://www.taylorusa.com/dual-event-timer-clock.html ___ time-nuts mailing list -- [2]time-nuts@febo.com To unsubscribe, go to [3]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. http://www.taylorusa.com/dual-event-timer-clock.html 2. mailto:time-nuts@febo.com 3. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing 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] Symmetricom TimeSource 2700
Hi The upstream time source may or may not be very good. Since it's PCS at 1.9 GHz and not 900 MHz CDMA, the carriers have a lot of wiggle room. You can go in and fiddle which signal it tracks. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Spencer Sent: Tuesday, May 01, 2012 12:41 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Symmetricom TimeSource 2700 Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer --- On Thu, 11/24/11, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: From: Charles P. Steinmetz charles_steinm...@lavabit.com Subject: Re: [time-nuts] Symmetricom TimeSource 2700 To: Discussion of precise time and frequency measurement time-nuts@febo.com Received: Thursday, November 24, 2011, 11:17 PM Kevin wrote: I use the Craft connector for monitoring with BTMon rather than the RS-232 port. It appears the Craft output, while spontaneously emitting alarm/events, does respond to queries from BTMon on the Craft input. Everything I reported previously involved the Craft port feeding a PC COM port using the RJ45-to-DB9 cable supplied by Symmetricom. Do you happen to have a RS-422/485 interface? I don't, but I'm interested to see if any spontaneous output occurs on the TOD port. I have a 422/485 card here somewhere, but I haven't used it (maybe even seen it) in more than 10 years. I poked a scope at the TOD jack. The TS2500 manual says that (in a TS2500) Pin 1 should be PPS (positive), Pin 6 should be PPS (negative), Pin 5 should be TXA output (positive), Pin 9 should be TXA output (negative), and Pins 7 and 3 should be a 20 V external supply positive and return, respectively. I found PPS positive and negative on Pins 1 and 6. Logic low is about 1.2 V positive with respect to case ground, and logic high is about 3.8 V above case ground, for a logic range of approximately 2.6 V. The PPS pulses are 500 uS wide with rise and fall times of ~20-25 nS. I did not see any data on the TXA outputs -- the positive TXA output just sits at logic low and the negative TXA output sits at logic high. There is 20 V between Pins 7 and 3. As for the unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins 4 and 8 sit at nominally 0.168 Vdc. All three have around 20 mVp-p of hum and noise. While I was at it, I poked at the RS232 connector, as well. Pin 3 (TX Data) has a 16 or 17 mS burst of data every 5 seconds (approximately), from -10 V to +10 V with respect to case (henceforth, 232 low and high, respectively). Between bursts, it sits at 232 low. Pins 4 and 7 (DTR and RTS, respectively) sit at 232 high. All other pins sit at ground. 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 no UTC offset
francesco.messi...@gmail.com said: I just powered on again my trimble thunderbolt after some time without antenna. All alarms are green but the obvious leap second pending. BUT: I can't use UTC time as both tboltmon and lady heather display a No UTC offset message. I don't remember having seen this in the past. What's wrong with the thunderbolt now? How long has it been on? The UTC offset comes from the satellites. I think it is only sent every hour. -- 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 no UTC offset
Hi Hal, On 5/1/12, Hal Murray hmur...@megapathdsl.net wrote: francesco.messi...@gmail.com said: I just powered on again my trimble thunderbolt after some time without antenna. All alarms are green but the obvious leap second pending. BUT: I can't use UTC time as both tboltmon and lady heather display a No UTC offset message. I don't remember having seen this in the past. What's wrong with the thunderbolt now? How long has it been on? The UTC offset comes from the satellites. I think it is only sent every hour. yes indeed, it was ok after about 1 hour of the power up. Sorry but I didn't remember I had ever waited so long for the UTC to come on. I'm now plotting the signal strength vs AZ/EL map, I'll post the result tomorrow so maybe someone can tell me how the new antenna is working. Thanks Frank IZ8DWF ___ time-nuts mailing 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] Cs beam cavity: why is it U shaped?
Hi Attila, On 05/01/2012 06:47 PM, Attila Kinali wrote: Moin, For some time now, i'm wondering why the microwave cavity of Cs beam standards is U shaped. Ie why does the Cs beam fly first trough the first subcavity, leaves it, flies a substantial length trough free space, passes the second subcavity and then goes to the detector. If the interaction time with the microwave field would be an issue, i would expect the beam to pass trough a longer stretch of the cavity, and not two time trough a short stretch that are widely spaced. Unfortunately, none of the papers i've read has shed any light on this, and google isn't helpfull either. Could anyone here enlighten me? In combination with Tom's link to the Noble lecture, the U-shaped form is really a bent transmission line such that the same source provides the same signal. It's also important that the phase delay from the source to both branches be very closely matched. Miss-align them and you get a systematic frequency error as a result. Notice how the RF interaction has the RF field being oriented orthogonally to the direction of the beam. 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] Cs beam cavity: why is it U shaped?
The tube is like an interferometer. Think of two telescopes spaced apart x meters. It has the resolving power of an x meter diameter telescope. It doesn't have the light gathering power of an x meter telescope. There is sufficient RF power to flip the state of all the Cs atoms, so additional interaction time would not be helpful. Also, the accuracy of the standard depends on the phase error between the two ends. (The big machines send the beam through in both directions to cancel this out). There is no way to do this (AFAIK) if you had to excite the atoms over their entire flight. In the 5071 CBT, there are proprietary manufacturing techniques that reduce the random phase error to parts in 10^13 and the systematic phase error to parts in 10^14, or so I have been told. This cleverness is the kind of thing that gets noticed in Stockholm. Rick Karlquist, N6RK Attila Kinali wrote: Moin, For some time now, i'm wondering why the microwave cavity of Cs beam standards is U shaped. Ie why does the Cs beam fly first trough the first subcavity, leaves it, flies a substantial length trough free space, passes the second subcavity and then goes to the detector. If the interaction time with the microwave field would be an issue, i would expect the beam to pass trough a longer stretch of the cavity, and not two time trough a short stretch that are widely spaced. Unfortunately, none of the papers i've read has shed any light on this, and google isn't helpfull either. Could anyone here enlighten me? Attila Kinali -- Why does it take years to find the answers to the questions one should have asked long ago? ___ time-nuts mailing 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 no UTC offset
Incorrect, the UTC offset should be sent in the Almanac, the Almanac having a period of 12.5 minutes max. Not one hour. It should take no more than 12.5 minutes to get the UTC offset when sats are properly being received. bye, Said In a message dated 5/1/2012 11:45:06 Pacific Daylight Time, francesco.messi...@gmail.com writes: Hi Hal, On 5/1/12, Hal Murray hmur...@megapathdsl.net wrote: francesco.messi...@gmail.com said: I just powered on again my trimble thunderbolt after some time without antenna. All alarms are green but the obvious leap second pending. BUT: I can't use UTC time as both tboltmon and lady heather display a No UTC offset message. I don't remember having seen this in the past. What's wrong with the thunderbolt now? How long has it been on? The UTC offset comes from the satellites. I think it is only sent every hour. yes indeed, it was ok after about 1 hour of the power up. Sorry but I didn't remember I had ever waited so long for the UTC to come on. I'm now plotting the signal strength vs AZ/EL map, I'll post the result tomorrow so maybe someone can tell me how the new antenna is working. Thanks Frank IZ8DWF ___ time-nuts mailing 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] Symmetricom TimeSource 2700
The problem is I don't have the software for the unit, but based on the behaviour of the alarm and status led's I'm confident it is locked. The symmetricom site may have the software but I would need to agree to an eula prior to downloading which I don't want to do with my work account. So far symmetricom hasn't approved my request for a personal log in to their site. I may try again with another email address (: -- On Tue, 1 May, 2012 2:31 PM EDT Bob Camp wrote: Hi The upstream time source may or may not be very good. Since it's PCS at 1.9 GHz and not 900 MHz CDMA, the carriers have a lot of wiggle room. You can go in and fiddle which signal it tracks. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Spencer Sent: Tuesday, May 01, 2012 12:41 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Symmetricom TimeSource 2700 Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer --- On Thu, 11/24/11, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: From: Charles P. Steinmetz charles_steinm...@lavabit.com Subject: Re: [time-nuts] Symmetricom TimeSource 2700 To: Discussion of precise time and frequency measurement time-nuts@febo.com Received: Thursday, November 24, 2011, 11:17 PM Kevin wrote: I use the Craft connector for monitoring with BTMon rather than the RS-232 port. It appears the Craft output, while spontaneously emitting alarm/events, does respond to queries from BTMon on the Craft input. Everything I reported previously involved the Craft port feeding a PC COM port using the RJ45-to-DB9 cable supplied by Symmetricom. Do you happen to have a RS-422/485 interface? I don't, but I'm interested to see if any spontaneous output occurs on the TOD port. I have a 422/485 card here somewhere, but I haven't used it (maybe even seen it) in more than 10 years. I poked a scope at the TOD jack. The TS2500 manual says that (in a TS2500) Pin 1 should be PPS (positive), Pin 6 should be PPS (negative), Pin 5 should be TXA output (positive), Pin 9 should be TXA output (negative), and Pins 7 and 3 should be a 20 V external supply positive and return, respectively. I found PPS positive and negative on Pins 1 and 6. Logic low is about 1.2 V positive with respect to case ground, and logic high is about 3.8 V above case ground, for a logic range of approximately 2.6 V. The PPS pulses are 500 uS wide with rise and fall times of ~20-25 nS. I did not see any data on the TXA outputs -- the positive TXA output just sits at logic low and the negative TXA output sits at logic high. There is 20 V between Pins 7 and 3. As for the unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins 4 and 8 sit at nominally 0.168 Vdc. All three have around 20 mVp-p of hum and noise. While I was at it, I poked at the RS232 connector, as well. Pin 3 (TX Data) has a 16 or 17 mS burst of data every 5 seconds (approximately), from -10 V to +10 V with respect to case (henceforth, 232 low and high, respectively). Between bursts, it sits at 232 low. Pins 4 and 7 (DTR and RTS, respectively) sit at 232 high. All other pins sit at ground. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
Re: [time-nuts] Symmetricom TimeSource 2700
Hello Mark, you could connect the Fury 1PPS output to the 1PPS external sync input of the PRS-10 Rb and let is self-discipline to GPS. Set the Fury 1PPS jumper JP4 to raw-1PPS (pins 2 and 3), and that will make the Fury GPSDO generate the raw 1PPS signal from the Motorola GPS receiver albeit without sawtooth correction. You won't need sawtooth correction if you set the PRS-10 time constant to say 10,000 seconds. bye, Said In a message dated 5/1/2012 10:55:34 Pacific Daylight Time, mspencer12...@yahoo.ca writes: Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer ___ time-nuts mailing 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 no UTC offset
On 5/1/12, saidj...@aol.com saidj...@aol.com wrote: Incorrect, the UTC offset should be sent in the Almanac, the Almanac having a period of 12.5 minutes max. Not one hour. It should take no more than 12.5 minutes to get the UTC offset when sats are properly being received. when I posted my original enquiry, the almanac alarm had turned green since quite some time already, that's why I was wondering what could be wrong. Best regards Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
Hello PHK, Thanks for the tips. I have not done this yet, so I am creeping along. I also have a 33120A with the the option 001 for using an external reference. Sounds like the arbitrary signal capability is the way to go, If I can not find an appropriate 2100/2100F output. Thanks Stan, W1LE Cape Cod On 5/1/2012 12:02 PM, Poul-Henning Kamp wrote: In message4fa006e8.5040...@verizon.net, Stan, W1LE writes: I will use a HP-3336C with the station 10 MHz (GPS/DO) reference. Typo: trigger should really be 11.148272 Hz instead of KHz ! You need a really amazing stable and noise-free trigger to lock onto a 5.5Hz (see below) sine at the required level of stability (~2usec). I used my HP33120A once, but its square output is made with a comparator on the sine wave, and has pretty bad jitter. Switching to saw-tooth solved that, defining my own arbitrary square-wave was even better, not sure why. You want 1/(2*.089700) = 5.574136 Hz, otherwise every other loran-c pulse will cancel out due to the A/B coding polarity. If you don't have a counter-based signal generator, consider stealing a GRI or FRI-rate signal from one of your loran-C receivers, I belive the AUSTRON 2000/2100 offers it on a BNC at the backside. ___ time-nuts mailing 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] (Humor) - Maybe they need some time nuts..
PhotoShop. -John === Metric minutes. On 05/01/12, Don Barrdon.b...@gmail.com wrote: 85 minutes in that hour... [1]http://www.taylorusa.com/dual-event-timer-clock.html ___ time-nuts mailing list -- [2]time-nuts@febo.com To unsubscribe, go to [3]https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. References 1. http://www.taylorusa.com/dual-event-timer-clock.html 2. mailto:time-nuts@febo.com 3. https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing 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 no UTC offset
From memory, the UTC offset is part of the Supplemental data packet that is sent every second by default. Didier KO4BB Sent from my BlackBerry Wireless thingy while I do other things... -Original Message- From: Hal Murray hmur...@megapathdsl.net Sender: time-nuts-boun...@febo.com Date: Tue, 01 May 2012 11:41:22 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] thunderbolt no UTC offset francesco.messi...@gmail.com said: I just powered on again my trimble thunderbolt after some time without antenna. All alarms are green but the obvious leap second pending. BUT: I can't use UTC time as both tboltmon and lady heather display a No UTC offset message. I don't remember having seen this in the past. What's wrong with the thunderbolt now? How long has it been on? The UTC offset comes from the satellites. I think it is only sent every hour. -- 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. ___ time-nuts mailing 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 no UTC offset
The UTC offset is in words 6-10, page 18, subframe 4 -- every 12.5 minutes. /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.
[time-nuts] FEI-Zyfer
Anyone have a manual for an FEI-Zyfer Nanosync II? It's listed on their website, but clicking on the link throws up a 404 error Tnx, Mike A closed mouth gathers no feet ___ time-nuts mailing 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 no UTC offset
On 05/01/2012 10:30 PM, Tom Van Baak wrote: The UTC offset is in words 6-10, page 18, subframe 4 -- every 12.5 minutes. It was added to the broadcast signal as an after-thought, as a separate upgrade package if you wish. At least back then, I believe they had USNO to measure the GPS time and provide corrections to match up with USNO UTC scale. It makes sense that they still do that. The publish differences is really just a hand-full of ns. The GPS time is to be maintained within +/- 1 us of the USNO UTC time-scale according to original setup. Does anyone has any more recent descriptions on this? Besides the track record being available from USNO or for that matter the BIPM. 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] FEI-Zyfer
Hi guys, I was able to simply register at the site then had access to another file are that had info on the Nanosync II and their monitor software. Mike - Original Message - From: Mike Seguin N1JEZ n1...@burlingtontelecom.net Subject: [time-nuts] FEI-Zyfer Anyone have a manual for an FEI-Zyfer Nanosync II? It's listed on their website, but clicking on the link throws up a 404 error Tnx, Mike A closed mouth gathers no feet ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] LORAN-C
I have not been able to do anything work and a strong investment in time in plumbing this week. Hey you have to fix'em occasionally. Regards Paul. On Tue, May 1, 2012 at 3:16 PM, Stan, W1LE stanw...@verizon.net wrote: Hello PHK, Thanks for the tips. I have not done this yet, so I am creeping along. I also have a 33120A with the the option 001 for using an external reference. Sounds like the arbitrary signal capability is the way to go, If I can not find an appropriate 2100/2100F output. Thanks Stan, W1LE Cape Cod On 5/1/2012 12:02 PM, Poul-Henning Kamp wrote: In message4FA006E8.5040304@**verizon.net 4fa006e8.5040...@verizon.net, Stan, W1LE writes: I will use a HP-3336C with the station 10 MHz (GPS/DO) reference. Typo: trigger should really be 11.148272 Hz instead of KHz ! You need a really amazing stable and noise-free trigger to lock onto a 5.5Hz (see below) sine at the required level of stability (~2usec). I used my HP33120A once, but its square output is made with a comparator on the sine wave, and has pretty bad jitter. Switching to saw-tooth solved that, defining my own arbitrary square-wave was even better, not sure why. You want 1/(2*.089700) = 5.574136 Hz, otherwise every other loran-c pulse will cancel out due to the A/B coding polarity. If you don't have a counter-based signal generator, consider stealing a GRI or FRI-rate signal from one of your loran-C receivers, I belive the AUSTRON 2000/2100 offers it on a BNC at the backside. __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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] Symmetricom TimeSource 2700
I am playing around with a OT-20 Office Time that I pulled out of a dumpster some time ago. I've only just powered it up last weekend and it without an antenna will illuminate its CDMA green status LED in about 10 minutes. I've not tried an antenna or hooked up a terminal to its serial port. -pete On Tue, May 1, 2012 at 9:40 AM, Mark Spencer mspencer12...@yahoo.ca wrote: Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer --- On Thu, 11/24/11, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: From: Charles P. Steinmetz charles_steinm...@lavabit.com Subject: Re: [time-nuts] Symmetricom TimeSource 2700 To: Discussion of precise time and frequency measurement time-nuts@febo.com Received: Thursday, November 24, 2011, 11:17 PM Kevin wrote: I use the Craft connector for monitoring with BTMon rather than the RS-232 port. It appears the Craft output, while spontaneously emitting alarm/events, does respond to queries from BTMon on the Craft input. Everything I reported previously involved the Craft port feeding a PC COM port using the RJ45-to-DB9 cable supplied by Symmetricom. Do you happen to have a RS-422/485 interface? I don't, but I'm interested to see if any spontaneous output occurs on the TOD port. I have a 422/485 card here somewhere, but I haven't used it (maybe even seen it) in more than 10 years. I poked a scope at the TOD jack. The TS2500 manual says that (in a TS2500) Pin 1 should be PPS (positive), Pin 6 should be PPS (negative), Pin 5 should be TXA output (positive), Pin 9 should be TXA output (negative), and Pins 7 and 3 should be a 20 V external supply positive and return, respectively. I found PPS positive and negative on Pins 1 and 6. Logic low is about 1.2 V positive with respect to case ground, and logic high is about 3.8 V above case ground, for a logic range of approximately 2.6 V. The PPS pulses are 500 uS wide with rise and fall times of ~20-25 nS. I did not see any data on the TXA outputs -- the positive TXA output just sits at logic low and the negative TXA output sits at logic high. There is 20 V between Pins 7 and 3. As for the unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins 4 and 8 sit at nominally 0.168 Vdc. All three have around 20 mVp-p of hum and noise. While I was at it, I poked at the RS232 connector, as well. Pin 3 (TX Data) has a 16 or 17 mS burst of data every 5 seconds (approximately), from -10 V to +10 V with respect to case (henceforth, 232 low and high, respectively). Between bursts, it sits at 232 low. Pins 4 and 7 (DTR and RTS, respectively) sit at 232 high. All other pins sit at ground. 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. ___ time-nuts mailing 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] Symmetricom TimeSource 2700
Thought the cdma signals were all gone. On Tue, May 1, 2012 at 6:50 PM, Pete Lancashire p...@petelancashire.comwrote: I am playing around with a OT-20 Office Time that I pulled out of a dumpster some time ago. I've only just powered it up last weekend and it without an antenna will illuminate its CDMA green status LED in about 10 minutes. I've not tried an antenna or hooked up a terminal to its serial port. -pete On Tue, May 1, 2012 at 9:40 AM, Mark Spencer mspencer12...@yahoo.ca wrote: Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer --- On Thu, 11/24/11, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: From: Charles P. Steinmetz charles_steinm...@lavabit.com Subject: Re: [time-nuts] Symmetricom TimeSource 2700 To: Discussion of precise time and frequency measurement time-nuts@febo.com Received: Thursday, November 24, 2011, 11:17 PM Kevin wrote: I use the Craft connector for monitoring with BTMon rather than the RS-232 port. It appears the Craft output, while spontaneously emitting alarm/events, does respond to queries from BTMon on the Craft input. Everything I reported previously involved the Craft port feeding a PC COM port using the RJ45-to-DB9 cable supplied by Symmetricom. Do you happen to have a RS-422/485 interface? I don't, but I'm interested to see if any spontaneous output occurs on the TOD port. I have a 422/485 card here somewhere, but I haven't used it (maybe even seen it) in more than 10 years. I poked a scope at the TOD jack. The TS2500 manual says that (in a TS2500) Pin 1 should be PPS (positive), Pin 6 should be PPS (negative), Pin 5 should be TXA output (positive), Pin 9 should be TXA output (negative), and Pins 7 and 3 should be a 20 V external supply positive and return, respectively. I found PPS positive and negative on Pins 1 and 6. Logic low is about 1.2 V positive with respect to case ground, and logic high is about 3.8 V above case ground, for a logic range of approximately 2.6 V. The PPS pulses are 500 uS wide with rise and fall times of ~20-25 nS. I did not see any data on the TXA outputs -- the positive TXA output just sits at logic low and the negative TXA output sits at logic high. There is 20 V between Pins 7 and 3. As for the unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins 4 and 8 sit at nominally 0.168 Vdc. All three have around 20 mVp-p of hum and noise. While I was at it, I poked at the RS232 connector, as well. Pin 3 (TX Data) has a 16 or 17 mS burst of data every 5 seconds (approximately), from -10 V to +10 V with respect to case (henceforth, 232 low and high, respectively). Between bursts, it sits at 232 low. Pins 4 and 7 (DTR and RTS, respectively) sit at 232 high. All other pins sit at ground. 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. ___ time-nuts mailing list --
Re: [time-nuts] Symmetricom TimeSource 2700
Hi CDMA is very much alive and kicking in the US. Bob On May 1, 2012, at 7:00 PM, paul swed wrote: Thought the cdma signals were all gone. On Tue, May 1, 2012 at 6:50 PM, Pete Lancashire p...@petelancashire.comwrote: I am playing around with a OT-20 Office Time that I pulled out of a dumpster some time ago. I've only just powered it up last weekend and it without an antenna will illuminate its CDMA green status LED in about 10 minutes. I've not tried an antenna or hooked up a terminal to its serial port. -pete On Tue, May 1, 2012 at 9:40 AM, Mark Spencer mspencer12...@yahoo.ca wrote: Sorry to resurrect an old thread, but I thought someone might find this of interest. I purchased a 2700 intending to harvest the PRS10. Prior to cracking open the case I powered up the unit to ensure it was basically working so I could return it if needed. I noticed that despite not having an antenna connected it seemed to find and track CDMA signals and after a few hours the 10 Mhz output was in a few parts of 10E-12 of my GPSD0. After a bit of investigation I found the following Adding an external antenna didn't seem to make much difference to the performance. The 1pps output is approx. 75ms out of sync with the 1pps output from my Fury GPSD0. From time to time the 10 Mhz output experiences phase jumps of several tens of ns. Manipulating the unit (ie. connecting to the RS 422 port) may induce this. Power cycling the unit seems to cure the problem and the unit usually takes an hour or two to re lock. It's possible that the lack of a proper ground in my instalation may be causing some of the issues as well. This problem would be a show stopper for me in terms of using this unit to replace my GPSDO's. I'm not sure if this issue is specfic to my unit or not. I've attached some initial ADEV plots showing the typical performance of the 10 Mhz output vs three of my other references. (I wouldn't put a lot of emphasis on the results of taus of less than 100 seconds or more than 6,000 or so..) I doubt I'm going to put much more time into this unit but it's an interesting novelty in it's original state. The results of other units may well differ (: Regards Mark Spencer --- On Thu, 11/24/11, Charles P. Steinmetz charles_steinm...@lavabit.com wrote: From: Charles P. Steinmetz charles_steinm...@lavabit.com Subject: Re: [time-nuts] Symmetricom TimeSource 2700 To: Discussion of precise time and frequency measurement time-nuts@febo.com Received: Thursday, November 24, 2011, 11:17 PM Kevin wrote: I use the Craft connector for monitoring with BTMon rather than the RS-232 port. It appears the Craft output, while spontaneously emitting alarm/events, does respond to queries from BTMon on the Craft input. Everything I reported previously involved the Craft port feeding a PC COM port using the RJ45-to-DB9 cable supplied by Symmetricom. Do you happen to have a RS-422/485 interface? I don't, but I'm interested to see if any spontaneous output occurs on the TOD port. I have a 422/485 card here somewhere, but I haven't used it (maybe even seen it) in more than 10 years. I poked a scope at the TOD jack. The TS2500 manual says that (in a TS2500) Pin 1 should be PPS (positive), Pin 6 should be PPS (negative), Pin 5 should be TXA output (positive), Pin 9 should be TXA output (negative), and Pins 7 and 3 should be a 20 V external supply positive and return, respectively. I found PPS positive and negative on Pins 1 and 6. Logic low is about 1.2 V positive with respect to case ground, and logic high is about 3.8 V above case ground, for a logic range of approximately 2.6 V. The PPS pulses are 500 uS wide with rise and fall times of ~20-25 nS. I did not see any data on the TXA outputs -- the positive TXA output just sits at logic low and the negative TXA output sits at logic high. There is 20 V between Pins 7 and 3. As for the unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins 4 and 8 sit at nominally 0.168 Vdc. All three have around 20 mVp-p of hum and noise. While I was at it, I poked at the RS232 connector, as well. Pin 3 (TX Data) has a 16 or 17 mS burst of data every 5 seconds (approximately), from -10 V to +10 V with respect to case (henceforth, 232 low and high, respectively). Between bursts, it sits at 232 low. Pins 4 and 7 (DTR and RTS, respectively) sit at 232 high. All other pins sit at ground. 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 no UTC offset
On 2 May, 2012, at 04:30 , Tom Van Baak wrote: The UTC offset is in words 6-10, page 18, subframe 4 -- every 12.5 minutes. /tvb The leap second warning is also in the same place. How the unit could know that a leap second is pending but not know the UTC offset is a mystery. Dennis Ferguson ___ time-nuts mailing 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] Sw for pm6680B
Hi Nigel, Magnus, Bjorn the Gang, Thanks for all your replies to my initial message, I appreciate very much. I downloaded the lastest version of TimeLab and will try it soon, I just tested the counter against my 5370B and my different Rubidium sources. Nigel, if you're referring to the 6680B which was on The Frenchy Bay last week, yes it's me, sorry if you were also on the deal... I would have preferred a PM6681, but no luck, it was a 6680B version, may be one day if necessary, don't know yet if it's. The old mummy arrived some days ago, I tested it, it works great, at least the basic function I tested. The OCXO has to be tuned properly, however as I'll use it in the lab driven by a PRS10 Rubidium 1pps synchronized with a Z3816 GPS rig so it's not a big issue. The question I'm wondering : Does the PM6680B (or PM6681B) replace completely a 5370B? My two main problems with the 5370B are the noise and the heat (then the AC consumption)! Also the 5370B on the bench is much more heavy compared to the PM6680B... So I'm not sure if one replace the other, so keeping the 5370B is certainly preferable?... Don't know... :-\ Your advises are welcome. All the bests to all of you and enjoy your toys... pf, f5bqp ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
