[time-nuts] wtb:Trimble svee6
Title says it all. Need it for a Datum ts2100. The command set is different between the svee6 and the ACEIII. Norm n3ykf ___ time-nuts mailing 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] How are iPhones' clocks set under LTE?
From: Paul This is an acknowledged design flaw on their part. It will only choose a user provided clock if the default pool is unavailable (short or long term). ___ Very helpful chap/bunch at Emerald. Seems to work correctly here - my local stratum 1 server is displayed if it's reachable (i.e. I'm on my local network). Mind you, it was I who asked for the feature! Choose sounds like it might be syncing against that clock - it doesn't, of course, just displays the iPad time versus NTP time, whilst showing a big clock in UTC or local time. For my Android phone I use ClockSync, again to read rather than set the clock as my phone isn't rooted. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tektronix TM500 extender cable kit
No, you also need a GPIB extender cable for FULL function ... Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of R.Phillips Sent: 04 August 2014 17:11 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Tektronix TM500 extender cable kit Am I right in thinking that two of these connector/cables would give the full facilities on the 5000 series units. Roy ___ time-nuts mailing 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] How are iPhones' clocks set under LTE?
FWIW, since I downloaded Emerald Time a couple days ago, I have not observed an offset of my iPhone's clock from UTC(NTP) of greater than one second. My carrier is T-Mobile. I'll keep watching to see if it stays this good. Sent from my iPhone ___ time-nuts mailing 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] FTS1000A 05818-501 spec's
Hello, all I went a bit overboard on ebay and ended up with a FTS1000A model 05818-501. I've found the datasheet for the FTS1000 on ko4bb's site, but the model numbers does not match up. Does anyone know the spec for this particular model (phasenoise/stability), and if there's reason to suspect that the pinout is different for this particular model? Thank you all! ___ time-nuts mailing 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] How are iPhones' clocks set under LTE?
On Tue, Aug 5, 2014 at 3:24 AM, David J Taylor david-tay...@blueyonder.co.uk wrote: Seems to work correctly here - my local stratum 1 server is displayed if it's reachable (i.e. I'm on my local network). In the US it tries [0-3].us.pool and my local address. It chooses the best three of those and then it chooses one. The list also shows (in pool.ntp.org) [0-3], europe, north-america. asia. oceania, south-america and time.apple.com in that order. Is it the same in the UK? In March 2013 (it seems longer ago): ET asynchronously sends an NTP request to each of 4 or 5 hosts. It then requests additional samples from each host until it gets enough good samples from at least one host. It then picks the host whose times were most consistent (the lowest sigma value in the stats display). Since all this is happening asynchronously we may stop before getting a full complement of responses from each host. And it may not be the host with the lowest RTT. ET was our first app that uses NTP. We have since switched to a different algorithm for picking which server to use in our other apps. But so far the new algorithm hasn't been incorporated into ET. William Arnett Emerald Sequoia LLC ___ time-nuts mailing 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] How are iPhones' clocks set under LTE?
From: Paul In the US it tries [0-3].us.pool and my local address. It chooses the best three of those and then it chooses one. The list also shows (in pool.ntp.org) [0-3], europe, north-america. asia. oceania, south-america and time.apple.com in that order. Is it the same in the UK? Thanks, Paul. On checking, mine does exactly the same, and my own local stratum-1 server sometimes ends up with a sigma of , and is not chosen. I now appreciate what you mean by chosen - selected as the comparison source. As William Arnett says - could do better. Perhaps you and I should remind them about that - they have responded to other requests on mine in the past. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tektronix TM500 extender cable kit
I knew about the GPIB but since I don't use it 99% of the time its not a challenge especially since the only reason I extend a module is to fix it. I did not know that there were 3 bay modules. Learn something every day. But don't own one. Regards Paul WB8TSL On Tue, Aug 5, 2014 at 5:37 AM, David C. Partridge david.partri...@perdrix.co.uk wrote: No, you also need a GPIB extender cable for FULL function ... Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of R.Phillips Sent: 04 August 2014 17:11 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Tektronix TM500 extender cable kit Am I right in thinking that two of these connector/cables would give the full facilities on the 5000 series units. Roy ___ time-nuts mailing 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] time-nuts Digest, Vol 121, Issue 8
On 8/4/2014 8:23 PM, Brian Garrett garrettbrian1...@gmail.com wrote: Heh, absolutely correct. many 'cell towers' (officially BTS's in GSM or (e)NodeB's in LTE) can be controlled by one controller, up to hundreds per. If you're near a TZ boundary, the controller (which is where the location info comes from) can be in a different TZ. I've heard that people who live near time zone boundaries (very near, like within a mile or two) often have to switch automatic setting off, because the time might be an hour off depending on which tower their phone connects to. the annual switches to and from daylight saving time can cause one-hour discrepancies too. Fortunately, in this case, turning automatic setting off and then turning it back on forces a re-sync, thus supplying your phone with the right time. -- Bill Ezell -- The day Microsoft makes something that doesn't suck will be the day they make vacuum cleaners. ___ time-nuts mailing 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] Effects of noise on EFC line?
I've run into a noise problem on the EFC line of my GPSDO engine at the frequency of the oscillator. I've traced the source down to the 74HCT365 I'm using to output the 1(or 5)MHz and 10MHz signals. When I pull it, the EFC quietens down a lot. I'm seeing about 50mv of 10MHz noise at the output of the op-amp that feeds the EFC voltage divider at the OCXO. The voltage divider is corrected by the VRef from the OCXO with a simple circuit using temp-co'ed resistors. On the 0.1uf cap at the OCXO's EFC pin, I'm seeing about 5mv of 10MHz signal. I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? I'm also wondering what the impact of this level of on-frequency noise will be? Is the impact somewhat mitigated, since it's at oscillator frequency? I don't have anything better than an HP 8558B to look at the output of the board. I'm not quite ready to generally share my schematic with the list, but I can make individual exceptions. Bob - AE6RV ___ time-nuts mailing 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] Effects of noise on EFC line?
OK my 2 cents and others will have better comments. You can use a far larger inductor in the efc line to try to reduce the noise. EFCs tend to be integrated by some cap. So they are slow moving compared to the noise. Better design is separate analog and digital supplies. Regards Paul WB8TSL On Tue, Aug 5, 2014 at 2:36 PM, Bob Stewart b...@evoria.net wrote: I've run into a noise problem on the EFC line of my GPSDO engine at the frequency of the oscillator. I've traced the source down to the 74HCT365 I'm using to output the 1(or 5)MHz and 10MHz signals. When I pull it, the EFC quietens down a lot. I'm seeing about 50mv of 10MHz noise at the output of the op-amp that feeds the EFC voltage divider at the OCXO. The voltage divider is corrected by the VRef from the OCXO with a simple circuit using temp-co'ed resistors. On the 0.1uf cap at the OCXO's EFC pin, I'm seeing about 5mv of 10MHz signal. I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? I'm also wondering what the impact of this level of on-frequency noise will be? Is the impact somewhat mitigated, since it's at oscillator frequency? I don't have anything better than an HP 8558B to look at the output of the board. I'm not quite ready to generally share my schematic with the list, but I can make individual exceptions. Bob - AE6RV ___ time-nuts mailing 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] Effects of noise on EFC line?
I was able to quiet things down a lot by putting a 100 ohm resistor in series with the 74HC output. If these guys drive more than a few inches of wire, they ring like crazy. Also make sure you pay close attention to the bypassing of the 5V supply. Make your bypass cap lead lengths as short as possible. On Tue, Aug 5, 2014 at 2:36 PM, Bob Stewart b...@evoria.net wrote: I've run into a noise problem on the EFC line of my GPSDO engine at the frequency of the oscillator. I've traced the source down to the 74HCT365 I'm using to output the 1(or 5)MHz and 10MHz signals. When I pull it, the EFC quietens down a lot. I'm seeing about 50mv of 10MHz noise at the output of the op-amp that feeds the EFC voltage divider at the OCXO. The voltage divider is corrected by the VRef from the OCXO with a simple circuit using temp-co'ed resistors. On the 0.1uf cap at the OCXO's EFC pin, I'm seeing about 5mv of 10MHz signal. I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? I'm also wondering what the impact of this level of on-frequency noise will be? Is the impact somewhat mitigated, since it's at oscillator frequency? I don't have anything better than an HP 8558B to look at the output of the board. I'm not quite ready to generally share my schematic with the list, but I can make individual exceptions. Bob - AE6RV ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- --Jim Harman ___ time-nuts mailing 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] Effects of noise on EFC line?
On Tue, Aug 5, 2014 at 11:36 AM, Bob Stewart b...@evoria.net wrote: I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? Not just an inductor but a low pass filter (maybe CLC) designed reject anything outside the bandwidth of your control signal. How often do you update the EFC? Once per second? then your bandwidth is 0.5 Hz. That EFC is very close to DC if your uP is only updating EFC once per second. Your filter should be physically close to the OCXO and have a very large time constant. In addition to this I have a 0.1uF cap soldered directly to the EFC and Ground pins of the OCXO. You say you have detected 10MHz noise, but you can bet there is some 60Hz too. About Vcc, I assume each chip has a bypass that is physically right on the Vcc pin. That is enough. Well almost. You need a digital and an analog power supply, sort of. Don't power both off the same voltage regulator. They can share a transformer But make sure the digital stuff has it's own power rail and it's own voltage reg. Then you do the same with the grounds, digital and analog and tie them together at one place near the power supply. Tuns out these GPSDOs are way-simple now. Just a few parts needed. You can use a serial interface DAC to drive EFC. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Effects of noise on EFC line?
and use not to large capacity, because above the serial resonance frequency [trace inductance, own inductance] it will be inductive! 73 Alex KJ6UHN On 8/5/2014 12:16 PM, Jim Harman wrote: I was able to quiet things down a lot by putting a 100 ohm resistor in series with the 74HC output. If these guys drive more than a few inches of wire, they ring like crazy. Also make sure you pay close attention to the bypassing of the 5V supply. Make your bypass cap lead lengths as short as possible. On Tue, Aug 5, 2014 at 2:36 PM, Bob Stewart b...@evoria.net wrote: I've run into a noise problem on the EFC line of my GPSDO engine at the frequency of the oscillator. I've traced the source down to the 74HCT365 I'm using to output the 1(or 5)MHz and 10MHz signals. When I pull it, the EFC quietens down a lot. I'm seeing about 50mv of 10MHz noise at the output of the op-amp that feeds the EFC voltage divider at the OCXO. The voltage divider is corrected by the VRef from the OCXO with a simple circuit using temp-co'ed resistors. On the 0.1uf cap at the OCXO's EFC pin, I'm seeing about 5mv of 10MHz signal. I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? I'm also wondering what the impact of this level of on-frequency noise will be? Is the impact somewhat mitigated, since it's at oscillator frequency? I don't have anything better than an HP 8558B to look at the output of the board. I'm not quite ready to generally share my schematic with the list, but I can make individual exceptions. Bob - AE6RV ___ time-nuts mailing 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] Effects of noise on EFC line?
For EFC drive, I prefer to use a buffer fed from an analog power, so that the power line noise is not as efficiently inserted into the EFC line. Cheers, Magnus On 08/05/2014 10:00 PM, Chris Albertson wrote: On Tue, Aug 5, 2014 at 11:36 AM, Bob Stewart b...@evoria.net wrote: I've considered switching the HCT out for a 74LS365, assuming my drive levels are compatible. Unfortunately, I don't have one in stock, and I'm way out of my pay grade, as they say. I've also thought about putting a 100uh inductor in series with the EFC line. I wonder if I'll have to isolate the 74xx365 chip's VCC through an inductor? Any thoughts? Not just an inductor but a low pass filter (maybe CLC) designed reject anything outside the bandwidth of your control signal. How often do you update the EFC? Once per second? then your bandwidth is 0.5 Hz. That EFC is very close to DC if your uP is only updating EFC once per second. Your filter should be physically close to the OCXO and have a very large time constant. In addition to this I have a 0.1uF cap soldered directly to the EFC and Ground pins of the OCXO. You say you have detected 10MHz noise, but you can bet there is some 60Hz too. About Vcc, I assume each chip has a bypass that is physically right on the Vcc pin. That is enough. Well almost. You need a digital and an analog power supply, sort of. Don't power both off the same voltage regulator. They can share a transformer But make sure the digital stuff has it's own power rail and it's own voltage reg. Then you do the same with the grounds, digital and analog and tie them together at one place near the power supply. Tuns out these GPSDOs are way-simple now. Just a few parts needed. You can use a serial interface DAC to drive EFC. 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.
