Re: [time-nuts] Dead 5061B

Yes, I've heard of this method before. It may help to study the internal structure of the filament and its support, and orient the tube to get some gravity assistance while trying the procedure. I recall that someone here put up a nice pictorial of the innards of a shot, dissected Cs beam tube

[time-nuts] Dead 5061B

Time Nuts- Thanks to John, Corby, Skip and anyone else I missed who offered help. John got it in one. The hot wire ionizer is open, as measured at the D connector coming out of the tube. I understand that this is a terminal condition. Too bad for me. BTW, I found this note on

Re: [time-nuts] A simple sampling DMTD

Merely selecting every 100th sample throws away the opportunity to reduce the effective ADC noise by digital filtering before decimation. Bruce > On 05 November 2019 at 10:08 Jan-Derk Bakker wrote: > > > Dear Scott, > > You are entirely correct, sampling at 100ksps is mathematically the same

Re: [time-nuts] A simple sampling DMTD

JD, Thanks for your cogent reply. I appreciate it. Best Scott Sent from my iPhone > On Nov 4, 2019, at 5:03 PM, Jan-Derk Bakker wrote: > > Dear Scott, > > You are entirely correct, sampling at 100ksps is mathematically the same as > sampling at 10Msps and then decimating by a factor of

Re: [time-nuts] A simple sampling DMTD

Dear Tobias, Yeah, this thread has been going since late August. As far as I can tell the best way to get it all in one go is at https://www.mail-archive.com/time-nuts@lists.febo.com/msg04265.html ; the main design considerations are listed in the first post. As for the offset oscillator,I have

Re: [time-nuts] A simple sampling DMTD

Dear Scott, You are entirely correct, sampling at 100ksps is mathematically the same as sampling at 10Msps and then decimating by a factor of 100. The reason I'm doing it in this way is driven by two practical considerations: - my ADC, the LTC2140 (selected for bandwidth, dynamic range, aperture

Re: [time-nuts] can of worms: time-of-day in a community radio station

Each NTP Pool server's real-time status can be seen at https://www.ntppool.org/scores/*ip_address* I can't answer questions about the monitor's source code NTP server timestamp errors happen occasionally. Internet delays and losses are unpredictable. My

Re: [time-nuts] Question for my new GPSDO

>> I would advice against using a CMOS switch. They are relatively slow and >> their timing is not well defined. > There are many variants of these tailored to different applications. > You will need to check some more characteristics like charge injection > if you go that route. I also don't

Re: [time-nuts] FE-5440A cesium clock help

I think that the problem is at the modulation or discrimination circuit. When the loop is open, at the mass spectrometer amplifier, i have the modulation frequency (83Hz) and his second harmonic. The 83Hz component level is about 25db over the noise level when system is de-tuned and disappears in

Re: [time-nuts] Raspberry Pi TCXO Hat

Richard Laager writes: > How would it work to have two crystals connected in parallel? Not two crystals in parallel, a crystal plus the output of an (external) reference oscillator. If the two frequencies are close enough you can injection lock the crystal oscillator, but the more likely outcome

Re: [time-nuts] Question for my new GPSDO

Sali Attila, I collect the responses to your last 3 emails in this one. > Summa sumarum: if you can, use low leakage film capacitors, if not use > ceramic. Microphonics can be mitigated a bit by using ceramic capcitors > with high rated voltage. But don't expect magic from that. Thank you for

Re: [time-nuts] can of worms: time-of-day in a community radio station

Hi Since “rogue” servers are rare, bumping up the number of servers fairly quickly gets you to a very high degree of confidence. Is that 5, 7, 9, or 11? It sounds like a wonderful topic for somebody’s thesis or dissertation :) Given that this is a free resource and that the network usage is

Re: [time-nuts] can of worms: time-of-day in a community radio station

att...@kinali.ch said: > This is a pretty baseless fear. The servers in the ntp pool are constantly > monitored and those that are off by more than 100ms are quickly removed > (within 2-3 hours, IIRC). Of course, if you are already using one of those, > then the removal will not help you. But

Re: [time-nuts] A simple sampling DMTD

Hi Jan-Derk this is maybe a bit offtopic, but if you don't mind I would like to ask anyway: is this a DMTD system you have built yourself? I saw a lot of messages on this topic in the archive, but didn't find where it started. Since I would also like to do some clock stability measurements but

Re: [time-nuts] A simple sampling DMTD

Hello, (It has been a more few years since I designed / developed DSP for spectrum analyzers for a major company, thanks for your patience.) I recall that: sample @ fs -> decimate (toss samples) by a factor of N is equivalent to sample @ fs / N If we wanted a lower sample

Re: [time-nuts] Dead 5061B

I would look at ionizer and Ionizer circuit. In the past I would see ion current increase when ionizer turned on. Bert Kehren In a message dated 11/3/2019 11:40:03 PM Eastern Standard Time, paulsw...@gmail.com writes: Jim Is there any hope. I would believe so. CS tubes are pretty tough. As

Re: [time-nuts] A simple sampling DMTD

Dear Bob, I understand the general concern: perfect synchronization would potentially turn the Dual Mixer Time Difference system into a Single Mixer Time Difference setup. (Even with perfect synchronization, the dual-channel architecture would serve to attenuate the common mode component of the

Re: [time-nuts] help understanding drift in two ptpd-synchronized systems

> Similarly, ‘drift’ seems to be the long term averaged (and scaled) offset. Offset without a qualifier usually means time offset. (At least where I hang out.) Drift is frequency offset rather than time offset. It is usually expressed as a (tiny) fraction rather than directly in Hz,

Re: [time-nuts] Raspberry Pi TCXO Hat

> The graph in ntpviz shows the jitter and temp almost perfectly correlated. I'd expect drift to be tracking temperature much better than jitter. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To

Re: [time-nuts] Dead 5061B

I had a 5061A that had those symptoms. It had been running in Cs off mode for a long time and the Ion Pump current looked like zero on casual inspection but was actually barely perceptibly just off the zero mark. I took that to mean that the ion pump had kept the vacuum in the tube very well. The

Re: [time-nuts] Dead 5061B

> This 5061B was working fine until a recent power failure, after which the unit > would not come on line (alarm light stayed lit). > > Major symptoms now... Have you checked the continuity of the hot-wire ionizer? It may have opened up like a light bulb filament when the power came back on.

Re: [time-nuts] Raspberry Pi TCXO Hat

On 11/2/19 1:15 AM, Hal Murray wrote: > > rlaa...@wiktel.com said: >> I'm curious if this would provide any meaningful improvement in system clock >> accuracy, for NTP, if I'm already a GPS PPS hat. If there's a reasonable >> chance this could be interesting, I'm thinking about ordering a couple

Re: [time-nuts] help understanding drift in two ptpd-synchronized systems

Hi Andrew, On 2019-11-03 23:28, Andrew Kohlsmith (mailing lists account) wrote: > Good afternoon, everyone, > > 000702615.150663173 (000342239): state=slave: offset= -107ns > drift=1073.417ppm HCLK=216.232MHz (4.325x) > 000702616.150761324 (000343239): state=slave: offset= -41ns >