Re: [time-nuts] Meinberg (Rode & Schwartz), ED170MP GPS Receiver

Time wrote: > Does anyone have any information for the Meinberg (Rode & Schwartz), ED170MP > GPS Receiver? If you send email to techsupp...@meinberg.de then I'm sure my colleagues of the support group can help. It would be good if you specify a little bit more detailed which information you're int

Re: [time-nuts] Help improving impedance measurement by having a better clock

On Sat, 7 Apr 2018 22:54:42 -0300 Daniel Mendes wrote: > I´m a long time time-nuts lurker (I posted here just a dozen times). I make > a few impedance measurement systems for material analysis (i´m a single man > shop doing custom hardware for clients). Usually they´re based around a > STM32F4 /

[time-nuts] NEO-7 GPS default 1pps width?

I've got some NEO-7Ms here, and without an oscilloscope handy - what's the factory default 1pps pulse width? The manual says pulseLenRatio is zero and pulseLenRatioLock is 100,000 (us) flags-lockedOtherSet is 1, so I think that means "only generate 100ms pulses when locked" Does that align w

[time-nuts] Tbolt temperature sensitivity.

I don't use what LH says about temperature. I compare the 10 MHz output to something else. With two Tbolts sitting about 2 feet apart on my bench, both fed from the same antenna, both with factory settings, when the heat kicks on, I see a change in the difference between the two. Comparing a Tbolt

Re: [time-nuts] Tbolt temperature sensitivity.

Hi Back a while, I ran a fleet of TBolt’s and other GPSDO’s for quite a while. They all ran into HP counters to monitor the PPS outputs. I never saw any of them hit or slip at the 100 ns level. Indeed different GPSDO firmware does the time / frequency tradeoff differently. I’ve also run them ag

Re: [time-nuts] Weird Stuff WareHouse shutting down

Thanks It has to have been Apex that I visited. The back areas were a mix of open sky and sort of sheds. The air was typically pretty dry so the stuff held up well. There were things I would have liked to have grabbed. Could easily see a day digging around. Inside its stacked to the 20 ft ceilings

Re: [time-nuts] Weird Stuff Warehouse shutting down

other surplus: https://www.google.com/search?client=firefox-b-1&tbm=lcl&ei=qGDJWrDzBuXm5gKB3bmQDw&q=electronic+surplus+bay+area+ca&oq=electronic+surplus+bay+area+ca&gs_l=psy-ab.12...16142.25972.0.28698.14.12.2.0.0.0.228.1752.0j11j1.12.00...1c.1.64.psy-ab..0.0.00.qHdPqOyu4I8#rlfi=hd:;si:;mv

Re: [time-nuts] Meinberg (Rode & Schwartz), ED170MP GPS Receiver

I think you can use the GPSMON32 with the ED170 I have an ED167MP, it works only with its downconverter antenna and the rear panel has 2 serial ports and a network connection (a Lantronix serial_port/telnet adapter, a sim

Re: [time-nuts] Weird Stuff WareHouse shutting down

On 4/8/18 7:36 AM, paul swed wrote: Thanks It has to have been Apex that I visited. The back areas were a mix of open sky and sort of sheds. Don't want to be there in an earthquake. After the Northridge quake, they had to rearrange their outdoor maze to improve safety somewhat. The air wa

Re: [time-nuts] Weird Stuff Warehouse shutting down

For those of us (like me) that can travel to the US less than once in a lifetime, there is an EEVblog #124 - A Tour of Apex Electronics: On Sun, Apr 8, 2018 at 2:25 AM, Alexander Pummer wrote: > other surplus: > https://www.google.com/search?client=firefox-b-1&tbm

Re: [time-nuts] NEO-7 GPS default 1pps width?

I have 6M and 8M and they are both 100ms 1PPS signals. Interpolate. > Le 8 avr. 2018 à 15:51, jimlux a écrit : > > I've got some NEO-7Ms here, and without an oscilloscope handy - what's the > factory default 1pps pulse width? > > The manual says pulseLenRatio is zero and pulseLenRatioLock is

Re: [time-nuts] NEO-7 GPS default 1pps width?

Yes, that's exactly how Ublox default PPS setting works. Pulse is positive - rising edge is "the time." Leo On 8 Apr 2018, at 17:00, time-nuts-requ...@febo.com wrote: > The manual says pulseLenRatio is zero and pulseLenRatioLock is 100,000 (us) > flags-lockedOtherSet is 1, so I think that means "

Re: [time-nuts] Cheap jitter measurements

>>> What do you mean by "jitter" and what do you really want to do? >> I mean jitter as NTP defines jitter. Whatever that is. > > I think you need to figure out what you want to do so you don't fool yourself. > > ntpd is a PLL. There is a low pass filter in the control loop. It will > track t

Re: [time-nuts] Weird Stuff WareHouse shutting down

> Thanks > It has to have been Apex that I visited. The back areas were a mix of open > sky and sort of sheds. > The air was typically pretty dry so the stuff held up well. I did see some populated circuit boards absolutely caked with dirt (was probably dust at first). Maybe not just outside, eithe

Re: [time-nuts] Cheap jitter measurements

Hi Ok, I’ll bite …. > On Apr 8, 2018, at 3:36 PM, Tom Van Baak wrote: > What do you mean by "jitter" and what do you really want to do? >>> I mean jitter as NTP defines jitter. Whatever that is. >> >> I think you need to figure out what you want to do so you don't fool >> yourself. >>

Re: [time-nuts] Weird Stuff WareHouse shutting down

C&H was SUPERB for test equipment in the 1990's when the aviation industry in Southern California was downsizing. IMHO not nearly so interesting today. Unless you're into pneumatics in which case they are a delight. Tim N3QE On Sun, Apr 8, 2018 at 10:36 AM, paul swed wrote: > Thanks > It has t

Re: [time-nuts] Help improving impedance measurement by having a better clock

Hi Daniel: If you're concerned with accuracy of impedance measurements you might want to spent a lot of time studying "The Impedance Measurement Handbook", it's the bible for this.  The way the measurement is made has a huge impact on the accuracy.  For example using a vector network analyzer t

Re: [time-nuts] Help improving impedance measurement by having a better clock

Hi I believe we are talking about material impedances here rather than electrical impedance. One of the weird things about this is that frequency (as in frequency accuracy) *can* be a contributor to the resultant error. Thus my original question about just what the concern actually is….. Bob

Re: [time-nuts] Cheap jitter measurements

>> Similarly, the box should be able to give me a pulse at a known time. > > how do you set up NTP to do that? Don't know. That's not NTP's job. Any process that can query system time and get/set a GPIO bit will do. The question to be answered is how close to the real time (as in UTC(k), atomic

Re: [time-nuts] Weird Stuff Warehouse shutting down

Really appreciate the video of Apex. I don't think words describe it very well. But everything is there and whats more interesting is if you are looking for something they do have a pretty good idea of the location. Especially if it has any value like new BNC connectors. The time I went there I was

Re: [time-nuts] Cheap jitter measurements

I want to jump on Tom's post, and Bob's note at 1:14 on Saturday (that begins with "Just to be very clear..." They both raise an important point about measurements. With both NTP and GPSDO measurements a lot of folks focus heavily on what the "black box" is reporting about itself. But self-c

Re: [time-nuts] Cheap jitter measurements

kb...@n1k.org said: > In both cases (pulse in and pulse out) the first step is to ask NTP “when > was that?”. You still have a pretty big chunk of NTP in the middle of the > process …. If NTP only “knows” what is happening (or can control what is > happening) to +/- 300 ns. The guts of

Re: [time-nuts] Cheap jitter measurements

Tom Van Baak wrote on Sun, 8 Apr 2018 at 12:36:52 -0700 in <55EB8D26CCDC4B1ABFBC53F95E4C0557@pc52>: > My mental model of a black box computer running NTP ... > Imagine the black box has two BNC connectors; one accepts an input > pulse to be timed; one outputs a pulse at certain times. Theory ru

Re: [time-nuts] Cheap jitter measurements

Pity the poor man who has (n>1) clocks, for he knows not what time it is. Dana On Sun, Apr 8, 2018 at 4:29 PM, John Ackermann N8UR wrote: > I want to jump on Tom's post, and Bob's note at 1:14 on Saturday (that > begins with "Just to be very clear..." They both raise an important point > abou

Re: [time-nuts] Weird Stuff WareHouse shutting down

On 9/04/2018, at 3:52 AM, jimlux wrote: > Test equipment tends to be aged - Unless you have a particular need for a HP > 600 series microwave signal generator, there are probably better sources > available much cheaper that use more modern components. In this day and age, > I don't think peopl

Re: [time-nuts] Cheap jitter measurements

Hi Without the ability to put out a “known good” time pulse there is no quick way to check NTP. GPS modules suffer a similar issue. They put out a pulse and a “correction” (sawtooth error) to tell you what they just told you. Doing the same sort of thing with NTP may be possible. Indeed the

Re: [time-nuts] TS2100 OCXO Conversion: Command exploration

And, as of today, I still can't get it to lock. :-P I think I'm going to have to conclude, reluctantly, that the full-size OCXO's are simply not compatible with this unit. It strikes me as possible there may be other hardware changes needed to run such. It's just impossible to tell

Re: [time-nuts] Weird Stuff WareHouse shutting down

On 8 Apr 2018 16:56, "jimlux" wrote: > > Test equipment tends to be aged - Unless you have a particular need for a HP 600 series microwave signal generator, there are probably better sources available much cheaper that use more modern components. In this day and age, I don't think people should s

Re: [time-nuts] Cheap jitter measurements

That may be an article of faith for those who haven't experienced the delights of time-nuttery, but to be fair, the man with n<2 clocks doesn't know what time it is either. Even if n=1, he only believes he knows what time it is. I appreciate that the clock-blessed may have doubts about the truth o

[time-nuts] ADEV dead time w/ HP 53131A & TimeLab

Hi time-nuts, I'm doing oscillator-related research for my PhD and found this list recently. It's been a great resource in trying to refine my freq measurement setup and in starting to understand what's really going on inside my lab equipment. I've been trawling the archives and have a question a

Re: [time-nuts] Cheap jitter measurements

" I appreciate that the clock-blessed may have doubts about the truth of his sources. But the fact is, you need a larger sample size to better estimate error. The man who is happy in his ignorance has not considered that calibrated doubt can be more satisfying than unjustified certainty." -

Re: [time-nuts] ADEV dead time w/ HP 53131A & TimeLab

Hi The basic fact is that oscillators drift on *all* time scales. How much they drift depends on the type of oscillator. A free running VCO based on a PCB resonator will drift differently than a bare crystal oscillator. An OCXO will have different drift characteristics than a bare oscillator.

Re: [time-nuts] Weird Stuff WareHouse shutting down

The USB stuff has no front end and stability and calibration is highly questionable.. How can you discriminate between mixes within the USB device and the signal of interest? I will take my 141T or my 8566 over USB every time. Rather lug a little weight around and know what I am seeing on the d

Re: [time-nuts] Weird Stuff WareHouse shutting down

drkir...@kirkbymicrowave.co.uk said: > I think people learn more with old test equipment. I know someone who has a > 1 GHz LeCroy scope, as well as a high end Agilent, but can't seem to > measure the simplest of signals, that I could easily measure with a 50 year > old scope. With modern scope