Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

On Sat, 2 Jul 2016 19:00:24 +0200, you wrote: >On Fri, 1 Jul 2016 12:28:44 -0400 >Bob Camp wrote: > >> Real cascode circuits can be built with RF transistors. They also can be >> simulated. >> Simulating them with the “standard” models is a PIA. The issue is that the >>

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

>Why do people use general purpose transistors in these places, even >though RF transistors definitly improve switching behaviour? Commercial designs do use RF transistors but only old ones are documented. The Tektronix 7A11 uses 2 GHz PNPs and 1 GHz NPNs but its design is unusual since it can

Re: [time-nuts] Sub-ps delay line

I did something similar a couple years ago to make an adjustable 75 nanosecond pretrigger for my sampling oscilloscope so I will just pass along some things I learned. Power supply noise will create jitter in single ended logic because of lack of power supply rejection. Temperature will be a

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

On Sat, 28 Jan 2017 13:58:27 +0200, you wrote: >... > >The picture gallery also shows a pulse distribution amp for 1PPS. It has an >LT1711 comparator feeding an 74AC14 buffer with length-matched traces to >74AC04's at the outputs. So far my length-matching didn't give zero >output-skew between

Re: [time-nuts] Line Frequency standard change - Possible ?

On Thu, 9 Feb 2017 19:06:51 -0500, you wrote: >One simplistic way to look at all this is that a switcher presents a “negative >resistance” load. If you drop voltage, current goes up. OCXO’s happen >to share this issue. Negative resistances are *not* what most power source >guys want in their

Re: [time-nuts] Line Frequency standard change - Possible ?

On Thu, 09 Feb 2017 23:39:24 +, you wrote: >It is harder than it sounds. > >Small solar inverters are the best, they an regulate down at milliseconds >notice, and many jurisdictions impose asymetric frequency bands on >them to exploit this. > >Big inverters, no matter what you put behind

Re: [time-nuts] Line Frequency standard change - Possible ?

On Thu, 9 Feb 2017 17:19:49 -0500, you wrote: >Isn't this "hard" lock to UTC creating a single point of failure? A >solar burst, an EMP, or >a software error could leave us all in the dark. After all, smart >inverters could be >programmed to act like big lumps of rotating iron and be

Re: [time-nuts] ``direct'' RS-232 vs. RS-232 via USB vs. PPS decoding cards

On Tue, 14 Feb 2017 10:31:30 -0500, you wrote: >On 14/02/2017 7:26 AM, Bob Camp wrote: > >> A direct port might be a +/- 100 ns sort of thing most of the time and a >> +/-10 us >> thing every so often under some OS’s. Most desktop operating systems are not >> designed to prioritize random pin

Re: [time-nuts] 10MHz to 25MHz

This document covers various methods but I agree with Rick about phase locking a separate crystal oscillator; harmonic frequency multiplication is more useful at higher frequencies where other methods are unavailable: http://www.qsl.net/va3iul/Frequency_Multipliers/Frequency_Multipliers.pdf An

Re: [time-nuts] wifi with time sync

Modern systems are very aggressive about DVFS (dynamic voltage and frequency scaling) so it would not surprise me at all. I have run across this problem on the timescale of one second even on 10 year old desktop hardware. On Sun, 15 Jan 2017 09:32:56 -0500, you wrote: >Hi > >I’d be surprised if

Re: [time-nuts] wifi with time sync

Sonos and I guess their competitors do this by dropping WiFi compatibility. They exist on their own network in the same ISM band so I wonder how well they coexist with WiFi. Online reports say poorly under crowded band conditions. On Sun, 15 Jan 2017 09:50:05 -0500, you wrote: >Hi > >The push

Re: [time-nuts] 10MHz to 25MHz

On Thu, 19 Jan 2017 10:48:57 -0800, you wrote: >On 1/19/2017 5:40 AM, David wrote: > >> oscillator. In some applications I would also be concerned about the >> phase of a narrow bandpass filter changing with temperature. > >The 5061 has tuned bandpass filter multip

Re: [time-nuts] 10MHz to 25MHz

On Wed, 18 Jan 2017 21:06:04 -0800, you wrote: >On 1/18/2017 6:34 PM, David wrote: > >> An alternative very simple design I might try is a variation of the >> active frequency multiplier where the 5th harmonic is filtered >> directly from the output of the digital divide

Re: [time-nuts] ADC sample voting algorithm?

I always try to calculate things like the standard deviation and peak-to-peak to get some idea if the measurement is valid. A DSO with infinite persistence or envelope mode is great for tracking this sort of thing down during development. Only toy DSOs will lack both. On Wed, 05 Oct 2016

Re: [time-nuts] Why are PPS pulses so narrow? (was: 53132A triggering)

I would not use such a narrow pulse for any of those reasons except for power if that was an issue. I would and have however used narrow pulses simply because it allows for a lower volt*time product on a transformer. On Fri, 16 Sep 2016 21:03:12 -0400, you wrote: >Hi > >It is sort of an "

Re: [time-nuts] 53132A triggering

The new ones don't? That would be annoying. My old Racal-Dana 1992 remembers when in standby mode but not if it loses power. On Fri, 16 Sep 2016 15:21:50 -0400, you wrote: >Thanks, Bob. I just tried that and got solid results. One nice thing about >the 5370 vs this newer stuff is that the

Re: [time-nuts] HP-105B Battery Replacement?

I have a pair of Liebert GTX2-700RT online UPSes and they work well; I just replaced the batteries, lubricated the fans, and cleaned the dust out of them a couple weeks ago. They have that sort of standard 4 prong socket on the back for external batteries. But unlike my two Powerware Prestige

Re: [time-nuts] HP-105B Battery Replacement?

High end standby UPSes support external batteries but most or all online UPSes do. I have 3 different online UPS models and they all support external batteries of either 48 or 60 volts. On Thu, 15 Sep 2016 15:13:59 -0700, you wrote: >Since I have a 12V 100 A-H gelled electrolyte battery as a

Re: [time-nuts] Thunderbolt spurs on 10MHz output at 100Hz and 200Hz from signal.

Worn out aluminum electrolytic capacitors usually improve in performance lowering ripple and noise as they warm up. On Sun, 18 Sep 2016 12:27:38 +0100, you wrote: >Now that's interesting I just re-ran the measurement, and got a quite >different result which is attached. The spurs have GONE. >

Re: [time-nuts] Optical link connects atomic clocks over 1400 km of fibre

I could not find it in the links but Magnus mentions 50 Hz instead of 100 Hz. I would expect a 100 Hz noise signal if it was vibration coupled from magnetostriction in a transformer; magnetostrictive strain depends on the magnitude of the magnetic field strength and not the sign which is why

Re: [time-nuts] DIY VNA design [VNA-Nuts?]

On Mon, 22 Aug 2016 23:44:17 +0200, you wrote: >On Mon, 22 Aug 2016 14:20:59 -0400 >Bob Bownes wrote: > >> Just finished creating it at groups.io >> >> *https://groups.io/g/svna * >> and sign up. :) > >Is there any advantage of using groups.io compared

Re: [time-nuts] A new take on the all-hardware GPSDO concept

Is there a schematic showing what you attempted? I went back through the discussion thread and it was not real clear to me which design you implemented. On Mon, 26 Sep 2016 21:18:25 -0700, you wrote: >... > >The results aren’t very good. > >With a short TC loop filter, the PLL does lock up, but

Re: [time-nuts] Caroliine .. I need to move on

I was thinking message from Cave Johnson. On Sat, 1 Oct 2016 23:24:09 -0700, you wrote: >Hurricane I believe > >-=Bryan=- > >> From: jim77...@gmail.com >> >> Well I'm intrigued! >> >> On 2 October 2016 at 15:53, Ian Stirling wrote: >> >> > going to the emergency place

Re: [time-nuts] Temp/Humidity control systems?

Years ago I had to deal with this and the instruments and sensors we used matched well against dry and wet bulb measurements. I suspect consumer level stuff varies considerably in reliability and accuracy. The capacitive sensors are tricky to use because they require AC excitation to prevent

Re: [time-nuts] I love the smell of tantalum in the morning

I usually find that the pad itself has enough tin plating to melt and adhere the part's termination so I tack it down like that, solder the second termination, and then go back and solder the first termination. On Mon, 7 Nov 2016 02:34:51 +, you wrote: >The best way to hand solder small SMT

Re: [time-nuts] Man with too many clocks.

My simple solution to this was to divide the 1 PPS signal down so the jitter from the uncorrected GPS was a smaller part. Of course then each measurement takes proportionally longer. On Fri, 4 Nov 2016 11:35:59 -0400, you wrote: >I gave up on trying to use the GPS 1 PPS signal to calibrate the

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, 4 Nov 2016 18:23:16 -0400, you wrote: >I no longer have DISH but I did have it a year ago and the outage >happened every year like clockwork , they even sent me a notice that I >could expect a sun outage and I did.. I also experienced outages every >time a thunderhead at 30,+ feet

Re: [time-nuts] Thinking outside the box a super reference

On Fri, 04 Nov 2016 14:39:54 -0700, you wrote: >On Fri, Nov 4, 2016, at 02:27 PM, Poul-Henning Kamp wrote: >> >> In message <2af27ebe-9200-c348-c89b-b98f9c973...@karlquist.com>, "Richard >> (Rick) Karlquist" w >> rites: >> >Also, one of the Rb isotopes is slightly radioactive. >> >35

Re: [time-nuts] Satellite TV messed up, how is GPS time

On Fri, 4 Nov 2016 18:43:03 -0400, you wrote: >... > > There HAVE been attempts to deliberately jam cable distribution >satellites... mostly the EIRPs used for distribution signal uplinks >make this a bit difficult, but it has been done. There are also some >countermeasures in place to

Re: [time-nuts] I love the smell of tantalum in the morning

On Sat, 5 Nov 2016 20:57:11 +0100, you wrote: >> Having not done SMT before, how should I do it with minimal risk to the very >> precious PCB. Or, what equipment should I use this as a good excuse to buy? > >Now, for these caps, you can use a normal soldering-iron without too >much trouble, but

Re: [time-nuts] 1PPS to 32.768 khz

On Tue, 18 Oct 2016 22:59:42 -0700, you wrote: >> 1. Does anyone know of a device that will take a 1PPS GPS timing signal and >> generate a 32.768 kHz sine wave output ? I have big digital clock that uses >> an 8 bit micro processor and an external 32.768 crystal. Obviously the >> external

Re: [time-nuts] measuring noise of power supplies (was: For those that insist on using switching power supplies)

On Tue, 18 Oct 2016 11:27:05 +0200, you wrote: >On Fri, 14 Oct 2016 22:25:55 -0500 >David <davidwh...@gmail.com> wrote: > >> I have done this and it works great; the breakpoint between the >> chopper amplifier and the low noise amplifier can be adjusted to >>

Re: [time-nuts] 1PPS to 32.768 khz

I was thinking 32.768kHz VCXO and phase detector to make a simple analog PLL. I found a datasheet for a suitable VCXO and assuming a total error of 20ppm, it would only need to be divided by 2 to prevent locking to the wrong frequency making an analog PLL pretty simple. Safer to divide by 4 or 16

Re: [time-nuts] measuring noise of power supplies (was: For those that insist on using switching power supplies)

I have done this and it works great; the breakpoint between the chopper amplifier and the low noise amplifier can be adjusted to combine the wideband noise from the low noise amplifier and the 1/f noise and drift of the chopper amplifier. Jim Williams wrote a couple of different application notes

Re: [time-nuts] measuring noise of power supplies

On Tue, 18 Oct 2016 14:52:15 +0200, you wrote: >Hoi David, > >On Tue, 18 Oct 2016 05:25:35 -0500 >David <davidwh...@gmail.com> wrote: > >... > >> thermal EMF becomes a large if not the largest contributor. > >Ah.. good to know. Thanks! >Any guess what th

Re: [time-nuts] Anybody want a Thunderbolt power supply?

On Fri, 21 Oct 2016 10:59:59 +0200, you wrote: >On Fri, 21 Oct 2016 00:20:43 -0400 >Scott Stobbe wrote: > >> The bad side of a 7912 is in long-term stability and tempCo, the sample I >> tested had at least a 150 ppm/degC tempCo, which is going to put a serious >>

Re: [time-nuts] How can I measure GPS Antenna quality?

When I was doing VHF and UHF direction finding antenna design, I would drive out to the highest readily accessible hilltop for testing. Once I came up with a low sidelobe design, I started picking up things like lamp posts, trees, and bushes in the parking lot, aircraft over LAX and John Wayne

Re: [time-nuts] New Timestamping / Time Interval Counter: the TICC

John, In what language is the GUI written? I might be able to help on that, or other parts of the software, if someone else hasn't yet volunteered. Dave, WA8YWQ On 2016-11-24 06:43, John Ackermann N8UR wrote: > Hi Anders -- > > Thanks, and thanks for the info on the 53230A. I have not

Re: [time-nuts] precision timing pulse

On Wed, 16 Nov 2016 11:14:59 -0800, you wrote: >albertson.ch...@gmail.com said: >> I'm wondering why everyone seems to be assuming a PIC is the right processor > >If you want cycle-accurate timing, one approach is to count cycles. If you >have an assembly level background, the PIC is as good as

Re: [time-nuts] Thermal impact on OCXO

I have only heard of and never observed the problem of manufacturers cutting the middle out of a gaussian distribution for tighter tolerance parts. Robert Pease of National Semiconductor had an even better story: I recollect the story of one of the pioneering transistor companies, back in the

Re: [time-nuts] our favorite topics

That is always the danger when using parts for characteristics not guaranteed in the specifications. Sometimes a process just becomes obsolete necessitation new parts to be fabricated on a new process. Or a process may have enough variation that some lots or parts meet unguaranteed

Re: [time-nuts] our favorite topics

You mentioned suitable transistor availablity being an increasing problem and I have run across that myself. Do you expect Qualcomm's aquisition of NXP to have an impact? NXP is currently the best source I have for fast complementary pairs or even just fast PNPs. On Sun, 30 Oct 2016 16:06:19

Re: [time-nuts] Opening an Isotemp OCXO

I do not think the designer was considering noise at all because tying the inputs together would not do anything useful. Emitter resistance is inversely proportional to emitter current (26/mA) but putting them in parallel lowers the current through each emitter so the total emitter resistance

Re: [time-nuts] What would be the proper equipment and procedure?

But I got my question answered anyway. :) On Sat, 29 Oct 2016 05:29:26 +, you wrote: >Yep, should have gone to volt-nuts. Recent changes Microsoft has been doing >to Outlook, etc have been causing all sorts of fun gltches. One being not >actually taking copy-pastes of addresses and/or

Re: [time-nuts] For those that insist on using switching power supplies

Even if they meet the CE or FCC requirements for unintentional radiators, they can still screw up the short wave bands and more; many are bad enough that I can see the noise they emit on an oscilloscope with a shorted probe. At least in the US, there are a *lot* of cheap products with switching

Re: [time-nuts] Totally unrelated, but..

On Thu, 8 Dec 2016 02:25:14 +0100, you wrote: >Am 08.12.2016 um 01:20 schrieb Scott Stobbe: >> Yes, the short hand I like to use is 4 nV*sqrt(R/1000). >> >> 2 nV/rthz off a bandgap is pretty darn impressive, that includes a delta >> vbe gained up ~10x. > >Methinks the advantage comes from

Re: [time-nuts] Totally unrelated, but..

I am pretty sure that I ran across this once as well with the 7800/LM340 series in the early 1980s with parts from a major manufacturer like Motorola, National, or Texas Instruments; the regulators ran hot and the output voltages were slightly low no matter what decoupling arrangements were made

Re: [time-nuts] Measuring sidereal/solar time? Re: A Leap Second is coming

To improve the accuracy, I would integrate several measurements. There is no reason a sampled measurement at only one time needs to be made. On Fri, 30 Dec 2016 09:18:17 -0800, you wrote: >Hi Anders: > >That's something I've thought about for decades using an optical system. A >few years ago

Re: [time-nuts] WWVB Simulator

Not all PC audio hardware includes such a low high frequency cutoff. http://www.clarisonus.com/Research%20Reports/RR001-SoundCardEval/RR001-PCsoundCards.html Based on the above review, the following cards which are still available have a response that extends significantly above 60kHz:

Re: [time-nuts] WWVB Simulator

I see generally how it should work but did not draw out a truth table. Why use the 74CB3T3253 instead of a low voltage 4052 variant? It think you could buffer just the two references and save two operational amplifiers and 2 or 4 capacitors. On Mon, 2 Jan 2017 21:18:12 + (UTC), you wrote:

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

On Wed, 21 Dec 2016 19:29:00 +, you wrote: > Can anyone comment on the following data, and whether they think the > oscillator in "my" M8N is a XO or a TCXO ? > >Can you monitor the current draw from cold (ambient)? > >You may be able to identify the initial steady current drawn by

Re: [time-nuts] Problem with HP 83623A 20 GHz sweep generator stepping up/down 100 Hz when not wanted.

On Thu, 22 Dec 2016 12:39:27 +, you wrote: >But I find it a bit odd that HP would have a 1 Hz software option on this >instrument, if the instrument jumped up/down 100 Hz. > >Now I don't yet have the 1 Hz option programmed in, and it might well >change the behavior completely, but I'd still

Re: [time-nuts] Single ended or differential input to TDC chip

On Mon, 27 Mar 2017 18:05:13 +0200, you wrote: >... > >* Single-ended input in a chip might lead to shifting ground potential > on the chip and thus to measurment jitter. > >... This is a major problem I have run across before. Various single ended logic families have great noise immunity as

Re: [time-nuts] Antique precision timing device without electronics

I think Bob Pease of National Semiconductor fame mentioned looking for the earliest use of phase locked loops and finding a reference to a European clock maker who had a master pendulum clock with a mechanical coupling that phase locked newly built clocks when left connected overnight. On Thu, 16

Re: [time-nuts] TAPR TICC boxed (input protection)

Low current measurements take a lot of time on the automatic test equipment and time in this case is measured in seconds. The same applies to low frequency noise. For an example, take a look at the National (now TI) LMC6001 and LMC6081: https://goo.gl/LCY2vR Unlike National, TI does not care

Re: [time-nuts] TAPR TICC boxed (input protection)

On Wed, 5 Apr 2017 09:13:34 +1200 (NZST), you wrote: >A protection diode needs to also have a fast turn on with little or no >overshoot of the forward voltage. That would be ideal but forward turn on time is rarely specified and usually assumed to be fast and some fast diodes have appallingly

Re: [time-nuts] TAPR TICC boxed (input protection)

magnitude.  Considering that our electrometers had an input >impedance of 1E-12 to 10E-15, even a fingerprint made a huge difference.  The >carbon filled black paint was practically a short. >Maybe an overcoat with silicone or some other type of low leakage sealant, >then the black pai

Re: [time-nuts] TAPR TICC boxed (input protection)

On Sat, 8 Apr 2017 16:30:38 -0400, you wrote: >David wrote: > >> I mentioned this in connection with some manufacturers using gold >> doping in transistors which would not normally be expected to have >> gold doping. So you end up with a bunch of lessor named 2N3904s

Re: [time-nuts] TAPR TICC boxed (input protection)

On Sat, 8 Apr 2017 21:43:31 +0200, you wrote: >Am 08.04.2017 um 17:52 schrieb David: >> >> If they are not being tested, then where is the maximum specified >> leakage number coming from? For a small signal bipolar transistor it >> will typically be 25nA, 50nA,

Re: [time-nuts] TAPR TICC boxed (input protection)

They are relevant when a high input impedance buffer is used making it easier to add series/shunt overload protection. Protecting against 400 volts and higher is feasible this way. Adding overload protection to a 50 ohm input is an interesting challenge but it can be done. Precede the 50 ohm

Re: [time-nuts] Line Frequeny Stablity

I have seen some proposals to require VAR capability in photoelectric installations but how feasible is that? I cannot imagine utility customers being pleased with having to pay extra for such a nebulous to them capability. I could see the utility companies pushing it as a requirement in lieu of

Re: [time-nuts] TAPR TICC boxed (input protection)

On Wed, 5 Apr 2017 02:40:13 -0400, you wrote: >David wrote: > >> So collector-base junctions make good low leakage high voltage diodes >> although they are slow > >I guess it depends on what one means by "slow" and "fast." I was referring to within

Re: [time-nuts] Re. DIY atomic "resonator"

Some incandescent lamps can emit RF. http://www.rexophone.com/?p=1081 http://www.radiomuseum.org/forum/rustika_lightbulb_fm_measurements.html On Tue, 11 Apr 2017 18:09:52 +, you wrote: >Apparently fluorescent tubes continuously emit a lot of other microwave >signals. I once built a

Re: [time-nuts] RFDO - Experience and questions

If the modulation is phased locked to the carrier which is common, then that suggests two other ways to extract the timing from the carrier without interference from the modulation. 1. Integrate the phase comparison over a whole number of modulation cycles; the modulation will then cancel out.

Re: [time-nuts] TAPR TICC boxed (input protection)

On Thu, 6 Apr 2017 22:23:43 -0400, you wrote: >David wrote: > >> I know one thing to watch out for if you are looking for low >> leakage is gold doping > >Anything that increases carrier mobility increases leakage current (all >else equal -- i.e., for each

Re: [time-nuts] TAPR TICC boxed (input protection)

On Fri, 7 Apr 2017 01:06:17 -0400, you wrote: >Another thing to watch out for if you need very low leakage, is if the >package is transparent. All junctions are photodiodes. > >Maybe it's less of a problem now with SMTs, than it was with glass body >diodes or translucent transistor packages. >

Re: [time-nuts] TAPR TICC boxed (input protection)

On Fri, 7 Apr 2017 04:09:38 -0400, you wrote: >David wrote: > >>> what doping is used for PNP RF transistors and saturated switches >>> if it is not gold? Does it also increase leakage? > >I replied: > >> Gold doping doesn't affect the speed of BJTs i

Re: [time-nuts] OCXO Soft-Start

On Wed, 12 Apr 2017 20:18:38 -0700, you wrote: >On 4/12/17 7:14 PM, Richard (Rick) Karlquist wrote: >> 10.9 MHz is likely the B-mode of the SC cut. >> (It's a different mode, not a different overtone). >> This mode has a tempco of 20 ppm and is used >> to do thermometry. >> >> IMHO, there is NO

Re: [time-nuts] Frequency counter questions

High end frequency counters usually go to some effort to prevent synchronization between the input signal and the gate. Some DSOs do as well. Synchronization can exasperate certain errors and asynchronous operation provides better results when many measurements are averaged. On Tue, 25 Apr 2017

Re: [time-nuts] Poor man's oven

I have never been able to find a reference to them on the internet but there was a similar product intended for TO-99 packages that could be used with operational amplifiers. On Mon, 5 Jun 2017 08:35:35 + (UTC), you wrote: >  The Crystal heater clip wasa Murata "Posistor" soldered onto a

Re: [time-nuts] Using 5335 frequency counter for timing

My Racal-Dana 1992 is the same way; its time interval mode is limited to the 1 nanosecond interpolated resolution of the counter. Some counters support time interval averaging which will produce much much higher resolution but often they have a minimum time interval. If the transmission line to

[time-nuts] Time stamp degradation being added in javascript

Possibly not of immediate concern to time-nuts but an article had some trigger words for them in the initial fixes to the much publicised problems with Intel/AMD/ARM etc : "After these changes, the time stamp returned by |performance.now| will be less precise due to lower resolution. Some

Re: [time-nuts] Serial port splitter s/w

Serial outputs can usually drive several serial inputs if the cables are short (to avoid reflections). You can wire it yourself, serial out from the TB to both LH and NTP, serial in from LH only. David On 2/26/14 11:51 AM, David J Taylor wrote: I'm running Meinberg NTP on the Windows 7 x64

Re: [time-nuts] A small piece on HP's hydrogen maser in 1968

___ 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] GPSDO module connections

reflections will degrade its risetime. Good luck, David On 3/3/14 1:01 PM, d0ct0r wrote: Hello, I am looking for the advise: what will be the better method to connect GPSDO module by short extension cable to put its antenna input on front or back panel ? Lets say, GPSDO module has female

Re: [time-nuts] ELEMEK LXK WWVB Receiver

From an ad in Radio-Electronics June 1980, it mentions that it phase-locks to the carrier. I expect the new format of WWVB will give it fits. https://archive.org/stream/radio_electronics_1980-06/Radio_Electronics_June_1980#page/n71/mode/2up/search/wwvb 73, David N1HAC On 3/11/14 1:55 PM

Re: [time-nuts] ELEMEK LXK WWVB Receiver

From an ad in Radio-Electronics June 1980, it mentions that it phase-locks to the carrier. I expect the new format of WWVB will give it fits. https://archive.org/stream/radio_electronics_1980-06/Radio_Electronics_June_1980#page/n71/mode/2up/search/wwvb 73, David N1HAC On 3/11/14 1:55 PM

Re: [time-nuts] Equinox and sidereal time

There is a UK version of the almanac: http://asa.hmnao.com/ David N1HAC On 3/24/14 7:26 AM, Tim Shoppa wrote: Try the _Astronomical Almanac_. I am not so familiar with the navigation almanacs, but the bread and butter of the astronomical almanac is the equation of time and transformation

Re: [time-nuts] Equinox and sidereal time

There is a UK version of the almanac: http://asa.hmnao.com/ David N1HAC On 3/24/14 7:26 AM, Tim Shoppa wrote: Try the _Astronomical Almanac_. I am not so familiar with the navigation almanacs, but the bread and butter of the astronomical almanac is the equation of time and transformation

Re: [time-nuts] Airraft Ping Timing

I am surprised it took them this long. A number of satellite telemetry systems can use doppler as a matter of course for locating transmitters, such as Iridium and Argos. David On 3/25/14 12:58 AM, Peter Gottlieb wrote: This is how ELT locating satellites work (when not relaying the newer

Re: [time-nuts] Is this ocxo salvageable?

The output looks differentiated, as would happen if the wire connecting the internal circuit to the output pin became open, leaving only a very small capacitance to couple the square wave out. Dave On 4/8/2014 11:46 PM, Chris Albertson wrote: My Bliley square wave 10MHz OCXO was working just

Re: [time-nuts] NIST Radio Station WWV now on 25 MHz

Yea! I remember when they shut it down at the nadir of the sunspot cycle, saying no one was using it. Duh! David N1HAC On 4/11/14 12:07 AM, Max Robinson wrote: WWV used to be on 25 MHz but when the sunspot cycle hit a minimum they shut it down. That was years ago. I'm glad to know

Re: [time-nuts] NIST Radio Station WWV now on 25 MHz

Easily heard on a 12 ft wire in NH this afternoon. Chuck - You may be too close and it is skipping over. David N1HAC On 4/11/14 8:37 PM, paul swed wrote: Chuck The an/urr R1051 does not have a signal meter. It has level meters for audio. Those navy radios. I guess they figured the radio

[time-nuts] Looking for GPSDO for home use

I found this reflector after searching for GPSDO that would be suitable for individual purchase/use. Each time I found an article about GPSDO projects, that lead me to a surplus GPS module that is either no longer available, not current production, undocumented, or otherwise difficult to

Re: [time-nuts] quartz clock/watch question

I have done that as well. The G-Shocks have a trimmer cap (I have a DW-6900/module 3230). I don't remember the frequency at the adjustment test point but it is something like 100 Hz. David On 4/18/14 7:40 PM, Jim Palfreyman wrote: I've opened up my Casio G-Shock watch, found an electrical

Re: [time-nuts] GPSDO and holdover

Some timing GPS units (eg Oncore UT) can be set to omit 1PPS pulses if no satellites are being tracked, or if the RAIM alarm limit is exceeded. Dave On 4/25/2014 10:20 AM, Paul wrote: On Tue, Apr 22, 2014 at 9:57 PM, Tom Van Baakt...@leapsecond.com wrote: I have noticed skipped 1PPS on the

[time-nuts] Need simple test command to verify connection to UT PLUS module

I have interfaced a Motorola Oncore UT PLUS module to my Linux PC via serial port and RS-232 adapter. When I power up the module I see 1 PPS from the pin (currently connected to a LED via current limiting resistor.) The port is set to 9600 bps 8/N/1 but no messages are being seen (I think this

[time-nuts] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module

I'm trying (in lieu of setting up a GPSDO) to use the 1 PPS output of a Motorola ONCORE UT+ module to do a one-time reference oscillator adjustment of my frequency counter (setting its reference oscillator which has a small trimmer). My counter has a totalize mode where it counts pulses from

Re: [time-nuts] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module (Hal Murray)

I'm using 74HC series for the divider/gate. I appreciate all the troubleshooting help, however, I still don't know under what conditions the 1 PPS output should be relied on (with zero satellites acquired? one? four? all eight?, and what can be expected of the 1 PPS output interval if there

Re: [time-nuts] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module

Picked this project back up this afternoon after couple of weeks, narrowed the problem down but not solved. Refresh: My ONCORE UT+ module appears to have very extreme jitter (on on order of 100 uSec, not nSec random variation between leading edges of successive pulses) in the 1 PPS output. I

Re: [time-nuts] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module

Thank you, Tom - I appreciate the advice. I am using a 74HC390 in the (divide-by-20, square wave output) divider chain, and sure enough, after looking more closely at the data sheet, it clocks on the FALLING edge (I thought otherwise - wrong)! I will stick an inverter in the path and that

Re: [time-nuts] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module

Thanks to Tom, Jean-Louis and Chris for all of the helpful advice. Problem is now fixed. First problem was obvious - the 74HC390 I use as a divider clocks on negative-going transition. Added inverter, and the problem appeared to still be present (!) Next problem was not so obvious - my very

Re: [time-nuts] FE5680 GPS Disciplined Controller

about 4 days to manufacture and they are then shipped by airmail. Have a look at :- http://imall.iteadstudio.com/open-pcb/pcb-prototyping.html David t 04:49 AM 19/06/2014, you wrote: ewkeh...@aol.com David G. Hopkins (VK4ZF) CAPALABA QLD AUSTRALIA 27.32.38S 153.12.03E QG62OL Skype :- davhop

Re: [time-nuts] More FE5680 GPS Disciplined Controller

Hi Bert, Welcome back. I'm willing to help on the LCD interface code, if you'll send me-- (1) a schematic of the board, (2) a datasheet on the LCD (or link to where I can get one) --that includes information on control and data interfacing (3) any existing code for this PIC (so I can

[time-nuts] Timelab Agilent 53230a

Hi everyone, This may be a rookie question... I am trying to measure phase noise using Timelab and Agilent 53230a but I get a This plot contains xDEV/phase/frequency data only -- no phase noise or AM noise records. I tried the following settings and other variations but still get the same

Re: [time-nuts] Time in Phone System

for a few months. I was considering adding it to my leap second measurements, but there didn't seem to be much point. David. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

Re: [time-nuts] Low noise powersupplies

Such as? david On 7/08/2014 9:30 PM, bruce-cpdlzquo8hwavxtiumw...@public.gmane.org wrote: I have a couple of these. however their noise spectral density tends to rise precipitously below 1Hz or so. There are regulators with significantly lower flicker noise. Bruce On August 7, 2014

Re: [time-nuts] FYI: NPLTime® - a new service providing a precise time signal directly traceable to Coordinated Universal Time (UTC) and independent of GPS.

on the promise. David McGaw On 8/14/14 1:34 PM, Iain Young wrote: On 14/08/14 17:24, David J Taylor wrote: The National Physical Laboratory (NPL) has signed a distribution agreement with trading technology company Intergence to deliver NPLTime® - a new service providing a precise time signal directly

Re: [time-nuts] Need help with transformer core

So we're nuts. I thought that was a given. David On 8/29/14 9:58 PM, Mark Sims wrote: Frankly, anybody that builds up a Simple Switcher type converter from scratch is more than a little nuts and/or awfully lonely. You can buy small, adjustable pre-built boards (buck or boost configs

Re: [time-nuts] 10811 Thermal fuse?

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