Re: [time-nuts] Power connectors continued

I have a design rule that I've used for decades: "If it fits, it works, or it does no harm." -Original Message- Why so many connecter types? So you don't cross stuff up. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

Re: [time-nuts] How to love your Power Poles.

One thing I love about them is that you can create odd geometries. All my ham gear, and generally anything I own that's 12V has APPs in the OC Races standard. All lead acid sources are also same. I could see using a different geometry for lithium batteries and the stuff that goes with them, and

Re: [time-nuts] CRT for Tracor 527A

My message to Dan Rea are bouncing, so please forgive the BW: Dan, Hang fire please - I just got this baby hooked up and there's been some creative wire cutting done. The supplies for the CRT have been cut at the trafo. It needs lots of TLC as its not actually working right now - fun ahead.

Re: [time-nuts] KS24019 units PSU requirements

Thanks, I ordered a 24V 120W power brick from eBay. Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: 21 June 2017 16:19 To: time-nuts@febo.com Subject: [time-nuts] KS24019 units PSU requirements I have not measured mine, but I saw

Re: [time-nuts] GPS splitter

Hi Magnus - what sort of inductor value did you use? 68nH or so? Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: 17 June 2017 15:12 To: time-nuts@febo.com Cc: mag...@rubidium.se Subject: Re: [time-nuts] GPS splitter Hi,

[time-nuts] KS24019 units PSU requirements

I have a pair of L108 (RFTGm-II-Rb) and L109 (RFTGM-II-XO). What current do these bad boys draw so I don't get too skinny a 24V PSU? Thanks Dave ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] CRT for Tracor 527A

Trying a long shot here, I'm looking for a 1" CRT type 1EP1 (or 1EP11, or?) for a Tracor 527A Frequency Difference Meter. I did spot some on eBay but the vendor had a rather high opinion of their worth :) at over 300 dollars Anyone got one to spare? Thanks Dave

Re: [time-nuts] SR620 TCXO calibration

On 19 June 2017 at 21:43, David C. Partridge <david.partri...@perdrix.co.uk> wrote: > Yes please. ... > OK, the code is here http://www.kirkbymicrowave.co.uk/tmp/srs-0.02.tar.gz Note 1) It has only be tested on Solaris SPARC, with a National Instruments GPIB card. 2) I would expe

Re: [time-nuts] SR620 TCXO calibration

Yes please. ... -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David Kirkby (Kirkby Microwave Ltd) Sent: 19 June 2017 21:03 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SR620 TCXO calibration On 19 June 2017

Re: [time-nuts] SR620 TCXO calibration

actually I think mine also has an OCXO D. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Dr. David Kirkby (Kirkby Microwave Ltd) Sent: 19 June 2017 21:21 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] SR620 TCXO

Re: [time-nuts] SR620 TCXO calibration

I should have added, mine had an OCXO - I just see you had a TCXO. I don't have the SR620 any more. I swapped it, along with a HP 4.2 GHz signal generator, for an HP 4291B impedance and material analyzer. Dave ___ time-nuts mailing list --

Re: [time-nuts] SR620 TCXO calibration

On 19 June 2017 at 15:35, David C. Partridge <david.partri...@perdrix.co.uk> wrote: > I think I'm being dense, but I can't work out how to get this thing to > display CalDat 04. I have managed to get it to display CalDat 0 value, > but > can't work out how to step through to

[time-nuts] SR620 TCXO calibration

I think I'm being dense, but I can't work out how to get this thing to display CalDat 04. I have managed to get it to display CalDat 0 value, but can't work out how to step through to view adjust CalDat 04. Once I do get there, how do I manage to adjust the CalDat value while observing the

Re: [time-nuts] GPS splitter

FWIW the one I chose (V26-102LED is specified to 2.4GHz and has a real DC block on one port and DC pass on the other. They also do up to 8 way versions. At an overall cost of about USD3 or so!!! Dave -Original Message- From:

Re: [time-nuts] GPS splitter

"David J Taylor" <david-tay...@blueyonder.co.uk> wrote: .. or a ready-made, and smaller item: http://www.ebay.co.uk/itm/1GHz-3GHz-2-4GHz-Power-Splitter-Combiner-2-Way-SMA-/141740586696 I use this successfully for 1.09 GHz ADS-B splitting. Please be aware that this is a Wi

Re: [time-nuts] GPS splitter

-Combiner-2-Way-SMA-/141740586696 I use this successfully for 1.09 GHz ADS-B splitting. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv

[time-nuts] GPS splitter

Anyone in UK have a spare GPS splitter? I've decided I need more clocks :) Dave ___ 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] backfill (was: Poor man's oven)

Wouldn't the low density of helium reduce some mechanical friction? I realize the motions are small but they are motions. The "Cousteau effect"? :) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] HP8640

Hello Ulrich, I have an 8640 I was going to put up for sale in the next few weeks. It’s in almost perfect condition. All of the gears are intact with no cracks or splitting. I think this SG may have been in a lab environment most of it’s lifetime. Contact me off list if you are interested.

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

You can feed in an external AREF, but look at the data sheet for the particular AVR chip. One thing which is commonly ignored in Arduino-Land is the I/O pin leakage current and the maximum source impedance specs. You are well advised to buffer the voltage you are reading, or make sure the

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] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

On 5 June 2017 at 00:59, Attila Kinali wrote: > Moin, > > This discussion is kind of getting heated. > Let's put some facts in, to steer it away from > opinion based discussion. > I can't find it now, but I know someone said thermocouples are obsolete. I spoke to a friend

Re: [time-nuts] Machining some aluminum help!

For popping off the lid, a few threaded holes in the lid would be nice. Insert screws and let them push against the body and push the lid off. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of ed breya Sent: Thursday, May 25, 2017 3:08 PM To:

Re: [time-nuts] HP10811 Oscillator Thermal Fuse

-- Forwarded message -- From: Van Horn, David <david.vanh...@backcountryaccess.com> Date: Thu, May 11, 2017 at 4:31 PM Subject: Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse To: Discussion of precise time and frequency measurement <time-nuts@febo.com> There's an excellent

Re: [time-nuts] time.gov

Just tried it, came up 4 sec. slow. Refreshed the page and it was correct. David N1HAC On 5/11/17 7:52 PM, Jerry Hancock wrote: I checked it on two different computers and again just now, all were counting 5+ seconds slow. I then downloaded their flash app which as an option I never had

Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

There's an excellent article out there on the web called "Low Voltage, the incompetent ignition source" I highly recommend a read. I dealt with a case like this a couple years ago. Failed fet in an H bridge caused a fault which the brick SMPS picked up as a short, and went into "hiccup" mode

Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

I too have had a fuse open up due to a failed thermistor in a HP10811. David N1HAC On 5/10/17 7:43 PM, Dan Rae wrote: As I reported the last time this subject came up, or maybe the time before, the only time I had an open thermal fuse was in a 10811 that had an open thermistor. I was able

Re: [time-nuts] Anthorn eLoran

, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com

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] Reliable time from GNSS signals

nical than I had hoped from the title, being somewhat more about traceability than reliability, but I suppose it depends on your point of view! Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.

Re: [time-nuts] TAPR Oncore M12+ kit

Milling internally and externally to the perimeter of the board is a price adder, but is routinely done and not expensive. I've done round PCBs with large, oddly shaped "round" holes in the middle, impossible to drill. I've done PCBs where the outer corners had to be milled to a specific

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] Name of integral of timing residual

I think that should be "absity" (s not c) Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jim Palfreyman Sent: 20 April 2017 06:18 To: Discussion of precise time and frequency measurement Subject: [time-nuts] Name of integral of timing residual >

Re: [time-nuts] Measuring coax temperature coefficient with a TICC

Pi f C >> G, so it simplifies to sqrt(L/C). Those two assumptions become less valid at low frequencies. Overall, what you are doing seems interesting, but I would question how much the results will relate to real-world use of coax, where its not normal to have great real of it. Dr. David

Re: [time-nuts] HP E1938

I just heated up with a soldering iron and pulled out the pins of a standard DB25 connector that would get in the way. No problem, lovely budgie. David N1HAC From: time-nuts <time-nuts-boun...@febo.com> on behalf of Bruce Griffiths <bru

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] Re. DIY atomic "resonator"

On Wed, Apr 12, 2017 at 11:18:00AM -0700, jimlux wrote: > Yep. There's been a fair amount of work over the past decades on using > modulated reflectors for measuring antenna patterns (e.g. on phased > arrays). You can have a diode/dipole suspended by resistive leads (with > an impedance of

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] 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] 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] Sinlge ADC multi-band receiver

nformation is approaching 10 years old? Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To u

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 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] 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] 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 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)

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] HP-59309A Clock counts only seconds

You can get a brand new CD4011BE from pretty much most suppliers at about 15 cents that won't exhibit the problems of the earlier ones. Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Jeremy Nichols Sent: 04 April 2017 00:44 To:

[time-nuts] Oscillator Maker is hiring

. Please contact me if you are interested - even in positions in other groups. dt...@sitime.com<mailto:dt...@sitime.com> Best regards, David ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/m

Re: [time-nuts] GPS first LO need to be locked?

links [2] and [3] give 404 errors Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Attila Kinali Sent: 31 March 2017 12:35 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS first LO need to be locked? [2] "A

Re: [time-nuts] more of a time distribution question

/product/746 Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

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] PLL performance?

But I assume the drive for the pendulum is some impulse. Not the old > mechanical clock with a spring for power. > Regards > Paul > WB8TSL > > On Wed, Mar 22, 2017 at 7:48 PM, David Scott Coburn <scot...@optonline.net> > > wrote: > > I will not be using an off-

Re: [time-nuts] PLL performance?

; so easy. Hall/optical have a softer switch on/off curve. Depending what you > choose to instrument your pendulum may also introduce more jitter. The > 20logN dosen't help either, 1 millideg at 0.5 Hz is 5.5 cycles at 1 MHz. > > On Mon, Mar 20, 2017 at 9:07 PM, David Scott Coburn <sco

Re: [time-nuts] Time Dilation tinkering

Aiguille du Midi is 3842m IIRC (cable car base station at about 1000m). Dave -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of jimlux Sent: 22 March 2017 14:57 To: time-nuts@febo.com Subject: Re: [time-nuts] Time Dilation tinkering On 3/22/17 4:04 AM,

Re: [time-nuts] PLL performance?

an long lock times. Very > long lock times. Engineering is the art of making what you want from what > you can get at a profit. I like Polywell Fusion. > > > On Tuesday, March 21, 2017 2:01 AM, David Scott Coburn > <scot...@optonline.net> wrote: > > > >

Re: [time-nuts] PLL performance?

Thanks Tom. Scott On Tuesday, March 21, 2017 2:08:14 AM EDT Tom Van Baak wrote: > Andy, Bill, et al. > > Attached is a GIF version of Scott's (unreadable?) > histogram-utcday21613x.pdf file. > > /tvb > > - Original Message - > From: "Andy" > To: "Discussion of

Re: [time-nuts] PLL performance?

r, it does show that my TSC triggering and latching circuits are working correctly.) > > http://www.thinksrs.com/assets/instr/PRS10/PRS10diag2LG.gif > > Some additional GPSDO, pendulum/PLL, pendulum ADEV links: > > http://leapsecond.com/pages/gpsdo/ > > http://leapsecon

Re: [time-nuts] PLL performance?

Ack! Sorry for the questionable PDF file. It was generated by gnuplot on my Linux system. I see that Tom has posted a gif of the image, so I won't duplicate it. Cheers, Scott On Monday, March 20, 2017 10:36:05 PM EDT Bill Byrom wrote: > Hi, Scott. I rarely post here, but just noticed your

Re: [time-nuts] PLL performance?

On Tuesday, March 21, 2017 12:26:59 PM EDT Attila Kinali wrote: > Moin, > > On Mon, 20 Mar 2017 21:07:03 -0400 > > David Scott Coburn <scot...@optonline.net> wrote: > > I have built and tested a PLL circuit that will be used to generate a 1 > > MHz > >

[time-nuts] PLL performance?

Hi All, I have built and tested a PLL circuit that will be used to generate a 1 MHz signal locked to a 0.5 HZ signal from a pendulum. (Details available upon request.) The circuit is a classic 4046 generating the 1 MHz signal which is fed into a 2e6 digital divider which outputs 0.5 Hz which

Re: [time-nuts] Best Chance GPS module

On Dec 1, 2016, at 7:44 AM, David J Taylor <david-tay...@blueyonder.co.uk> wrote: Venus838LPX-T. Seems to go into a non-locked state for a proportion of the time but still emits a PPS signal, which increasingly deviates from true UTC. That's using a 25 mm square 28 dB active patch a

Re: [time-nuts] Smart Phone time display accuracy...?

ee: https://itunes.apple.com/gb/app/emerald-time/id290384375?mt=8 where it's -0.001 Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv __

Re: [time-nuts] MSF maintenance day

I recorded one of the 2009 outages: https://www.youtube.com/watch?v=1vQPgcja770 I probably have some of the raw data somwhere. They actually turned it on and off a few times over the period. David. ___ time-nuts mailing list -- time

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] Bye-Bye Crystals

In my design I need 10ppM, and then I divide by 8. Software can't correct for anything. -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Bownes Sent: Tuesday, March 14, 2017 10:50 AM To: Discussion of precise time and frequency measurement Subject:

Re: [time-nuts] Bye-Bye Crystals

I work for a company that builds electronics products, low volume, highly complex units. It used to be that you bought a crystal and then made an oscillator that would use that crystal. Or you had a single chip micro that used a crystal for the time base, in the early days you might have to

Re: [time-nuts] Bye-Bye Crystals

Probably true for many things. My current design has six crystals, and exactly none of them could be replaced by an oscillator module. Power and space considerations mostly. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

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] HP5065A Rubidium questions: some progress

I installed a 10 ohm 1/2 watt carbon resistor and the Rb lamp came right on!  Woo-hoo! I will get a better quality, high temperature resistor to replace this one.  (RN70?) How critical is the resistance value?  10 ohm?  12?  Is there a way to test for an optimum value? Scott On Tue,

[time-nuts] HP5065A Rubidium questions: some progress

Hi All, Thank you all for the very helpful suggestions! I will try to reply to you all in this one post. I opened up the A12 assembly and was happy to find that the lamp, windows, and reflector all appear to be in good physical condition.  There is some very light corrosion on the

[time-nuts] HP5065A Rubidium question

I have an HP5065A Rubidium Frequency Standard which is not working. All of the oven temperatures look OK. The power supply voltages look OK. The ~60 MHz going into the RVFS package looks OK. The 5.000 MHz and the ~5.315 MHz signals are within a few Hz. (The unit is running open loop only.) The

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

, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com

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

252 145.238.203.14 2 u 487 64 200 37.210 -0.725 13.232 73, David GM8ARV -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-n

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] Vintage Frequency Measurement

On 12 February 2017 at 06:08, Scott Stobbe wrote: > I was inspired recently coming across a Lampkin 105 frequency meter, as to > how frequency measurement was done before counters. > > Certainly zero-beating a dial calibrated oscillator, would be one approach. > > Is

Re: [time-nuts] u-blox NEO-M8T GPS initial tracking test

This behavior is described in the document: u-blox 8/M8 Firmware v 3.01 for Standard Precision GNSS, Release Notes This document says, among other things,: "New multi-GNSS messages use UTC as

Re: [time-nuts] how many seconds out does GPS discipline being to improve Rubidium stability?

). [] While you are waiting for your Rubidium, perhaps this little GPS box may help? http://www.leobodnar.com/shop/index.php?main_page=product_info_id=234 Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay

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] 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

[time-nuts] HP 5061A Cesium Beam Std

Hello Time Nuts Friends, I have acquired an HP 5061A off of EBAY and I believe the cesium beam tube may be bad. The ion pump meter pins out and never comes down to a reasonable level. I don’t have an external HVPS to check the tube as suggested in the manual. I’m thinking the worst here… that

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

On 9 February 2017 at 21:31, Poul-Henning Kamp wrote: > > The only other possible "balance signal" is the voltage, and it > suffers from a host of noise mechanisms, from bad contacts and > lightning strikes to temperature, but worst of all, it takes double > hit when you

[time-nuts] u-blox NEO-M8T GPS initial tracking test

I am doing similar tests, seeing similar results. I have 5 x NEO-M8T's, 3 M6T', 4 Skytrack Venus 838Lp-T's. Mostly have Toaglas triple band antennas on PCB groundplanes with LNA-SAW-LNA conditioning in line. I have built a three arm test rig (arm < =1.5 M) for testing RTK measurments, etc.

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

[time-nuts] HP 58503A GPS time and frequency receiver - How do I determine why the ALARM LED is on?

I've got an HP 58503A purchased from China a couple of years ago. It has a bit of a hard life, having been in water at some time. But it seems to work ok, as far as I can tell. Today there was a power failure for 5 minutes or so. The red ALARM LED is on. It is not clear to me why, although of

Re: [time-nuts] Thermal effects on cables

On 23 January 2017 at 17:29, Tim Shoppa wrote: > > Funny how people always want to put the words "dielectric" and "constant" > right next to each other but we know it isn't constant :-) > > Tim N3QE > Yes. I will have to look into this, as I see some quite widely different

Re: [time-nuts] Thermal effects on cables

oI On 23 Jan 2017 17:02, "REEVES Paul" <paul.ree...@uk.thalesgroup.com> wrote: > > Hi David, Hi Paul > Surely the impedance of the cable is only affected by the ratio of the inner conductor and outer conductor diameters modified by the internal dielectri

Re: [time-nuts] Thermal effects on cables

On 13 January 2017 at 06:52, Ole Petter Ronningen wrote: > Hi, all > > The question of phase shifts in cables pops up every now and then on this > list - I stumbled across a good table of measured phase shifts with > temperature in different cable types in this paper: >

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

From: Charles Steinmetz Try this: <https://www.thehenryford.org/explore/innovation-nation/episodes/ron-popiel/> Best regards, Charles = Not for the UK, it seems. Is it on YouTube? Could someone upload it somewhere? Thanks, David -- SatSignal So

Re: [time-nuts] HP 55300A Date Problem

On 21 January 2017 at 17:29, Gary Neilson wrote: > I have a HP 55300A Telecom Primary Reference Standard that I am using as a > frequency reference (10 mhz) in my lab. > I suppose this is one of those open-ended questions, but what the definition of a "Primary Reference"?

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] 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

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] 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

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