Re: [time-nuts] GPS altitude somewhat wrong?

On Wed, Jun 8, 2016 at 4:33 PM, Van Horn, David < david.vanh...@backcountryaccess.com> wrote: > Backcountry Access, Inc. > 2820 Wilderness Pl, Unit H > Boulder, CO 80301 USA > Google Earth has the elevation of this address as 5272' which is a good deal closer to your readi

Re: [time-nuts] Q/noise of Earth as an oscillator

ting frictional and other losses in a spinning object, with a spin-down time constant of 15,000 years. https://einstein.stanford.edu/TECH/technology1.html -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.f

Re: [time-nuts] Visiting Greenwich

Those in Australia might want to check out the traveling "ships, clocks, and stars" exhibit at the Australian National Maritime Museum in Sydney through Oct 30. I saw this earlier this year when it was in Mystic Connecticut and found it very interesting. It is also appropriate for non Time Nuts.

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

riggered directly by the PPS signal, thus eliminating any dependency on the interrupt latency. The PPS still generates an interrupt, but in the interrupt routine, all I have to do is wait for the ADC to finish, clear the Done bit, and reset the trigger. -- --Jim Harman _

Re: [time-nuts] Measure GPSDO stability with minimum resources?

phase error stays within a pre-determined range. -- --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] Measure GPSDO stability with minimum resources?

ges for the past 12 hours and 3-hour averages for the past 18 days. All this, including the GPSDO code, fits comfortably in a 32u4-based Arduino Micro, which has 32K of program memory, 2.5K of RAM, and 1K of EEPROM. -- --Jim Harman ___ time-nuts

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

t; > ___ > 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 __

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

ust 3 chips. And you get RTC functionality and battery backup circuitry thrown in for free. -- --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.

[time-nuts] Lady Heather for homebrew GPSDO

, but I would prefer a text-based rather than binary protocol and not to have to reformat all the NMEA data. Does this approach make sense, and if so which of the several standard GPSDOs would it be best to emulate? Thanks in advance for your insights -- --Jim Harman

Re: [time-nuts] Temperature (environmental) sensors

> > >> /tvb > > >> ___ > > >> time-nuts mailing list -- time-nuts@febo.com > > >> To unsubscribe, go to https://www.febo.com/cgi-bin/m > > >> ailman/listinfo/time-nuts > > >> and follow the instructions there. > > >>

Re: [time-nuts] Anyone (ideally in the UK) got a spare rotary knob for the 5370B TI counter?

You could try hooking up a transformer with a 20V secondary as an autotransformer to reduce the line voltage. On Fri, Dec 30, 2016, 9:09 PM Bob Stewart wrote: > If you can touch the heat sink for 2 seconds, you're made of sterner stuff > than I am! They run very hot. It's a

Re: [time-nuts] Lady Heather for homebrew GPSDO

data doesn't get clogged with routine data but the host can tell when to request detailed information. -- --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] time-nuts equipment verification from scratch (was: WTB: GPSDO)

e? Also I have found that not all computer USB ports can supply enough warm-up current for a 5V OCXO. Or did you use a hefty USB charger and miss out on the ability to get logging info back over the USB port? -- --Jim Harman ___ time-nuts mailing list

Re: [time-nuts] Bye-Bye Crystals

Attila Kinali > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss

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

s 2017 à 03:32, Mike Baker <mp...@clanbaker.org> a écrit : > > > > Hello, Time-nutters-- > > > > Any thoughts on what the likely accuracy of smart phone time > > displays might be? > > -- --Jim Harman

Re: [time-nuts] HP-59309A Clock counts only seconds

e > 4000's really do have a limited lifetime I'd rather use a substitute. > > Jeremy, N6WFO > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/listinfo/time-nuts > and follow the instr

Re: [time-nuts] The ultraAtomic clock for home

ction in the Southern Hemisphere. -- --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] Bye-Bye Crystals

ch make them truly awful for timekeeping applications. -- --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] Bye-Bye Crystals

On Mon, Mar 13, 2017 at 6:05 PM, Jim Harman <j99har...@gmail.com> wrote: > Some of the Arduino boards, the Leonardo for example, use ceramic > resonators, Sorry, the Leonardo does have a crystal. The original Uno had a resonator. --

Re: [time-nuts] RS232 output on a 53181A

__ > 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

Re: [time-nuts] GPS seconds conversion on an Arduino

is provided so you can see how they did it. -- --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] TruePosition on an Arduino

ime structure. Contact me off-list if you want code examples. -- --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] BTTF : Austron 1210-C Crystal Clock

___ > 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

Re: [time-nuts] TruePosition and Arduino Progress

; } } On Sun, May 21, 2017 at 2:56 PM, Jim Harman <j99har...@gmail.com> wrote: > Another way to do is to use the 1 PPS to trigger an interrupt on the > Arduino. Look at the documentation for attachInterrupt(). In the interrupt > routine, have it set a flag. The flag variable should

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

ut amplifier is pretty slow. -- --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] BTTF : Austron 1210-C Crystal Clock

an adjustable cam and microswitch. The receiver's audio was fed through the switch. I think the idea was that you could accurately measure the oscillator drift by adjusting the phase of the cam until you could hear WWV's tick during the short time the switch was closed.

Re: [time-nuts] Three-cornered hat on timelab?

gle roof in the attic. I calculate the day-to-day correlation at about 0.8. Making the time constant larger increases the variations somewhat, because the loop does not adjust as much, and they definitely get worse if I use a less optimal antenna locatio

Re: [time-nuts] TruePosition and Arduino Progress

t > make > >> that work yesterday. More to follow. > >> > >> thanks much and 73, > >> ben, kd5byb > >> ___ > >> 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. > > > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > -- > > 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. > -- --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] OCXO Vectron 218Y44442

ing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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] OCXO Vectron 218Y44442

Sorry, this image http://www.patoka.ca/Vectron-218Y2/IMG_20171015_193511542.jpg On Mon, Oct 16, 2017 at 6:22 PM, Jim Harman <j99har...@gmail.com> wrote: > In your image ...125 it looks like there is a cold solder joint near the > bottom right, in the second "column" o

Re: [time-nuts] Resoration of 5065A - continued...

rnal frequency compensation (1, 5, and 8 on the can or mini-DIP) unconnected. The 741 has internal frequency comp and uses pins 1 and 5 for an optional offset null instead. --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go

Re: [time-nuts] accurate 60 hz reference chips/ckts

ribe, 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] accurate 60 hz reference chips/ckts

ical design …... > > Bob > > There is interesting background on power grid frequency/time adjustment procedures here https://en.wikipedia.org/wiki/Utility_frequency#Time_error_correction_(TEC) and here https://en.wikipedia.org/wiki/Electric_clock#Accuracy -- --Jim Harman __

Re: [time-nuts] Discussion of precise time and frequency measurement

orth America relative to Europe. This culminated in the use of pulses on telegraph lines to transfer observatory time to remote stations. With this technique, very careful measurements, and mathematical advances they were able reduce the longitude uncertainty to less than 10 feet. -- --Jim Harman ___

Re: [time-nuts] Why discipline Rubidium oscillator?

On Mon, Nov 20, 2017 at 7:14 PM, Jerry Hancock <je...@hanler.com> wrote: > Have to do a cost/benefit analysis for the wife... I hope she is not the type of person who sets her watch 5 minutes ahead so she will arrive on time! -- --J

Re: [time-nuts] Holdover, RTC for Pi as NTP GPS source

move its pps 0.5 sec, which by my calculation would take about 41.667 seconds or about 11.5 hours. -- --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] Holdover, RTC for Pi as NTP GPS source

On Thu, Nov 2, 2017 at 9:04 AM, Chris Caudle <ch...@chriscaudle.org> wrote: > > > That sounds like you just designed the worst GPSDO ever. > > -- > Chris Caudle > > Yes but the price and power consumption are right. I guess it all depends on your ap

Re: [time-nuts] WWV or Net Clock controlled oscillator

of about 0.1 ppm.It comes in a small package but you can get the Chronodot, a breakout version with 0.1" headers from Adafruit and elsewhere: https://www.adafruit.com/product/255 You can use the Chronodot by itself or hook it to an Arduino to access the full range of features. > -- --Ji

Re: [time-nuts] Environmental sensor recommendations

ssembly + cable. Decent thermistors can > be had for less than a buck. > > -- > > > Check out ADT7420: > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ >

Re: [time-nuts] GPS coordinate differences between APRS.FI and Google Maps

Perhaps aprs.fi is reporting in dd.mm (degrees.minutes) format vs decimal degrees. That would be consistent with the numbers you are setting. On Fri, Apr 20, 2018, 8:01 PM Azelio Boriani wrote: > aprs.fi uses google maps... have you taken a look to your raw packets? >

Re: [time-nuts] 4046 replacement

, you may need to > make some changes to use the '7046 version but you can then make a value > judgement if the flaw had in fact mainfested itself as a problem in your > design? > > --Jim Harman ___ time-nuts mailing list -- time-nuts@feb

Re: [time-nuts] Yet another Arduino-based GPSDO

of it.The steps are less than I can measure What TIC capacitor did you use. If it is that temperer sensitive you might want to replace it. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin

Re: [time-nuts] Adafruit (MT3339) problems today

works in North America. I don't know details elsewhere, but the PMTK313 message says it turns searching for SBAS satellites on and off. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin

Re: [time-nuts] Frequency of LC Tank.

are driving it with the same frequency ad the same phase it naturally oscillates at -- --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

Re: [time-nuts] New timing receivers?

. I am using the Adafruit antenna outdoors, with a view of about half the sky, looking east. -- --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

Re: [time-nuts] Effects of noise on EFC line?

/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] tcxo

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

Re: [time-nuts] lightening protection of a GPSDO system / optical isolated distribution amp

is able to select the 12 BEST places GPS satellites that are in view. This is not a great effect as long as there is enough sky that there are always some in view. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe

Re: [time-nuts] tcxo

___ 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

Re: [time-nuts] tcxo

___ 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

Re: [time-nuts] SMIQ manual

-- --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] Which First GPSDO to buy?

OCXO is about $100.00 -- --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] I've designed a GPSDO, but how good is it?

line at the bottom is the value being sent to the DAC and the green line at the top is the ambient temperature --Jim Harman ___ 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] Celestial Navigation instruction being reinstated in the US Navy

o pre-pay, saving a few cents/gal and a trip inside to get my change. Surprisingly accurate. -- --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] How did they distribute time in the old days?

ervice goes back further than the turn of the 20th > century. It started in 1870. > > -- --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] UPS for my time rack

line filtering,reduced the interference significantly. -- --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] 4046 experiment for gpsdo

gt; locks a 10MHz signal to a 1Hz (1pps) signal. What makes it lock to 10 > 000 000Hz instead of 999 999Hz or 10 000 001Hz? Just the hope that the > 10MHz is exactly that? > > Cheers, > Will > > On 26/09/15 08:32, Jim Harman wrote: > > To further demon

Re: [time-nuts] 4046 experiment for gpsdo

tor has been powered off for 15 minutes, it meets these criteria in less than 10 minutes after power-up. The spec for the oscillator is that -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/

Re: [time-nuts] Value of parts for the RC network of "GPSDO with 1ns res TIC"

On Thu, Sep 24, 2015 at 10:14 AM, Jim Harman <j99har...@gmail.com> wrote: > The diode prevents it from being discharged by the LS4046. Sorry, I meant HC4046. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubs

Re: [time-nuts] Value of parts for the RC network of "GPSDO with 1ns res TIC"

-- 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] 4046 experiment for gpsdo

by an Adafruit GPS module. Presumably it would be less if I had a real timing receiver. ​. If the inserted image does not come through, I will re-send as an attachment. > > -- --Jim Harman ___ time-nuts mailing list -- time-nuts@fe

Re: [time-nuts] 4046 experiment for gpsdo

ecause I might > have overlooked something major, that will screw up the operation. > > Best Regards, > Can > > ​ > > _______ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-b

Re: [time-nuts] algorithms and hardware for comparing clock pulses

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] Newbie questions

ased on the design posted here by Lars Walenius a couple of years ago. It uses the Arduino Micro processor, which is nice because it has a second serial port. This lets it get serial data from the GPS and talk to the PC at the same time. I would be happy to post the schematics and

Re: [time-nuts] Newbie questions

gt; Figure > that you likely will read at least several hundred papers. There is a whole > statistical language that is unique to these gizmos. This is *not* a > follow a > set recipe sort of project. > Again, depends on your answer to #3. I started with a working design and code

Re: [time-nuts] Next step up from basic GPS/PPS timekeeping

n for some time, with a lot of learning along the way. Of course there are always potential improvements, but the current design works surprisingly well. If someone can provide access to a good set of test gear (I am in CT), I could better quantify the performance. My latest schematic is attache

Re: [time-nuts] Next step up from basic GPS/PPS timekeeping

weak its frequency up and down in increments of about 0.1 ppm (about 3 seconds per year). It does this by switching in and out tiny on-chip capacitors. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https:

Re: [time-nuts] Newbie questions

>> >> I have also read, more than once, statements in this forum that something >> or >> another could be had for some low, low price so why build it yourself? I >> think >> that there are several reasons, including but not limited to the >> following. >> >> 1. It is an interesting project. &

Re: [time-nuts] Home-brew GPSDO

d on another thread if you want to see the schematic. Credit for the design actually goes to Lars Walenius, who posted it here a couple of years ago. -- --Jim Harman ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo

Re: [time-nuts] When does NIST change to DST?

WWVB has sent the signal to switch to DST but the website has not changed yet. On Sun, Mar 13, 2016, 10:11 AM wrote: > I noticed that NIST, at http://nist.time.gov/ , is still sending standard > time. When do they change? > > John WA4WDL > > >

Re: [time-nuts] Conditioning Rubidium Oscillators

age TIC error at long time constants -- --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] Conditioning Rubidium Oscillators

e. > > > > On Tue, Mar 15, 2016 at 7:51 PM, Attila Kinali <att...@kinali.ch> wrote: > > > On Mon, 14 Mar 2016 19:56:42 -0400 > > > Jim Harman <j99har...@gmail.com> wrote: > > > > > > > > > Disclaimer: Control theory is no

[time-nuts] Fwd: Home-brew GPSDO

ith a circuit that uses a better current source, which I can pass along if you are interested. So far the performance seems to be about the same as this simple circuit. -- --Jim Harman -- --Jim Harman Arduino GPSDO Schematic v4.pdf Description: Adobe PDF document Arduino GPSDO notes

Re: [time-nuts] PRS10 and missing serail port communication

Make sure Rx on the converter is connected to Tx on the PRS10 , Tx to Rx, and the polarity is correct. The transmit lines should be at 0 V when idle. Not sure about the PRS10, but official RS-232 requires the idle (Mark) voltage to be -3 or lower. On Thu, Mar 3, 2016, 5:00 PM Philip Zahariev via

Re: [time-nuts] PRS 10 and serial port communication

Actually a null modem is just the device that interchanges the connections, Rx to Tx and sometimes DSR to DTR and others. The inverters are needed in this case to convert zero or negative voltage levels to positive and vice versa. On Fri, Mar 4, 2016, 6:00 PM Artek Manuals