[time-nuts] How can one measure ADEV of a good oscillator?

Just because it's a maser does not mean it has good ADEV. Masers use the hydrogen physics package to discipline an external oscillator just like a GPSDO uses GPS. So a maser can be considered to be a HDXO... hydrogen disciplined crystal oscillator. Your maser ADEV is only as good as its

[time-nuts] Wall clock stepper driver board and funky firmware

I was scanning through the shared PCB projects on OSHPARK.COM and came upon this little driver for stepper motor wall clocks: https://oshpark.com/shared_projects/gpkIWuAW There is a link to github with various AVR firmwares for doing different random ticking clocks, a Mars clock, a tide clock,

[time-nuts] gravity, space and time

My Mickey Mouse watch was... it detected a gravity anomaly when the strap broke and it hit the garage floor. This apparently caused a complete cessation of temporal flow around the unit, ;-) - Our clocks aren't good enough.

[time-nuts] Ventilation of HP 58503A GPS time frequency reference receiver

Ebay is your friend when you need footsies for your old HP equipment... just search for HP FEET and you should be able to find what you need. As usual, you will find sellers with reasonable prices and those that think they are made of 25k gold.

[time-nuts] GPS position averaging

Take a look at the code in Lady Heather that does a 48 hour precision survey. It calculates a weighted median position of fixes over 1 hour periods then calculates a final position from those medians. The algorithm was developed by having people around the world with Thunderbolts and quality

[time-nuts] Lady Heather and comm port setup...

Since version 3.1 Lady Heather should be able to find a 9600,8,ODD,1 device. This was added for the Resolution T timing receiver. It may take it a minute or so for it to figure out. If the program does not see a valid receiver version message within 30 seconds or so it toggles the parity

[time-nuts] HP 5370A to B conversion

It's not practical to convert an A to a true B model. They use a different input front end circuit. But, the rest of the machine is compatible. The B firmware runs on a A. John's CPU board works on either version.

[time-nuts] Cheap 5370A on eBay

I believe there are 5370 ROM dumps on KO4BB.COM I few years back i posted on this forum how I restored a 5370A that had a missing ROM board by installing an EEPROM into the empty socket on the CPU board. I did have to jumper a couple of address lines to the EEPROM and perhaps tweak the

[time-nuts] New Years Eve TV countdown

Also, ever since the infamous Janet Jackson wardrobe malfunction almost all live TV in the US is on a mandatory delay of several seconds so that offensive (?) images and language can be censored. I have a DTV-PAL over-the-air DVR box (made by Dish/Channelmaster, long since discontinued).

[time-nuts] T.I. questions

Several of the reciprocal counters (DC509, DC5010) Tektronix built for their TM500/TM5000 test equipment mainframes use a National Semiconductor noise generator chip to dither their reference clock. They do this mainly to handle the case where the input freq and reference clock are very close.

[time-nuts] 10544A vs. 10811

I have had over a dozen HP5370 counters that used the 10544A. I have noticed the 10544A's tend to have quite a bit better aging characteristics than the 10811A. As with all things oscillatory, it could just be luck of the draw or due to the fact that they are older than the 10811's and have

[time-nuts] Maser on a chip

http://www.princeton.edu/main/news/archive/S42/13/37M75/index.xml Not much detail there... but there is an article in Science. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] GPS leap second pending (TBolt/Heather)

Nope, it's not an error or a problem. That column of data is showing a decode of the 16 status bits that the Tbolt is providing.The Trimble docs say that bit is a Leap Pending bit, so that is what Heather displays. It would be wrong to try and mask/adjust the report of the receiver's

[time-nuts] Mechanical 1PPS Oscillator Disciplining

Many years ago I built a GPSDPO (GPS Disciplined Pendulum Oscillator). A friend of mine inherited a grandfather clock built in the late 1700's. She had the movement cleaned and serviced and got the clock working fairly well, but it was not all that accurate. I built up a device using a

[time-nuts] A novel use of Injection locking of ring oscillators

Every good time nut knows about the hazards and subtle wonders of unintentional injection locking of oscillators. Other people apparently don't... How forced injection locking of ring oscillators can be hazardous to your wallet:

[time-nuts] Problems using digital TV signals as a time source

A little while back there was a discussion about some of the issues using the PSIP data from digital TV broadcasts as a time source... it's not a good idea. Here is some data of why not: http://home.earthlink.net/~schultdw/atsc/tdata/index.html And when daylight savings time gets thrown into

[time-nuts] TimeLab with Wine: No RS232 interface available

I have seen several issues with Windows programs not releasing (or perhaps not being able to releaase) the serial ports after using them. Once one of these programs accesses the serial port, no other programs can use it until you re-boot. I'm fighting windoze Hypertrm right now over this

[time-nuts] Using oscillators to measure earthquakes

Today the Dallas area has been experiencing several eathquakes. The largest were magnitude 3.2, 3.6, and 3.1 at a depth of around 4km.They happened around every three hours. I am around 5 miles from the epicenter. They are strong enough to shake the house quite a bit. The largest put a

[time-nuts] Lady Heather

Lady Heather is set up to run the serial port at 9600,8,N,1 If it sees data errors, after around 20-35 seconds or so, it toggles to 9600,8,O,1 This feature was added to support the Trimble Resolution timing receivers. You can try the /rt command line option and see if that makes any

[time-nuts] Quantum entaglement rubidium clock

http://www.theregister.co.uk/2015/03/30/photon_plays_sheepdog_with_nearly_3000_atoms/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

[time-nuts] Recording mains frequency/phase [WAS: No GPS satellites]

When I first came across that article on theregister.com, I thought that it was a rather cute idea and decided to give it a try. I set up a couple of data recorders that logged AC zero crossings to an SD card (with 64 Mhz clock resolution). They were set up around 8 miles apart. I also

[time-nuts] new tdc from Texas

Sparkfun is selling a board (around $15) based on the STM VL6180 chip that measures distance based upon time-of-flight of pulses from an on chip (or at least in-package) VCSEL IR laser. Claims to have a range of 0 .. maybe 30 cm. Unfortunately it doesn't look like you can directly access

[time-nuts] Leica AT-303

The L1 only antenna that did very well was an AeroAntenna AT575-75W-TNCF-000-RG-26-NM Also a Racal LandStar MK4 did well. These are both small L1 only survey antennas. All my L1/L2 antennas are choke ring survey/geodetic grade devices... an equivalent choke ring L1 only antenna should

[time-nuts] Tuning a Trimble Thunderbolt

Lady Heather has a display option (G L) for blanking out the location display... no need to mess with Photoshop... Ok, my *assumption* is that the location data has been Photoshopped. Normally that is not worth commenting on. It’s something that a lot of people do.

[time-nuts] Tuning a Trimble Thunderbolt

On a Thunderbolt, you can only manually enter your position with using single-precision floating point numbers... not really accurate enough for a time-nut. When Lady Heather does a precision survey, it stores the high-prescision results of the 48-hour survey by doing repeated single-point

[time-nuts] Tuning a Trimble Thunderbolt

A couple of thinks to note: Before running the auto-calibration feature, first set the antenna elevation mask angle to a low value and let it run for a few (say 12) hours. This will collect data on the received signal strength vs satellite elevation angle. The auto-calibration routine sets

[time-nuts] Leica AT-303

At least with a Tbolt, they do help... and quite a bit. When I was writing Lady Heather's precision survey code I tested it with several antennas (comparing the results to a cm level L1/L2 survey). The Leica antenna and a couple of other survey grade/choke ring antennas were, by far, the

[time-nuts] CM level GPS accuracy in a smartphone

Should be fun when it becomes available... they claim they can get accurate carrier phase info using a cheap antenna in the phone... and in real time. It should also be able to get accurate time. http://www.eurekalert.org/pub_releases/2015-05/uota-ncg050415.php

[time-nuts] GPS week rollover

Well, a big one will be in 2017 when all our Tbolts roll over.I have included some code in the next version of Lady Heather to compensate. If it detects a year from the unit before 2015, it converts the date/time to Julian, adds 1024 weeks worth of seconds, and then converts the

[time-nuts] lawnmower robots may be the end of VLF timekeeping

iRobot (the Roomba vacuum cleaner people) have applied for an exemption to allow them to send beacon signals in a 6-7 GHz band to fence in their new lawnmower. The band they want to operate in is apparently for indoor only low power applications. The easy solution is to just buy some goats...

[time-nuts] Visual clock comparison

The problem is the human visual system only processes one object at a time. You can't look at and compare two separate items simultaneously. You could minimize the effect by placing one clock face directly in front of the other with like only the 12:00 positions visible (or two LEDs next to

[time-nuts] UBlox GPSDO

The SiLabs part only supports loop filter time constants down to 60Hz. GPS loop filters usually use values in the 100's to 1000's of seconds. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Close in phase noise of microwave VCOs

If you want to play with a homodyne doppler radar, search Ebay for hb100 microwave sensor. It is a cute little 10 GHz doppler module that costs around $6. It can be operated in continuous or pulsed mode. The output does require a couple of op-amps to get a TTL level output.

[time-nuts] Electronically Disciplined Mechanical Pendulum

Several years ago (OK, the last millenium) I GPS disciplined a friend of mines 200 year old grandfather clock that she had inherited. I used a solenoid to nudge the pendulum. Surprisingly, it worked quite well the first time. The biggest problem was the pendulum did not swing at a 1Hz

[time-nuts] Cheap 48V 2A power supply

BG Micro has some nice 48V 2A power supply modules for around $12. IEC power cord in (100-240V), 2.1mm barrel connector out. Seems to work well with my Nortel GPSDOs, but I haven't scoped the thing out for noise, etc.

[time-nuts] How Microsoft cloud services will handle leapseconds...

Sounds like very poorly to me... http://www.theregister.co.uk/2015/05/29/windows_azure_second_out_of_sync/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Casio Watches 13 Year Drift in Seattle

A friend of mine is the test engineer/clock guru for one of the major manufacturers of clock chips. Rest assured that all watch makers know the usage profiles for their customers quite well and they do indeed tweak the chip to compensate for the typical profile. If your usage pattern does

[time-nuts] You need one of these to improve your time-nuttery.

I wonder how much such an environment would improve time-nut equipment performance and measurements? They claim a 2-3x resolution increase in a STM. http://arstechnica.com/science/2015/07/inside-the-quietest-room-in-the-world/

[time-nuts] HP10811 dual oven

I laid out a through-hole version of Warren's board in Eagle and had OSHPARK fab up three of them. I sent one to Warren and am using the other two. The one mod I made was to use a single darlington TO-220 instead of the two transistor stage that Warren used. They seem to work quite well. I

[time-nuts] Would this work as a frequency standard? Would it damage the Stanford Research function generator?

If the SRS stores the CALBYTES info in EEPROM, continuously updating it will wear out the EEPROM in a relatively short time. There were some proposals about interfacing the freq adjust up/down buttons in the FEI Rb modules to steer the device... I calculated that the EEPROM would be

[time-nuts] 5370A Trigger

The 5370 cooling fan blows across the chassis directly onto the input board. The switches are basically gold plated strips on springy material that slide on the circuit board. They are open to the world and not sealed. Dust and fluff accumulates on the board and into the switches. You

[time-nuts] Celestial Navigation instruction being reinstated in the US Navy

It's also interesting that they are not teaching/using printed tables. They enter the readings into a computer to calculate the location... assuming the computer has not been EMP'd or hacked. It's much harder to EMP/hack a book. I was taught the subtle wonders of celestial navigation in

[time-nuts] Leap seconds coming up for debate, yet again

http://www.theregister.co.uk/2015/10/29/leap_second_international_comms_conf/ Interesting take-away... 2012 leap second caused lots of snafus... 2015 leap second barely noticed. The computer world seems to have finally payed the leap second the respect that it deserves and now has it under

[time-nuts] When NTP goes wrong...

One interesting thing in the paper was that they scanned the entire IPv4 internet address space and found around 13 million NTP servers. Around 3 million of them were serving up the incorrect time. ___

[time-nuts] Using borked Galileo sats to measure relativity

http://www.theregister.co.uk/2015/11/10/borked_eu_gps_satellites_braincheck_einstein/ Now, for 140E-6 bonus points, spot the error in the article... ___ time-nuts mailing list -- time-nuts@febo.com To

[time-nuts] Thunderbolt "osc age alarm", where to get replacement oscillator?

My bet is was just a power glitch or a corrupted message that raised the alarm and that your unit is OK. If the error reoccurs then you may have a hardware problem. There is an undocumented message that you can send to the unit to set the allowed range of the EFC signal. Default for the Tbolt

[time-nuts] modern electronics education/jobs (was:

When I was in high school (early 1970's) I designed and built my own alarm clock out of TTL... (none of that sticking the guts of a commercial alarm clock in a pencil case that get kids arrested today). Also built my first computer by interfacing a TV Typewriter to a calculator chip. I was

[time-nuts] Time syncing WiFi routers using FM radio

Something tells me these guys haven't a clue... http://www.theregister.co.uk/2015/11/11/boffins_teach_routers_to_tune_in_and_dance/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] How did they distribute time in the old days?

A friend of mine built a clock that they used to time-sync a lot of those stations. It was basically a nice OCXO built into an ammunition can. They flew it to various stations around the world. One particular trip to sync the stations in the mid-east was particularly interesting... ammo

[time-nuts] KS-24361 REF-0 standalone

On the new board, I would add a header for GPS TXD/RXD/PPS/PWR/GND to make it easy to play with different GPS modules... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] UPS for my time rack

How could anybody possibly accept/consider/use a VAX/Unix as a solution to any real computer problem? The manual set only takes 3 feet of shelf space. Anybody knows that a real (IBM) computer requires 80+ feet of documentation. Or so I was once scolded by the management of a Very Large

[time-nuts] Number of GPS sats in the sky?

The GPS system is pretty much limited to 32 active satellites. There are currently 29 satellites broadcasting usable navigation data. Plus some WAAS signals from geosynchronous orbit. ___ time-nuts mailing

[time-nuts] CS frequency standard

The tube has a finite life time (probably less than 7 years of on-time, maybe as low as 3 years) and costs a BUNCH to replace. I only run mine when I need to. I warm mine up overnight before I use it to let it stabilize. Plus make sure you run it for a day or two every 6 months or so to keep

[time-nuts] Number of GPS sats in the sky?

My tbolt is reporting 29 currently active PRNs... 27 Sats in the sky. ___ 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

[time-nuts] PM6681 and Timelab (was: PM6680 or 53131A for TimePod)

Not only battery backed up SRAM but EEPROM config data has problems. I'm a bit of a mass nut and have seen lots of old precision balances (i.e. Sartorious and Mettler) that used first gen serial EEPROMs to save their cal/config data. Lots of these are going senile. I had to build

[time-nuts] Vanguard Ultra precision Golden Oscillator

Real time nuts use Comet Cleanser to raise their xtal frequency and a graphite pencil to lower it. Only crystal cretins would use toothpaste ;-) All my FT-243's are more acc'rit than those new-fangled silly slezium and rubitinium oscillators and masery thingamabobs. Geeze, them youngin's

[time-nuts] syncronized clocks

A friend of mine is the clock chip guru at one of the major semiconductor manufacturers. He said that the jitter in clock chip oscillators is rather horrendous. Getting an oscillator to reliably start and run smoothly on nanowatts of power is the major design issue for clock chips. Jitter

[time-nuts] Einstein Special on PBS

Another thing to consider is the gravity anomaly caused by that hunk of granite beneath your clock (or above it in a mine). Hmmm, what is the clock shift at the top of Mt Everest that is due to the mountain and not the altitude?

[time-nuts] Einstein Special on PBS

Yep, been there, done that... I own a Worden gravity meter. Gravity mapping is a highly developed technology. Not just Everest, but the whole planet: ___ time-nuts mailing list --

[time-nuts] soldering QFN (was: GPS down converter question)

These are a fairly nice and cheap hot air tool. The really nice thing is they have been reverse-engineered and an open-source firmware is available. I have one. Have also built a nice reflow oven out of a $40 Walmart toaster oven... I used the temperature control PID code out of Lady

[time-nuts] soldering QFN (was: GPS down converter question)

OSHSTENCILS.COM make excellent laser cut kapton solder paste stencils for dirt cheap. I have had stencils in the mail the same day I sent them gerber files. OSHPARK does good work for boards, but they can be expensive for larger boards or quantities. I usually use gojgo.com (in China, but I

[time-nuts] Mechanical clock sound pickup circuit

And check out Bryan Mumford's stuff at bmumford.com ___ 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] Trimble Thunderbolt E frequency pulling.

My bet is interaction of the load current and power supply with the EFC and/or OCXO. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

[time-nuts] Einstein Special on PBS

The GPS spec implies the satellites have a fixed frequency offset to compensate for relativistic effects. But do they actually dynamically and/or individually adjust the frequency to adjust for orbit variations and eccentricities?

[time-nuts] PM6681 and Timelab (was: PM6680 or 53131A for TimePod)

I once got in around 20 Tek DM5?? GPIB DVM modules for the TM5000 series mainframes. They have a rechargeable nicad pack soldered to the circuit board. All the meters still had good cal data but the cells were on their way out. The meters are a pain to re-calibrate... I used a DIP clip

[time-nuts] time sync from cellphone TO microcomputer

Check out the ESP8266 based wi-fi modules. They are dirt cheap (< $5) and tend to have excellent range. Sparkfun has some that are nice (and more expensive) that break out all the processor pins. The ESP8266 is a 32-bit processor with on-chip wifi. The ESP8266 are now supported in the

[time-nuts] Lady Heather Server On Raspberry Pi 2 Model B?

> I wonder if I've got anywhere near the skills to do it... Probably not right now... it's not so much as knowing C, it's knowing the ins and out of knowing how your operating system (Windows, Linux, etc) interfaces with your hardware (display, mouse, serial port, keyboard). Basically, if

[time-nuts] Glass Envelope Quartz Crystals

> The dynam al capacitance is a couple of fF, and thus R1 is between 10k to 80k > depending on the size A friend of mine has been fighting a 32 kHz clock problem on an ARM processor (used to wake up from periodic sleeps). In discussions with the CPU and crystal makers it looks like some of

[time-nuts] Cheap hot air station

I'm partial to the Youyue 858d. Not because it is particularly good, but because there is some nice open-source firmware for it. It's also rather inexpensive (around $40). Note that there are a lot makers of -858d stations. Not all use the AVR chip that the open source firmware runs

[time-nuts] GPS Outage

> When is some organization going to explain what happened in February for > almost two hours starting at 00:16 GMT? That subject has gone silent. Rob, > NC0B I heard back from NAVCEN. They said it was a Trimble issue and that Trimble would contact me (they didn't). But that does not jive

[time-nuts] HP 10544A Repair

Also, when messing with a 10544A be aware that that the frequency tuning adjustment must be made with an insulated tool. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] HP 10544A Repair

Not to mention that a lot of pots that have been sitting at the same setting for years tend to distort the resistance element where the wiper has been making contact. Then when you make a small adjustment you cannot reach the value that you need. Ahhh, the subtle wonders of aligning old

[time-nuts] low noise multiplication to 100 MHz

Actually not hard to do... lay out circuit board (free version of Eagle), have boards fab'd at Oshpark.com or your favorite Chinese proto shop (I like gojgo.com). Have solder paste stencil made at oshstencils.com. Squeege solder paste down with a credit card. Place components by hand.

[time-nuts] Trimble Thunderbolt error

Yes, all satellites dropped out from 00:16:51 to 01:54:02 UTC in Dallas, Texas. Was tracking 5 sats then, poof, none.Global warming? Gravity waves? More bogus GPS control segment uploads? Somebody gots some 'splain to do...

[time-nuts] Trimble Thunderbolt error

I filed an outage report with NAVCEN via their web site and got an email back asking for more info (which I supplied). I got the impression that they were not aware of what was going on. Googling around also does not show any official reports of problems. Rather surprising considering the

[time-nuts] Trimble Thunderbolt error plot

Attached is a Lady Heather plot of the "event". Note that there were a couple of brief places during the outage where one satellite was tracked. ___ time-nuts mailing list -- time-nuts@febo.com To

[time-nuts] NIST quantum thermometer

NIST is working on a quantum thermometer. Apparently the current version is not very accurate, but they are working on it. If it ever comes to be, should be interesting... particularly when paired with their photonic thermometers.

[time-nuts] BG7TBL GPS Disciplined Source

I believe that it was mentioned here that the BG7TBL GPSDO disciplined oscillator controls the OCXO using a FLL (frequency locked loop) instead of a PLL (phase locked loop). Their implementation causes a slight error in the output frequency. Search the time-nuts archives (best to use Google)

[time-nuts] Best Rubidium Frequency Standard

Mark's Law of Rubidium Goodness... the bigger the box, the better it is. The HP5065A is one of the best units ever made. It can rival a cesium beam unit. The X72 is a horrid little creature. I would also go with the M100 / FRK units. The LPRO an FE56xx units were designed for telecom use

[time-nuts] Difference between Oncore models

When an old electronic gizmo starts failing across multiple units, the culprit is almost always failing electrolytic capacitors. Check your GPS board for electrolytic caps and replace them. There could be some other component that is susceptible to an age-related failure mode, but caps are

[time-nuts] Best Rubidium Frequency Standard

In many ways the 5065A is the probably the most repairable of all the units (closely followed by the FRK family and the M100). They all use parts that are mostly still available and the circuitry is accessible. You can assume that the lamp (and maybe some of the microwave parts) in any Rb

[time-nuts] LEA-M8T

Yes, they do. They seem to use different orbital, gravity, geoid, TAI, etc models. Trying to merge fixes from different systems leads to all sorts of problem, particularly at nuttery levels. I've seen reports that GPS and GLONASS fixes can be off well over 50 meters when referenced to the

[time-nuts] Building a mains frequency monitor

And that can be very interesting... a while back I read some stories on how the NSA, police, etc could find out where an audio recording was made by correlating AC hum in the recording with logs that they had of the power grids. Apparently logging AC mains is rather popular among the spooky /

[time-nuts] How to run Lady Heather under Windows10

Another issue is that FTDI is back at it again with making their drivers incompatible with clone FTDI chips. Their previous attempt actually bricked the clone USB interface chips. Their latest driver just sends garbage out the serial port. If you are using a cheap USB to serial converter

[time-nuts] Possible STEL-1173 replacement

Apparently the PLCC version of the chip is a lot easier to find than the DIP chip. One could make an adapter board to use the PLCC in a DIP socket. The PLCC will probably not fit between the rows of legs of the DIP, so the adapter would need to be bigger than the DIP footprint. Or if

[time-nuts] LPRO-101 BITE (~lock) Signal Always Low

Try iy with a pull-up. I have seen LPROs with an open collector type of output. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

[time-nuts] Datum StarLoc II and LH

Heather can log the binary packets that it sees.Use keyboard command "oj" to toggle packet logging mode. Then use the "wlw" command to open the log file. Let it run for a couple of minutes. Close the log file with "wls".

[time-nuts] Reliability of atomic clocks

> Mil-spec parts would be somewhat more reliable than commercial parts. Actually, that is seldom true. The main difference between mil-spec parts and commercial parts tends to be in the post-packaging device testing (e.g.. extended temperature / voltage range). They usually have the same guts

[time-nuts] Lightning 1, tbolt 0.

On the subject of RS-232 converter chips... I have had problems running MAX3232's at 3.6V. Sometimes they work, sometimes they don't. Sometimes they get freaky hot. The general symptom seems to be no -6V output. I've never had problems running MAX232A's at 3.6V, even though they are

[time-nuts] Trimble Thunderbolt GPSDO Troubleshooting

Well, if you think the 5V ref is bad, you could pull the ref chip and jumper the logic 5V to its output pad (through a resistor... maybe 1K) to do a quick and dirty test. If the resistor output is dragged down, you know something is loading down the ref voltage.

[time-nuts] Lady Heather coming soon to a Linux box near you...

> This is great news. Will the code be available for inspection / > modification?Yes. It is the same source code as the current version. Just > compile under Linux and voila... The code currently has a no-commerical > copyright on it, but I am going to GPL it (if I can ever figure out what

[time-nuts] A better Lady Heather 4.0 download page

John Miles is now hosting the latest Lady Heather 4.0 files. His server is a little less skeezy than tinyupload.com (which on Windows machines apparently offers to update your Java with about every click). I've used tinyupload for years on a Mac, and never got such a "generous" offer. No

[time-nuts] Lady Heather Ver 4.0 beta test available (has Linux support)

I have uploaded a ZIP file to tinyupload.com with the source and a Windoze .EXE file for the beta test version of Lady Heather. For Windows users, copy the heather.exe to your current Lady Heather directory (might want to first rename or copy your old heather.exe as a backup. For Linux users,

[time-nuts] Lady Heather coming soon to a Linux box near you...

She lives! She sings! She dances!Turned out it was not the serial port that was blocking... it was the X11 event handler. XNextEvent blocks if no event is pending. There is a X11 call that got around it... So far everything seems to be working well. I still need to do a lot of detail work for

[time-nuts] Lady Heather coming soon to a Linux box near you...

>Would there be enough horsepower for a Pi 3 to run Lady Heather and act as a >stratum 1 NTP server? I suspect so, the PI3 has quad core 64-bit capable 1.2GHz processor. The PI3 seems to be about 50% faster than the PI2. It also runs about code about as fast as a 2 GHz Pentium 4. But the

[time-nuts] Article on leapseconds

Ars Technica just published a piece on leapseconds. There is some interesting info on what makes the earth a poor clock and our abilities to measure it (want to smooth it out a bit... cut down all the trees).

[time-nuts] Lady Heather coming soon to a Linux box near you...

The question came up about Lady Heather's system usage on a PI3. Turn's out she's quite the little resource hog. CPU usage hovers between a whooping 2 and 3 percent ;-) Running on a PI2 showed about the same. Slinging a window violently around on the srceen and it peaks to around 20%. So

[time-nuts] Last Call Group Buy Ublox LEA-6T

There is what looks like a decent carrier board for Ublox modules on OSHPARK.COM's shared project library. It has a voltage regulator and RS-232 interface on it... would be nicer if it had a prototype area and swoopty PPS driver, but I'm too lazy to lay out a better one. Three boards will

[time-nuts] Looking for a Linux user with a Z3816/Z3815/HP5xxxx

I have added some code to Lady Heather to talk to SCPI GPSDOs (also Motorola, Ublox, and NMEA) and am looking for a guinea pig to test it... I have a Z3801A and want to see if it is also 3815/3816/etc compatible. Please contact me off list. I might be able to send a WIndows .EXE , but a lot

[time-nuts] I thought GPS repeated every 12 hours (-2 minutes)

Lady Heathe does have sidereal time support. Set the time zone name to LMST or GMST or LAST or GAST and you get sidereal times... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

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