[time-nuts] Where the 5370's are...
if New Mexico is really a legitimate US state. I dunno, I've been there. Was exposed to bubonic plague. And a friend caught some wonderful blue corn tortilla parasite. And the interstate highway was two narrow strips of asphalt (one for each pair of wheels) separated by a few feet of grass. And the phone numbers were four digits long. ___ 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] F*watch
If you want to add wi-fi to a project, take a look at the ESP8266 wifi system-on-a chip. It has a wifi transceiver and a 32 bit processor on a single chip. People have been getting 300 meter range with a PCB antenna. There is now a GCC compiler for it... lots of work going on here: esp8266.com It loads the firmware from a serial EEPROM. There are small PCBs available for around $5 on Ebay. Standard firmware implements serial to wi-fi. ___ 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] TM500/TM5000/HP-5370 Extender cables and cards
I suspect that 90% of the work could be done with a single kit. That will get one card out of the chassis. But, there are always those annoying problems where getting two cards out can make life a little easier. With two kits you could also hack up the extra 44-pin board to make a smaller board (or boards) for getting the odd-ball cards out (if you can find the required edge connectors). So far, I've only needed to do a single card... I suspect most TM500 people will want two cables, but that depends upon what modules you have. Most modules just have one connector. Some of the fancier ones use two. And a very few use three. I even have a custom module that has 4... At first, I didn't think that the TM5000 GPIB extender cable would be all that important, but I have wound up using it several times. -- Hi Mark - do you recommend one 5370 Extender set or two? ___ 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] TM500/TM5000/HP-5370 Extender cables and cards
The TM500/5000 and HP5370 extender kits are now available (actually they were ready a few weeks ago, but I was going to be out of town and did not want to leave people hanging).Prices are:HP5370 extender card kit - has 2 x 36 pin extenders and 1 x 44 pin extender. $30 setTektronix TM500/TM5000 module extender cable kit - $20Tektronix TM5000 GPIB extender cable (assembled) $20US shipping is $6 for any number of kits. International shipping is $15 for any number of kits. If you need international tracking they must go registered mail which adds another $15 (and slows down the mail) or express mail which is stupid expensive. All kits include everything you need to get going except solder and basic tools.Email me for my Paypal address.The HP5370 extenders are 5 inches long.The TM500 kits include a pair of 17 40 pin IDE ribbon cables. You may want to use your own, longer cables. The TM5000 GPIB cable is around 28 long.Remember that some TM500/5000 modules require 2 or 3 extender cables... I even have one that needs 4, but it is a one-off custom design. ___ 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] Sun Outage
The sun can have some effects on GPS signals, particularly when doing ultra-precisiony sorts of things. Version 4 of Lady Heather calculates the sun (and moon) positions (and moon phase) and can display them as part of the satellite position map (and analog watch display). This feature was added at the request of a few people that are/were investigating the effects of the sun on GPS signals. ___ 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] Thunderbolt Rollover
Version 4 of Lady Heather(not yet released) has rollover compensation built in. If the detected date is less than the current system date it adds 1024 weeks to the Tbolt date/time by default. You can also specify an alternate rollover offset or disable rollover compensation. ___ 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] Finally got around to modifying my Fluke 845ab with LED's
No web page, but a little description here. It has changed quite a bit from the original description. Now uses TAOS color sensors. Suppors Melexis IR thermometer chips. Has 16 bit A/Ds. Processor is an ATMEGA 1284. The control program is based on Lady Heather. Besides LEDs it can also charge/discharge/analyze batteries, measure power converter/supply efficiency, etc http://budgetlightforum.com/node/12296 CIrcuit board: http://img69.imageshack.us/img69/3782/luxor.png Sphere in action: http://img515.imageshack.us/img515/4288/spherew.jpg BTW, the PWM sensor is a silicon phototransistor with not much blue light sensitivity... - Do you have a web page on the LED analyzer/integrating sphere? ___ 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] Finally got around to modifying my Fluke 845ab with LED's
Whoops... that last message should have gone to volt-nuts... ___ 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] Need help with transformer core
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) off of Ebay for as little as a dollar each... including shipping from Old Cathay. I usually buy them 10 or 20 at a time. ___ 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] Need help with transformer core
There are actually quite a few makers of what you seek... EMCO H40P will do 3.75 mA at up to 4000V... voltage selected by a 0..5V input. Also check out PPM's offerings... http://www.ppmpower.co.uk/high_voltage_dc_dc_converters/ And UltraVolt's 4AA series: http://www.ultravolt.com/uv_docs/AASeriesDS.pdf - but A 24VDC input 3700VDC output at 4ma does not seem to be available! ___ 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] HP5370 extender cards?
It usually takes 2-3 weeks to get boards back once sent to the fab (in China). Supposedly the boards that I am having them do for another project should be here today and I can verify their quality. I also laid out a 20 pin extender to connect the input board to the front panel, but I don't think those would be too useful. You can extend the other side of the input board/front panel using a 36 pin extender. A while back I had the idea of doing a replacement board for the custom HP input comparator chips that fry is you overload the 5370 inputs. Need to start looking at what that would take... there are two different versions of that chip/input board. The replacement could be for just the chip or the complete input board. -- Approx how long should they be ready to ship after you decide to proceed with the order? ___ 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] HP5370 extender cards?
Yes, can ship world wide. Not sure what the postage will be, but should not be too bad. I'm leaning towards a 3 card set as the standard. Two of the 36 pin extenders and one of the 44 pin. There are a couple of other misc boards in the machine with different pin counts (oscillator, oscillator power, oscillator buffer) but those three should be able to handle most of the work. If you really needed to extend the 30 pin oscillator or buffer cards, you could hack up a 36 pin card. I got my other projects' boards in from China today. They look good. Now to get the TM500 and 5370 boards on order. ___ 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] WWVB for Time Nuts
No, that is exactly what they usually do. They want to keep you in the dark and guessing as much as possible. I once had a guy claim a product we built infringed his patent. He had a memorable name. Turns out I remember talking to him after he had bought one of our products a couple of years earlier... the exact product he claimed we were infringing. Found a copy of his invoice... dated months before his patent dates. Great fun was had when that little fact was pointed out to the patent office... patent fraud charges were filed. Another time a guy also claimed we were infringing his patent. Our product also pre-dated his patent, but rather than fight it we convinced him to license us his bogus patent for a dollar... and let him go after our competitors with his patent. not just you are infringing on our patent. you need to haltproduction immediately and can't resume until you have properly guessed how you are infringing and stop, or, pay us a crapload of money ___ 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] HP5370 extender cards?
Well, after doing my TM500 extender cables, I was thinking of doing an extender board for the HP5370 boards. It would take two 36 pin extender cards to extend a card out of the card cage (the count chain board has a different connector spacing than the other boards so splitting the extender onto two boards lets one be able to extend the count chain board also). The board at the front of the unit has a different pin-count connector than the other boards and may not warrant doing its own extender card. Is there any interest out there in HP5370 extender cards? Depending upon quantity, cost should be in the $15 to $20 range. ___ 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] HP5370 extender cards?
Boards would come with the edge connector. I just finished laying out 36 pin and 44 pin 0.156 extenders. They are 125mm tall (HP5370 boards are 100 mm tall). I could go to 150 mm tall if that would help them to be useful with other equipment. You could hack up the boards for use with connectors with fewer pins. How about a source for connectors? ___ 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] HP3458A calibration memory backup
I did some more playing around with the 3458A memory dumper this weekend. I built up another system using a different computer/cables/software/GPIB interface (one I built using an AVR chip that emulates the Prologix RS-232/USB converter). I noticed than a couple of dumps of the CAL ram (out of maybe two dozen runs) had one byte near the end of the RAM (in that same string of 01 bytes) sometimes read as 00 or 05. This was with a different 3458A and it has been continuously powered for a couple of days. Perhaps the memory chip is not enabled at those addresses and it is reading a floating bus? ___ 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] Tektronix TM500 extender cable kit
I got in my prototype extender cable boards from OSHPARK.COM today. OSHPARK only builds boards in multiples of 3 and I only ordered three boards so could only build one cable. It seems to work very well. I tested it with several different TM500 and TM5000 modules (using another set of cables I have with the dual and triple wide modules) and they all worked fine... including some real power hogs like a Ball Aerospace rubidium oscillator. I have a bunch of circuit boards of a different design on the way from a new (for me) Chinese vendor. If they look good I'll order a couple hundred of the extender boards (it takes two boards to make one cable). I have also pimped out the original extender board silkscreen and added an LED to the +11.5V supply. ___ 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] Tektronix TM500 extender cable ki
I have seen the Jamma kit (I will be using their edge connectors) and John's design. Their main problem is the hassle of wiring up 56 individual wires. Also that tends to be not all that reliable... wires tend to break at the solder joints. The board that I laid out has two 40 pin ribbon cable box headers on it (the layout is compatible with IDE headers that have pin 20 removed or blocked). All of the power pins on the TM500 bus use two conductors (plus Tek doubled or quadrupled most of the power pins). The other pins are signal level pin that don't carry much current. A single 28 ga ribbon wire of the appropriate length should be able to do an amp or so. There should not be any major problems running most modules. The same board is used on the mainframe side and module side of the cable (photo attached). A nice thing about the design is you can very easily replace the cables with new ones of any desired length. ___ 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] Tektronix TM500 extender cable kit
Yes, all 56 pins are extended, including the PWR pin unique to the 5000 series (it is a power good/power-on reset sort of signal).Several of the TM500 modules are also double-wides and need two extender cables. I have not done an extender for the GPIB connector, but that would be easy to build. When I've needed to extend the GPIB bus in the past, I just used a cable that had a 20 pin ribbon cable edge card connector on it and a standard IDC header on the other end that plugged into the mainframe motherboard where the GPIB connectors connected (the mainfame I was using had the GPIB connector bus built out of IDC ribbon cable/connectors. - Am I right in thinking that two of these connector/cables would give the full facilities on the 5000 series units. ___ 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] Tektronix TM500 extender cable kit
Well, just for grins, I did a small board for extending the TM5000 GPIB connector. I remember that the last time I extended the GPIB bus by hooking a ribbon cable to the TM5000 mainframe motherboard it was a bit of a hassle to get to. These should make life easier... ___ 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] Tektronix TM500 extender cable kit
I just finished laying out a small circuit board for building an extender cable for the Tek TM500 series mainfames / modules. Prototypes are off being fab'd at OSHPARK. Should be here in a couple of weeks. It uses two 39/40 pin ribbon cables (all the power pins use two wires)... e.g. IDE/PATA disk drive cables. I know LOTs of us have and use these venerable old workhorse machines. They are well documented and easily maintained (particularly if you have extender cables). Is there any interest in purchasing a kit of all parts to build an extender cable. With a moderate amount of interest the price looks like it would be around $20 per kit plus shipping (probably around $6 for shipping in the US for as many that can be stuffed in a small priority mail flat rate box... most serious TM500 users will want 2 cables for the wide modules). Kit cables would be 18-19 long. TM500 extender cables have been selling on Ebay for $150-$350! ___ 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] Tektronix TM500 extender cable kit
I think a cable made from ribbon cable edge connectors would be the easiest/cheapest way to extend the GPIB connector. Have you thought about making extensions for the smaller connector used to distribute GPIB in the 5000 series? ___ 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] GPS III
I have purchased about a dozen of these receivers (mostly the RS-232 version for $1 more). Reyax ships very fast. I get them in about 1 week. They work well, and are based upon the Ublox MAX-7C. They output independent GPS and Glonass NMEA messages and don't appear to merge the two systems in their navigation solutions. I have not done any testing of the 1PPS signal (which is brought out to the connector). -- On eBay the RNY25A1 receiver module sells for $15 ___ 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] GPS III
They seem to do pretty well. I have mine in devices sitting on my kitchen floor. It is downstairs in a stucco over wire mesh house. Nearest window/door is 20 feet away... and it is shaded by a stainless steel covered bridge to the guest house. Also lots of stainless in the kitchen... they are sandwiched in an isle between a pair large SubZero fridge/freezers one one side og the isle and a center island clad in stainless.I can take them a few minutes to acquire down there and they occasionally lose lock (mainly late at night when the geometry/coverage is bad). I think the NEO-6M receivers may be a tiny bit better about acquiring signals. - How good is the built-in antenna? Do they work well in doors away from windows? ___ 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] new clock
An oscillator can take many weeks to settle in after being powered off / shipped / abused / looked at cross-eyed / etc. It typically takes a Thunderbolt a month or two to settle down after being shipped from China. ___ 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] Temperature sensor
You don't want to do freezing point tests with gallium... it really likes to supercool without freezing. A gallium triple point cell is the way to go. Good reading here: http://www.nist.gov/calibrations/upload/met15-79.pdf I once built some precision temperature measurement equipment that we calibrated against an ice bath (using purified, degassed, DD water) and boiling water (pressure corrected). The devices were then sent off to one of the national labs where they did calibrations against water and gallium triple points (and who knows what else). Our cheapo calibrations agreed in the millidegree area. Their final calibration polynomial was something like a 23rd order poly... ___ 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] Time in Phone System
Yes, the caller ID data has time in it. There are chips out there that decode caller ID. I signaling format isially is the old Bell 202 modem protocol. The caller ID devices sort of half way answer the phone line when it detects the incoming call and the caller ID info is sent after the first ring. ___ 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] GPSDO standard interface?
Yes I have... I have built several sensor type boards that use an ATMEL chip as the processor. They output data in a TSIP packet format that tricked up versions of Lady Heather can control and monitor. The most complicated one is probably a LED/Battery analyzer device that measures voltages, currents, intensities, color spectrum, etc and can PWM a 90 amp power FET. The TSIP requirements for a GPSDO can be fairly simple. Look in the heathgps.cpp file in the Lady Heather source code to see what messages are important. You don't need to implement all (or even most) of them. The more you implement, the better Lady Heather can control it. Lady Heather basically wants to see the primary and secondary timing messages every second. It uses those messages to trigger requests for other info/status messages... a different message each second. So, start with outputting the primary and secondary timing messages every second.You probably also want to output the lat/lon/alt message. Then add support for other messages that you want to see/control. As far as Windows is concerned... Lady Heather is open source. Feel free to port it to Linux, etc... it should not be too difficult... but many people have said that they would do so, but so far nobody has. If you want to do so, I can send you the code that I have for version 4.0. It has some changes to the plotting code and TSIP parser that make it easier to tweak for different data logging applications (such has my LED analyzer). --- That sounds good but have you figured out how to implement this? ___ 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] GPS puck?
Check out these puppies... $16 with logic level interface, $17 with RS-232 interface. Does GPS and Glonass. Has antenna. Has 1pps outut. Can do 10 Hz updates. I ordered 6 of the RS-232 units and they took about a week to arrive. I have not done anything with the 1PPS output yet. I did lay out a small piggyback circuit board with a DB9 connector and 3.3V regulator so the unit can be powered via a 12V signal on pin 9 of the DB9. http://www.ebay.com/itm/RYN25DI-10Hz-RS232-interface-high-performance-GPS-Glonass-antenna-module-battery-/171340780546?pt=LH_DefaultDomain_0hash=item27e4b4d402 - Slightly OT, but not much, does anyone in the UK (or close) have a GPS puck (mouse, sensor etc.) with serial NMEA output available cheaply? Ideally with RJ11 (6P4C) connector, but I can solder ... ___ 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] GPSDO standard interface?
There are TSIP commands for doing all those things. It should be fairly easy to adapt them to control your hardware and whatever GPS receiver you are using. The nice thing about implementing a TSIP interface is being able to use existing programs like Tboltmon and Lady Heather (over 30,000 lines of code) to monitor and control it. Also NTP knows how to talk TSIP. I am planning on the output of at least position, corrected phase error, DAC value, ambient temperature, and a few other things. I also see a need to read and write the PID gain and damping factors, but that may just have to be a custom tty interface. It may be that I need to have a pass-through mode to give direct access to the receiver for triggering site survey, etc. ___ 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] GPSDO standard interface?
There is no standard interface for GPSDOs, but the Trimble TSIP interface as used by the Thunderbolt/Lady Heather would be an excellent place to start and include. Make the unit smart enough to run unattended, but add enough monitoring commands so Lady Heather, etc can be used to monitor and tweak it... it will save you a lot of work and Lady Heather's graphing and logging features provide great insights into its operation, performance, and quirks. ___ 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] FE5680 GPS Disciplined Controller Update
Check out the temperature control code in Lady Heather. It uses a nice PID controller algorithm (from Warren Sarkison) to PWM modulate a fan to stabilize the environment around the Tbolt. It can achieve millidegree range stability... I have seen long term RMS values of the temperature plot less than a few micro-degrees. The standard Tbolt oscillator has a rather horrible tempco... I'll post some recommendations/findings about various environmental sensors I tried while I was building my weather/envionmental sensor package. Hint: the MS5611 pressure sensor chip is very nice. Has 24 bit ADCs for the pressure and temperature readings and produces very stable readings with a 100 Hz update rate. -- However it is disappointing that no one has stepped up to tackle the temperature problem. ___ 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] FE5680 GPS Disciplined Controller
Maybe... maybe not. Some of the Rb's store the tuning word in the processor EEPROM and those have a rather limited number of write cycles. You can change the DDS tuning words almost as many times per minute or per second as you wish to achieve the desired average accuracy. ___ 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] Virgin time nutter fell at the first M12+ hurdle
I have had great difficulty getting various MAX3232's to work reliably on 3 .. 3.6V.The datasheet shows the capacitor values you need to use for various voltage ranges... but no joy. The DC-DC converter does not produce the proper output voltages. Check the V- and V+ nodes for around +/- 6V Oddly, MAX232A's seem to work just fine on 3.3V... I usually use 0.47 uF caps on them. I don't use the non -A versions for the MAX232. ___ 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] Boeing 787 GPS reception trouble
I build and fly large model rockets. Many use carbon fiber in their construction. I can tell you that carbon fiber does conduct electricity... not quite as well as pure metals, but pretty darn good... and the conduction is anisotropic (better conduction along the fibers than across their diameter... and the same for thermal conductivity). And that it makes a GREAT RF shield. Most of my rockets have tracking transmitters in them... most at around 220 Mhz A single layer of 5 oz carbon cloth around a phenolic body tube can almost totally block the tracking signal of a transmitter that has a 20+ mile open-air range. Once inside the carbon wrapped airframe, it has a range of a couple hundred feet. You get the tracking signal only when the rocket separates and the tracking transmitter is extracted from the airframe. An interesting observation is that putting the transmitter in an aluminum airframe has little effect on its range.It seems that that the semi-condcutive properties of the carbon fiber is responsible for its RF properties. ___ 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] Toy radiolocation and LORAN envelope
I should mention that the circuit that I attached in the previous post does not output at 49.152 MHz The output is the third (or fifth?) harmonic of the crystal frequency... ___ 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] Weather/units question for European members
I ran across this very issue when trying to calibrate my barometer chip against the NWS station located less than two miles away. Their numbers for millibars and inches of mercury do not agree. I sent them an email and asked what was going on. They said their instruments read out in millibars (to three decimal places) The reported value is converted to sea level pressure and reported to two decimal places. They are also converted to inches of mercury for their reports. Only problem is their conversion constant is NOT the proper value. They consistently report around 0.02 too high. I reported this back to them, but have received no further responses. Note that the conversion between true pressure readings and sea level pressure involves an equation with about a fifth power/root (depending upon the direction of the conversion) so it can be quite sensitive to true chip calibration. The pressure chip that I am using (MP5611) is factory calibrated and has calibration constants stored on-chip (the Bosch BMP085 and BMP180 chips also do this), but the soldering process can affect the chip so you need to do some final calibration. The MP5611 can detect the air pressure change seen by raising the chip less than 6 inches... Relevance of temperature/humidity/pressure sensors to time-nuttery? We all know the comparatively massive effects of temperature on our equipment. But humidity and air pressure also affect them in many subtle and not-so-subtle ways. I'll post some recommendations/observations on various sensor chips in a while. - One funny thing about weather measurements is that the data that NOAA reports is not what it would seem. The standard ASOS data (which is what NOAA reports in its local current conditions) includes barometric pressure in inches of mercury and in hectoPascals. It turns out that neither is the actual barometric pressure. ___ 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] Weather/units question for European members
I am building a weather sensor that includes a ultrasonic anemometer to measure wind speed, direction, and air temperature. It uses 4 cheap ($1 each) HC-SR04 ultrasonic rangefinder modules that output a pulse width proportional to the time of flight of the sound signal (topic is time nut related since it simultaneously measures the speed of sound in 4 directions to a pretty good accuracy/resolution using a cheap-ass microprocessor - ATMEGA328 (like and Arduino)... and does so without using any counter-timer channels). Now the question... I would like it to be able to output data in imperial or metric units. In what units is the typical wind speed reported (meters/sec, km/hour, ?). Also air pressure (millibars/hectopascals/pascals/?). ___ 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] Weather/units question for European members
The project sounds like a fun hack -- I would be curious as to the resolution you achieve with these modules.--- The best description on the net about building a sonic anemometer is one by Hardy Lau:http://www.technik.dhbw-ravensburg.de/~lau/ultrasonic-anemometer.html I have also built one that I call the Cheap Ass Sonic Anemometer It is part of a portable weather sensor for use at launches of large model rockets (some reach over 100,000 feet). It is built out of very inexpensive, off-the-shelf components. The only wiring involved is hooking power, ground, clock, and data lines to small off-the-shelf circuit boards (mostly from China off of Ebay). I did lay out a custom circuit board so I don't even have to do that. A commercial sonic anememeter can set you back $5000. It uses 4 HC-SR04 ultrasonic distance sensors ($1 each!) as the wind sensors. These are small modules that you drive with a 10 microsecond ping signal and they output a pulse width dependent upon the distance to an object. I use two modules facing each other on each axis and fire them in pairs. Instead of picking up an echo, they receive the ping from the opposite module. You can fire them around 30 times per second. I use an $5 ATMEGA328 chip based CPU board (you could use an Arduino) to measure the pulses and calculate the wind direction, speed, and temperature. I was originally using a more powerful processor (ATMEGA128) that has two 16 bit counters with input capture capability to measure the pulses with 65 nanosecond resolution, but to make the device more accessible for other people to build, I switched to the ATMEGA328 and time the pulses in software to around 1 microsecond resolution. I was measuring all four directions at the same time, but started seeing some cross-axis interference with some of the SR04 modules and switched to simultaneously measuring the N-S and S-N times followed 3 milliseconds later by the E-W and W-E times. Surprisingly the downgraded pulse measurement capability did not affect the results to any significant degree. The structure is built out of 1 inch inside diameter PVC plumbing pipe and couplers/caps... around $5 total. The ultrasonic sensors are spaced around 0.65 meters. The D/L ratio is around 20. The larger the D/L ratio, the smaller the errors caused by the structure interfering with wind flow. The device also contains a 10 degree-of-freedom inertial measurement unit board ($11) that is used as a tilt compensated magnetic compass and highly accurate barometer. It also has a DHT-22 humidity sensor ($5) and compensates the sound measurements for humidity and air pressure (which can be quite high a high temperatures and humidity levels). With the compass measurements you can deploy the sensor in any orientation and it adjusts the wind readings for however it is aligned. Also, you can buy the IMU boards for less than the price of the pressure sensor alone! The software auto-detects and supports 5 different pressure sensors, 4 different accelerometers, and the popular HMC5883 magnetometer chip (also used in the popular ST LSM303 integrated magnetometer/accelerometer. It also has an AS3935 based lightning sensor board ($20)... but they don't seem to work very well. I live next to a golf course that has an elaborate lightning warning system and the AS3935 has never triggered even though the golf course waring sirens have gone off several times. It also has a UV light sensor ($13 from Sparkfun) for reporting a UV index. I get temperature measurements with around 0.5 degree F accuracy and 0.25 F noise (averaging readings over 3 seconds). I am still characterizing the wind speed/direction measurements, but they seem to agree quite well with a cup/vane anemometer... basically if your temperature results are accurate your wind measurements will be spot on. The nice thing about measuring temperature via sonic measurements is that the measurements are unaffected by solar heating of the apparatus... it does not need to be in the shade. Also ___ 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] The Problem with Time Timezones - Computerphile
Ahh, but with Lady Heather you can specify the time zone offset (down to the second) and the when the daylight savings time switchovers occur. And from experience, I can tell you that the code to do it is a royal pain in the ass... not all that hard to do, but a pain to test. -- That is the problem. Even if someone gives you this code free and it works, then some years from now some country will change the date when they switch over to daylight savings or they even change a time zone offset. ___ 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] The Problem with Time Timezones - Computerphile
There is code in Lady Heather that does all this (independent of operating system settings). Plus code for calculating and displaying dates in numerous calendars. Also calculating various holidays, sun and moon position/phases, . etc. Hint if you want to write calendarish code... it helps to have good Julian and Gregorian date/time conversion routines handy... ___ 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] New timing receivers?
I have done a PCB that has connectors/mounting holes for the Adafruit, Crius CN06 (uBlox Neo 6M), and Resolution-T and -SMD receivers. It has a DB9, 3.3V regulator, and MAX232A chip. It can drive the 1PPS signal (either polarity) to the CD signal on the DB9. Power to the circuitry can be raw input voltage or regulated from either a 2.1mm barrel connector or pin 9 of the DB9. There is a small prototyping area on one end of the board (includes some pads intended for an Atmel ATTINY85 processor). I can put the board on OSHPARK.COM shared projects if anybody is interested. They wind up costing $30 for three boards. I am waiting for the newest rev of the boards (with the ATTINY85 footprint) to arrive from OSHPARK in a few days. --- I already had something that looked to fit the bill even though not the same size as these micro modules. I have some Trimble Resolution Ts and SMTs ___ 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] Low cost GPS module for 100ns timestamping error
The Neo-6M based module (Crius CN-06) is available from HobbyKing for $20 (sometimes on sale for $16). You do have to add the wire to access the 1PPS signal. In my testing, I prefer it over the Adafruit Ultimate GPS. The Neo-6M seemed to a a little more sensitive (could get reliable lock and tracking sitting on the floor of a 2 story stucco house (stucco over wire mesh) away from any windows and did not have issues with reporting fixes of a rather stationary antenna - the Adafruit module would fake a fixed position if it was not moving). I did a little testing of the 1PPS output and it seemed to be quite good. My application was mainly driven by the desire to calculate the range and bearing between two units spaced 100 feet to a couple of miles (using an Xbee radio link). I could move a unit in a circle a couple of feet radius around another one and get good range/bearing info... not too shabby for a $20 hockey puck. ___ 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] New timing receivers?
When I was playing with an Adafruit GPS, it appeared that if it thought you were not moving it would go into a pseudo-position-hold mode and the output coords would not change. It took it a while to start outputting new coords when you started moving again. This test was at walking speeds. I had to walk maybe 100 feet before it started sending new coords. I assume it is actually producing fixes, but not changing the output sentences (i.e so that a car stopped at a traffic light does not show it moving randomly around the intersection). ___ 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] Measuring the accurcy of a wrist watch
What are these wrist watches of which you speak? I saw some old geezer wearing some sort of clock bracelet a few years ago. Are they similar? ;-) ___ 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] ARM boards for low-cost GPSDOs
Some of the STM DIscovery boards are less than $10... search mouser.com for STM Discovery ___ 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] First success with very simple, very low cost GPSDO, under $8
Well, where interrupts are involved, NEVER assume something about how the code SHOULD/MIGHT be working. It is easy enough to disable interrupts before accessing the volatile variables and restore them afterwards. This is by far the simplest and most reliable way to do it correctly (no messy message passing/semaphores/smoke signals/etc). unsigned char sreg; // variable to save the processor status register in sreg = SREG; // save current processor status register cli(); // disable interrupts in the status register // access variables here SREG = sreg; // restore original interrupt state ito the processor status register ___ 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] First success with very simple, very low cost GPSDO, under $8
I'm not sure how the Arduino environment handles interrupts, but in C you need to declare any variables altered by an interrupt as volatile so that the compiler optimization routines know not to assume they contain known values. Also any code that accesses them needs to do so with interrupts turned off... otherwise you can wind up with corrupted values. Imagine that the mainline code is accessing a multi-byte variable. The code accesses the lower byte, in comes an interrupt that changes the variable (new low and high bytes, then the interrupt routine returns to the mainline code), and then the mainline code proceeds to access the (now changed) high byte of the variable... the resulting value is a mishmash of the old and new values. ___ 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] new GPSDO kit
Check out the semi-Arduino + OLED LCD that Sparkfun will be selling soon... it's tiny, fairly cheap, and can run on 3.3 to 18 volts. Looks like it will be very useful for a lot of small projects. Unfortunately, the OLED does not appear to have a touch screen. https://www.sparkfun.com/news/1445 I plan on changing out the LCD display to a $4 Nokia cell phone part that does 84x84 pixel graphics. I'd like to have the GPSDO do its own primitive graphs and setup menus without need to be connected to a computer. ___ 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] FEI-5660 Rubidium Oscillator
no, No, NO granite! Granite tends to be rather radioactive (particularly avoid the pink stuff). Any audiofool worth his tin ears can't have no stinkin' alpha/beta/gamma particles mucking with his music! BTW, before I bought my house, I tested all the granite surfaces with my rather nice scintillator. The real estate agents were rather bemused... but when one bought his own house had me give it the once over... he had read up on the subject.. Oh, and I've never seen a fireplace that didn't tick like a mother... --- A precision machined, finely crafted 100 pound block of granite ___ 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] How I got my FE-5680A to lock in Sydney, Australia
What was the timebase for your counter? I suspect that it is off freq and the Rb is not actually making it above 10 MHz. Inverting the Rb is causing a 2G shift in gravity to the Rb crystal probably shifting its freq enough to cause lock. ___ 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] clock and cannon at noon story
Geez, ya' gotta ask? He's a watchmaker... they're all nuttier than aunt Martha's fruitcake... -- The real question is how nutty is the watchmaker? ___ 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] Nortel GPSDO osc age alarm
The OSC age alarm says the oscillator EFC control voltage is getting near to its programmed limit. The DAC alarm says that the EFC dac setting is it is at the limit. I suspect that your oscillator EFC input is bad. I've seen this on a couple of boards. ___ 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] Local Solar Time Clock
I tried that algorithm and it did not seem to agree all that well with more sophisticated ones... This one seems to work better: http://www.astronomycorner.net/games/analemma.c -- See www.leapsecond.com/tools/eot1.c, source code that generates the equation of time and its derivative ___ 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] arduino solar clock
I'm pretty sure the arduino double precision routines are actually single precision... at least they are in the standard AVR ports of GCC. ___ 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] keeping Arduino timekeeping and clock synced up
The EOT code that I linked to (http://www.astronomycorner.net/games/analemma.c) and am using is interesting because it appears to be applicable to other planets. It has parameters like the orbit obliquity/eccentricity/perihelion/year length that can be changed. It also does not make assumptions like the time of perihelion is 12 days past a fixed value of the winter equinox (i.e. Jan 2). A clock routine that I wrote for the ATMEGA2561/ATMEGA128 runs off of a 10Khz interrupt. It does a first-order compensation for crystal drift by occasionally ignoring or duplicating timer tick processing. It can produce very good long-lerm clock performance. I also have had very good results using the DS3231 temperature compensated clock chip. My alarm clock uses a Trimble Res-T GPS backed up by the DS3231... - I've got the Arduino code running that does the EOT ___ 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] Local Solar Time Clock
Lady Heather can display time in LMST/LAST/GMST/GAST I made a version that has an option to just show the date/time in full screen mode for Jim Lux/JPL but never heard back from him. ___ 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] Local Solar Time Clock
http://www.pendulumofmayfair.co.uk/view.asp?pid=272cat=Longcase%20Clocks ___ 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] Local Solar Time Clock
I just added a equation-of-time routine to the next release of Lady Heather. ..It can offset the time display by the Equation of Time. The calculated offset seems to agree rather well (like around 0.01 minutes) with the one on the NOAA website. It could be made a little better, but that would take more than a little work. ___ 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] saving Lady Heather set-up?
Yes, Lady Heather has two ways of loading/changing a configuration. You can put a heather.cfg file in your Lady Heather directory. This file should contain any command line parameters that you want to use... one per line with the '/' in the first column. Use heather /? (or ? from the keyboard) for a list of command line options. At the end of that help dialog screen it will tell you what your heather directory is. Also see the comments at the start of the heather.cpp source code file... that is where what passes for program documentation is... You can also make keyboard script files that when read in with the /r=???.scr command line option or the 'R' keyboard command will be read and the text in the file will act just like you typed it from the keyboard (with a few extensions that are documented in the comments at the start of the hearher.cpp source code file). There is not a way to have heather automatically write a .SCR file that will re-create any changes to the configuration that you may have made... your have to create the script file manually. Script files can be nested up to five levels deep. ___ 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] saving Lady Heather set-up?
Oh, and there is an another way to configure the program if you can do it with command line options... edit the startup command line in the program PREFERENCES (right click on the Heather icon). You can also do this to automatically load your desired keyboard script file or a different .CFG file (the /R command or 'R keyboard command can load .CFG files (and a whole lot more)) ___ 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] WWV/WWVH audio simulator?
That's usually caused by the expulsion of vast quantities of hot air ;-) I once hooked an audio spectrum analyzer to an FM radio. You could almost always see 15734 Hz and/or 15625 Hz tones in all the songs that they played. There were quite a few songs that obviously had parts recorded in the US and others in Europe. Not a good idea to put TV monitors in a recording studio booth. Maybe things have improved since the advent of LCD monitors... when the guy at the station talks, there are strong components below 100Hz ___ 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] HP 5065A serial number list
1420A00658 ___ 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] Computing GPS Distance Error in Time
I'm not using any special surveying software, just some code that I wrote. The controller box and remote box both have GPS units in them. The controller periodically requests the remote unit's position and just calculates the vector distance/bearing between the two units. The application was intended to work with the boxes spaced 50-5000 feet apart. I was rather surprised how well they worked very close together. The next step is to add a magnetic compass module to the controller box so that it can draw a map of the remote units in relation to the orientation of the controller box. -- What type of real-time surveying software are you using? I'm looking for surveying/plotting software for Linux to keep a close on the timing stability of my Adafruit. ___ 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] Computing GPS Distance Error in Time
I am only interested in the relative distance and bearing between the control and remote boxes. What I am doing amounts to differential GPS. The receivers are pretty much influenced by the same atmospheric, etc distortions that affect absolute positioning accuracy. When the two sets of coordinates are subtracted, those common mode errors get removed. ___ 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] Computing GPS Distance Error in Time
Lady Heather has the ability to plot position fixes. If you are handy with programming you could insert some sort of NEMA to TSIP converter between the AdaFruit and a computer running Lady Heather. You would need to emulate a few of the TSIP packet (like primary timing, secondary timing, and position). ___ 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] Computing GPS Distance Error in Time
I was using the Adafruit GPS receivers to calculate the bearing and distance between two boxes that had radio tranceivers in them. The control box polls the remote box position and does simple trig on the difference between the GPS coordinates. I noticed that the Adafruit GPS seems to go into some kind of funky position hold mode if thinks that it is not moving (or is actually moving very slowly)... the GPS coordinates stop updating until the box moves some distance. I got much better results using a CN06 GPS module that is based upon the Ublox Neo-6M. You need to solder a wire to the Neo module to access its PPS output. HobbyKing sells them for cheap... also lots of sellers on Ebay. I could put one box on the ground, and move the other one around it only a couple of feet away. It gave remarkably good results considering the boxes were much closer than the average GPS error... it is basically a differential GPS application. Also, the processor is an AVR running single precision floats. I laid out a breakout board that can take the Adafruit, CN06, or Trimble Resolution T GPS boards and convert the TTL/CMOS levels to true RS-232 levels via a MAX3232 chip to a DE-9 connector. PPS polarity is jumperable. ___ 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] beta tester needed: hp5370 processor replacement project
At the size that it is, OSH Park boards will be a bit pricey. I would look at SeeedStudio's Fusion service. 50 4x6 boards with ENIG gold finish would be less than $200. Both places do very good work... http://www.seeedstudio.com/service/index.php?r=site/pcbService ___ 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] Need a schematic of Trimble 2003 era Thunderbolt RX
Buy a Thuderbolt and send it to these guys... they will reverse engineer it for dirt cheap... and they do a good job... price is $20 hour and if you let them re-publish the work, it costs less. bomarc.org ___ 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] Space mission comes to an end becuase of a computer time tagging problem
And my favorites: Nickel-Hyrdogen cells and their silvery cousins. You have to work REALLY hard to kill them. --- for rechargeable? NiCd (in the past) Lithium Ion (now) ___ 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] Space mission comes to an end becuase of a computer time tagging problem
No, I'm talking about nickel/gaseous hydrogen cells. Basically they can't be overcharged/overdischarged/frozen to death. State of charge can be determined by a pressure reading. Can be cycled a zillion times. -- And my favorites: Nickel-Hyrdogen cells and their silvery cousins. You have to work REALLY hard to kill them. Yes, forgot the NiMH too.. although they self discharge ___ 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] Lightning Strike Site, Latency of AS3935 IRQ output
The AS3935 chip has a DSP on it that is doing a lot of statistical analysis. It only draws a few microamps, so it's gotta be slow. I'd be VERY surprised if the detection to output timing was even slightly deterministic. ___ 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] TBolt temperature sensor
Lady Heather does not truncate the display of any values. Generally, it It reports all values to the resolution that the device sends... garbage in, garbage out. -- but the program you're using (LH?) apparently truncates the display ___ 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] New NTBW50AA
Geee, what's so hard to understand? As I said several times before, the firmware on these units can only read the temperature sensor to 1 degree increments (there is a 0.25C offset). The temperature jumping around is the temperature crossing the 1 degree C quantization threshold. Most of the firmwares do a running average of the last 10 readings, so you can see some intermediate values. Also, due to a bug in the temperature sensor chip, you can see occasional spikes in the temperature readings. These show up as a step impulse on the leading edge followed a decay over around 10 seconds. All of these temperature sensor issues have been discussed ad nauseum here before. Search the archives... ___ 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] New NTBW50AA
Lady Heather just reports the data the the unit sends, so the precision that it sends it. Garbage in, garbage out... When the program is down-scaling a plot in time, it just skips data points unless display filtering is on (F D command). Then it forward averages the next *n* data points for each plotted pixel. Oh, and those multiple ADEV curves on the plot you saw were due to the way the program plots data. The plot area is only erased and redrawn when the plot scrolls to the left. If you have the view interval set to 4 hours and only three hours of data have come in, the plot never scrolls. The ADEV curves are plotted as each new point is calculated and are drawn on the screen without erasing the old plots if the plot is not scrolling. This lets you see how the ADEV values develop as more data comes in. ___ 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] New NTBW50AA
Again, THE TEMPERATURE SENSOR IS NOT BROKEN!! The firmware in some of these units (those from NTPX modules) does NOT read the temperature sensor in high-res mode. -- Your temperature plots look like mine. I suspect the other unit has a broken temperature detection chip. I've seen that happen on TBolts. ___ 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] Lightning Strike Site
A cute little lightning detector based upon the AS3935 lightning detector chip: http://www.embeddedadventures.com/as3935_lightning_sensor_module_mod-1016.html ___ 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] Lightning Strike Site (Jim Lux)
The AS3935 has an INT output pin that signals a detection. You could monitor that. The AS3935 is based upon an internal DSP processing the receiver output. No telling how long between when the strike occurs and when INT is activated. ___ 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] New NTBW50AA
Look at the comments at the start of the heather.cpp in your Lady Heather installation directory for what there is of ducumentation. Your temperature readings are bouncing around because the temperature sensor is only providing readings quantized to 1 degree C. This is usually due to the GPSDO firmware not being compatible with an undocumented change Dallas Semi made to later revs of their temp sensor chips. NTPX series GPSDO's don't do high res readings even with the earlier rev temp sensor chips. ___ 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] NTP/1-PPS/RS232 question
As I mentioned earlier, the RS-232 interface board that I built is for a non-NTP/non-Time-Nuts project. But, if I can make it useful in those applications, great. I am not going to add any parts to the board for them. That said, the MAX3232 chip has an extra RS-232 receiver on it. I can use it as an inverter and supply either polarity 1PPS signal to the RS-232 connector. It does add up to 300 nS delay to the 1PPS signal. I also added a bunch of 0.1 spaced feedthroughs to the board (under where the GPS modules would sit) as a prototyping area. I tried my application with two of the CN06 receivers. It calculates the range and bearing between them. With the boxes only a couple feet apart, I was typically calculating 2-5 foot distances with a pretty reliable bearing indication. That error is at the limit of what single-precision math can deliver (processor is an AVR chip). Those are pretty slick little GPS receiver modules for 22 bucks... ___ 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] New NTBW50AA
It is reporting temperature just fine. It probably has the new revision temperature sensor chip that the firmware does not read the high res temperature properly. Also, one version of those Nortel units (don't remember which one) doesn't do high res temp readings even with the old rev temp chip. The plots in Lady Heather default to auto-scaling and auto-centering with each update. That can cause the plots to appear to jump around as new data come in. And the F11 full screen mode toggle is known to not work with many monitor/window size combinations. The Nortel units don't save the oscillator damping/gain/time constant settings in EEPROM (at least with any of the documented commands). ___ 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] New NTBW50AA
The green trace is the oscillator EFC control voltage. It will drift quite a bit for the next couple of months of continuous usage as the oscillator ages in. It should settle down after that, but will always be drifting. If it didn't drift there would be no need for GPS disciplining... ___ 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] NTP/1-PPS/RS232 question
I got in those Adafruit GPS boards. They are a very nice little GPS. VERY sensitive. I could get good lock indoors on my (windowless) kitchen floor. The house is 2 story, stucco with wire mesh in the stucco. I could also get lock in a restaurant that had a tin roof. We were far from any windows. The 1PPS signal is normally low and pulses high for 100 milliseconds. The RS-232 adapter board that I built feeds this into an RS-232 transmitter chip (MAX3232), so on the interface connector CD will be at +V and pulse down to -V. Is this what stock NTP likes? Also, I laid out the adapter board so it an accommodate a Trimble Resolution T or a Crius CN06 receiver. The Crius receiver uses a U-Blox NEO-6M receiver. They can be had for around $22 at HobbyKing. They seem to perform even better than the AdaFruit module. It looks like you will need to bodge a wire onto the TIMEPULSE pin to use it for 1PPS. ___ 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] Speaking of 5370s
The slide switches on the 5370's use gold plated springs that slide on a PC board. They are located such that the fan fills them with dust and dirt. Failures are very common, but easy to fix. You need to disassemble the switch board and clean everything. ___ 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] NTP/1-PPS/RS232 question
The board is for another project. It requires real RS-232 levels. There is a MAX3232 chip on it. Since the GPS has a 1PPS output, I figured that I might as well bring it out. There is no documentation on the pulse width or polarity... it is what it is... I'm probably hooking it straight to the '232 chip without any massaging. There is also one more available RS232 input pin on the chip. Any preferences for RTS or DTR? There is a jumper for powering the board from the RI pin (pin 9) of the RS-232 connector. - Yes, this is right. But watch the polarity. It is easy to get it wrong. In RS-232 the controls pins are different from the data pins. ___ 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] NTP/1-PPS/RS232 question
I am building a board to convert the output of the Adafruit Ultimate GPS module to RS-232. The GPS has a 1-PPS output. What is the preferred com port pin for feeding 1-PPS into NTP via an RS-232 connector? ___ 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] Warped back to 1993
According to the Thunderbolt manual on July 30, 2017 Tbolts will experience a rollover error. In version 4 of Lady Heather (being developed), I have added a rollover compensation mechanism. If the GPS year is less than the OS year, 1024 weeks is added to the GPS time until the year catches up. Or you can manually specify a rollover offset or disable the feature. ___ 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] Rb video
I also use a blinking status LED controlled by an ATTINY13 AVR chip. It also reads a temperature sensor and controls a PWM'ed fan. The LED blinks out the temperature. BTW, the guy made a lot of bad decisions in his build. FOr instance, he should have brought out the Rb frequency/PPS signals to BNC connectors and patched them externally into the input BNC's. That way he could use any unused amplifier channels for other things. --- If you want to get fancy, you can run a speed controlled fan on the heat sink to regulate the temperature. You still want to pick a temp that's as low as you can practically get it for your control point. ___ 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 Nortel GPSTM Boards
In Lady Hather, set the elevation mask to a low value, clear the signal level data (S A C), let the unit run for a day or so, then do the oscillator autotune (A). This will set the elevation mask to a level that matches what your antenna can see. Or you can check the elevation plot (S A E) and see where the tick mark shows the signal level dropping off and enter that value manually. ___ 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] Low cost GPS for model aircraft
It would now pretty much be illegal in Texas. Our Wise Legislature has pretty much banned aerial photography unless you have the written permission of everybody in the images and landowners of all properties. Definition of aerial photos? Apparently anything taken from more than 6 feet off the ground. Tall person? Tough luck, get on your knees to snap your photos... -- For a very low cost Ready To Fly quad copter that includes a TV camera see: http://www.prc68.com/I/DCpmMotors.html#Heli-Max ___ 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] HP 10811 update
2N6429... $1 each: http://www.talonix.com/shop/item.aspx?itemid=3522 ___ 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] Nortel Trimble thunderbolt
Most likely the cable to that front panel board is connected wrong. The people that laid out the boards messed up the keying. Connecting it the obvious/marked way won't work. Use RED wire to key mark on the front panel, RED wire to other end on the main board. Lady Heather uses 9600,8,N,1 ___ 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] GPS position survey
Earth circumference is around 25,000 miles - 132E6 feet. 24 bit mantissa (23 bits plus sign) gives a resolution in this application of around 15.7 feet since negative measurements don't apply. --- Oh... 24 bit mantissa should give 1.25 m resolution if my headcounting is about right ___ 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] GPS position survey
The 48-hour precision survey in Lady Heather uses a statistical weighted median filter to arrive at its final location instead of a simple average of fixes. It processes data of one minute, hour, and overlapping 24 hour intervals to calculate the final position. It can produce a location that is 3-10 times better than simple averaging of the fixes. A further complication is storing the precise location into the receiver. The Tbolt firmware only lets one write the location using single precision floating point numbers (24 bit mantissa). This is well below the desired resolution of the position. Lady Heather gets around this by limitation by doing a royal kludge. Once the precise position has been calculated, it issues single point survey commands to the receiver until one just happens to lie within one foot of the calculated position. ___ 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] Common-View GPS Network
Nope, been there, tried that. Supposedly Trimble had a firmware option for doing/reporting proper carrier phase stuff, but I have never seen a Tbolt with it. --- I don't know if the Trimble TBolt or Res-t give out enough information to generate RINEX ___ 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] Windows serial port error reporting question
I have been working a version 4.0 of Lady Heather. One thing that I would like to implement is better error checking on the serial data port... parity/framing/overrun errors. I haven't been able to find much valid info on how to coax this info out of Windows... Does anybody know how? ___ 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] Connectors
Another nifty product from 3M is their cold shrink tubing. It is a rubber tube stretched over a peel-able spiral core. You insert the tube over the cable/connector and peel out the core. The rubber shrinks down over the cable and forms a tight seal. It is typically used on buried cables. I use it to repair old printer platens like in the HP9100 calculator and Tektronix TDR thermal printers that have turned into goo. ___ 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] NTGS50AA Power supply
I looked into the 1PPS/2PPS issue on these Nortel units when I added support for them into Lady Heather. They do not appear to respond to the commands for changing to 1PPS. Also, they do not appear to save the oscillator disciplining parameters into EEPROM (at least using any of the documented commands) ___ 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] Low noise power supplies?
A123 20Ah LiFePO4 cells have an internal resistance in the milliohm range. Their M1 26650 format cells are around 8 milliohms. Most high capacity (3000 mAh) 18650 style lithium cells are around 10-15 milliohms. ___ 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] any unheated Vref better than LT1021-7 (at 7 ppm/khr typ.) ?
Take a close look at the photos of Malones nice little voltage reference boards (http://www.voltagestandard.com/Home_Page_JO2U.html). The voltage reference chip is mounted on an isolated peninsula of PC board material to help isolate it from stress due to environmental changes. If the humidity effect is strictly from mechanical stress on the die as the plastic encapsulant swells or shrinks, would a part in a metal can then be immune from this effect, even if it was non-hermetic? ___ 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.
