Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

In message , "Dr. David Kirkby (Kirkby Microwave Ltd)" writes: >I can't find it now, but I know someone said thermocouples are obsolete. I >spoke to a friend tonight who services industrial boilders. He said >thermocouples are far from obsolesce, at temperatures of a few hundred deg >C,

[time-nuts] Lucent RFTG-u REF-0 Standalone Operation (Dan Watson work)

Starting in August 2015, Dan Watson (Sync Channel Blog) started a project to develop a GPS board to "plug into" the Lucent KS-24361, RTFG-u REF-0 for standalone operation (without the REF-1 module) http://syncchannel.blogspot.com/2015/08/standalone-operation-of-lucent-ks-24361.html By October, h

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

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

Re: [time-nuts] Free to a good home: HP 100E Freq. Standard

Ellen its free. Regards Paul WB8TSL On Mon, Jun 5, 2017 at 7:38 PM, Ellen Franke wrote: > I am interested, very interested. How much? Do you accept PayPal? > > John Franke > 4500 Ibis Ct > Portsmouth, VA 23703 > > > On June 5, 2017 at 2:48 PM Neal MacDonald wrote: > > > > > > I have an HP 100E

Re: [time-nuts] MIT flea meet-up for time-nuts

Eric it was good to meet you and your wife at MIT. My wife and I were digging through Berry's parts. It was a pretty nice MIT. Though as they say the pick-ns are getting thinner. Regards Paul WB8TSL On Fri, May 19, 2017 at 1:31 PM, Eric Scace wrote: > The MIT Flea

Re: [time-nuts] Free to a good home: HP 100E Freq. Standard

I am interested, very interested. How much? Do you accept PayPal? John Franke 4500 Ibis Ct Portsmouth, VA 23703 > On June 5, 2017 at 2:48 PM Neal MacDonald wrote: > > > I have an HP 100E Frequency Standard that I found at a garage sale and bought > on a whim a while ago. I don’t have much use f

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

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

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

Chris wrote: Today all you need is a reliable way to measure the error between the crystals' current temperature and the set point. That's all that's ever been needed. But it is devilishly difficult to measure the actual quartz temperature, or even to find a good proxy that is easier to me

Re: [time-nuts] Free to a good home: HP 100E Freq. Standard

I'd love to have one but yes, shipping from D.C. to CA would be at least $100 and more if you wanted it to arrive in one piece. This one should go to an enthusiast in the mid-east (is that the correct term for the middle Atlantic states?). Jeremy N6WFO On Mon, Jun 5, 2017 at 4:58 PM Bob kb8tq

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

Hi That paper is the basis for the MCXO. It is an interesting way to do a TCXO. The drift between the two modes makes it a difficult thing to master in an OCXO. Plating a pair of electrodes (one pair per mode) is also an approach that has been tried. Bob > On Jun 5, 2017, at 7:20 PM, Chris Ca

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

Hi For further info on just why the crystal temperature is such a crazy thing to track, check out Rick’s paper. At first glance it *seems* like it’s a trivial thing. In reality, gradients are a very big deal. Bob > On Jun 5, 2017, at 6:38 PM, Charles Steinmetz wrote: > > Chris wrote: > >> T

Re: [time-nuts] Free to a good home: HP 100E Freq. Standard

Hi If there are no takers from the rest of the list, I’ll drive down and pick it up. Shipping a beast like this is a royal pain. Let’s wait a couple weeks and see if anybody else wants it. Bob > On Jun 5, 2017, at 2:48 PM, Neal MacDonald wrote: > > I have an HP 100E Frequency Standard that I

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

On Mon, June 5, 2017 5:38 pm, Charles Steinmetz wrote: > Some years ago, I consulted for a research group that was using a number > of non-contact technologies to measure the temperature of oscillating > quartz crystals. In most cases what you really care about is the stability of the frequency, a

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

On Mon, Jun 5, 2017 at 3:38 PM, Charles Steinmetz wrote: > Chris wrote: > > Today all you need is a reliable way to measure the error >> between the crystals' current temperature and the set point. >> > > That's all that's ever been needed. But it is devilishly difficult to > measure the actual

[time-nuts] PPS sync

Yes, that is the sawtooth correction parameter. If a receiver reports the sawtooth correction value, but not a GPSDO EFC dac setting, Heather plots the sawtooth value as the GD plot and shows it where the DAC value is normally shown. Sawtooth values are seldom simple ramps. They represent t

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Additional info/papers on Thermistor stability: http://www.digikey.com/en/pdf/u/us-sensor/us-sensor-stability-long-term-aging https://www.thermistor.com/sites/default/files/specsheets/T150-Series-Stability.pdf https://www.vishay.com/docs/49498/ntcs-e3-smt_vmn-pt0283.pdf >From LIGO: http://www.

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Here's a NIST paper on Thermistor stability: http://nvlpubs.nist.gov/nistpubs/jres/83/jresv83n3p247_A1b.pdf Bruce > > On 06 June 2017 at 01:45 Bob kb8tq wrote: > > Hi > > Well, as part of the process of designing them into OCXO’s you do indeed > check their long term stability.

[time-nuts] Free to a good home: HP 100E Freq. Standard

I have an HP 100E Frequency Standard that I found at a garage sale and bought on a whim a while ago. I don’t have much use for it, but it seems like a shame to toss it so I figured I’d offer it up here. It’s yours for free, just pay shipping costs from the DC area. I was told by the original own

Re: [time-nuts] PPS sync

Chris, I think you are onto something. Running Lady Heather on this unit I see a line under “receiver” with the term “SawT” and a parameter of 24ns. So if we combine this information with what you teach below, it’s starting to look like maybe the M12 unit is doing something different than the

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

In message <20170605133013.526e8505158e68b6a8091...@kinali.ch>, Attila Kinali w rites: >> Where do digital sensors (e.g. ds1820 and some more recent parts from TI) >> fit into this ? > >AFAIK, these are all band-gap temperature sensors. The Ds1820 is based on the frequency difference be

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

Look at the dates on the uses of these exotic temperature controllers. Organic compounds and positive temp coefficients and so on. All these were used before the current era. Today all you need is a reliable way to measure the error between the crystals' current temperature and the set point. Th

Re: [time-nuts] PPS sync

I did not finish the sawtooth explanation. One of the units is designed such that the PPS is always on the raising edge of an internal 10MHz clock. If the 10MHz clock were perfect this means the maximum error is 1/2 cycle. The software in the GPS choose site best edge to minimize error. the

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

Yes, Agree. I wrote tin the first post that "for your use a resistive heater would be better" But everything else, I'd do over. Drill the aluminum block and use thermal epoxy to hold the sensor in place. Use a vacuum insulated mug or bowl for a cover and let a micro controller run a PID loop

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi Well, as part of the process of designing them into OCXO’s you do indeed check their long term stability. The test is done in an indirect fashion so you only come up with a “it’s below the limit” sort of number. The typical process involves running a group of OCXO’s on turn to check the fre

Re: [time-nuts] PPS sync

It was off 7.5KM, that’s a little beyond groggy, no? More like a trip to Vegas. I’ll let it rerun the survey and see if it gets closer. > On Jun 4, 2017, at 9:50 PM, Mark Sims wrote: > > Be careful when using one unit's location to set a different model's > location... particularly the altit

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi, guys I have been following time nuts and volt nuts for some time out of interest and fascination. Although my personal backyard hobby is more along a volt nuts line, the two worlds often collide - like in this discussion of temperature sensors, and in particular their long term stability. NT

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

Wax is also used for thermostatic valves in engine cooling systems and domestic heating systems. On Mon, Jun 5, 2017 at 1:13 PM, Tim Shoppa wrote: > Here is a national new-technology of the art crystal oven from 1956: > > http://tf.boulder.nist.gov/general/pdf/1642.pdf > > Using the phase change

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

On 6/4/17 10:01 PM, Chris Albertson wrote: Voltage is proportional to the product of resistance and absolute temperature. As an experiment place a voltage across a high value resister like say one 1M raise the volts until you are near the limit of the resister and connect it via a coupler cada

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

Here is a national new-technology of the art crystal oven from 1956: http://tf.boulder.nist.gov/general/pdf/1642.pdf Using the phase change properties of p-dibromobenzene it keeps temperature constant to 0.01C. It notes other organic compounds can be used for different temperature ranges. Did

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi > On Jun 5, 2017, at 7:30 AM, Attila Kinali wrote: > > On Mon, 5 Jun 2017 01:18:59 +0100 > Adrian Godwin wrote: > >> Where do digital sensors (e.g. ds1820 and some more recent parts from TI) >> fit into this ? > > AFAIK, these are all band-gap temperature sensors. But unlike a discrete > s

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

On Mon, 5 Jun 2017 01:18:59 +0100 Adrian Godwin wrote: > Where do digital sensors (e.g. ds1820 and some more recent parts from TI) > fit into this ? AFAIK, these are all band-gap temperature sensors. But unlike a discrete sensor, you have the problem that they only contain a low resolution ADC o

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

Hi The posistor approach to heating a crystal was originally pioneered in Russia. Morion was building vacuum insulated / PTC controlled OCXO’s long before the PTC parts started showing up more generally in the 1970’s. Bob > On Jun 5, 2017, at 4:35 AM, Ulf Kylenfall via time-nuts > wrote: >

Re: [time-nuts] Temperature sensors and quartz crystals (was: HP5061B Versus HP5071 Cesium Line Frequencies)

Hi If your objective is a resolution of < 0.001 C at something < 1 second, the current crop of digital sensors don’t quite do what you need to do. They are a terrific way to do wide range measurements that might feed into some sort of correction algorithm. A conventional thermistor bridge fa

[time-nuts] PPS sync

Be careful when using one unit's location to set a different model's location... particularly the altitude. Some devices report altitude in MSL, others in AGL... and different units may use different models for the ellipsoid. You are always better off using coordinates generated by the par

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

There's a few 'OCXO' designs out there, I'm not qualified to comment on the timenutty quality of them but someone else mentioned Hans Summers offerings and I would offer Roman Black's simple design (if it's not been mentioned already): http://www.romanblack.com/xoven.htm I've no idea if it's usef

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

On Sun, 4 Jun 2017 22:01:45 -0700 Chris Albertson wrote: > Voltage is proportional to the product of resistance and absolute > temperature. As an experiment place a voltage across a high value > resister like say one 1M raise the volts until you are near the limit of > the resister and connect

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

Not quite as simple as the PTC, an alternative may be: http://shop.kuhne-electronic.de/kuhne/en/shop/accessoires/crystal-heater/Precision+crystal+heater+40%C2%B0+QH40A/?card=724 No it probably doesn't hold the crystal at it's optimum turn over temperature, but it will keep the temperature of a cr

[time-nuts] Poor man's oven

  The Crystal heater clip wasa Murata "Posistor" soldered onto a clipand they were marketed by Murata. I once purchased a small amount of theseand used them as "poor man's ovens". Although not perfect by far, they did theirjob and kept my UHF gear stable. Murata dropped that product many yearsago