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
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,
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
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
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
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
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
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
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
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
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:
>
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
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,
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
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
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:
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
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
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
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
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.
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
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
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
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...
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.
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
>
>
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
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.
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
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
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
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
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
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
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
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
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
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