FS: Datum Efratom LPRO 101 Rubidium Frequency Standard, calibrated, with PCB kit

[testpoint1]

109 usd, details link:  https://www.ebay.com/itm/173839478443

Frequency Accuracy At Shipment: ± 5E-11 (25°C), please check the attached test diagram(working 2 hours);



LPRO 101 clock is a classic product in the field, the most valuable kit for the electronic fans, even the others try to copy it, just like FE5682A,  XHTF10034 etc, you can compare the KPI (aging tolerance of frequency, phase noise, MTBF etc), since the LPRO using the military class component in the key point, the KPI is best, btw, do not touch the XHTF seris (chinese made), the return rate may high since the clock's working temperature more then 70 degree (celsius).

 will use the "ePacket" ship to following countries (can track, if not in the list, sorry can not send):



United States,Ukraine,Canada,United Kingdom,Kazakhstan,New Zealand,Japan,Vietnam,Taiwan,

Hong Kong,Thailand,Indonesia,Korea,Malaysia,Singapore,Saudi Arabia,Israel,Spain,France,

Germany,Sweden,Norway,Portugal,Turkey,Austria,Belgium,Switzerland,Denmark,Hungary,Italy,

Luxembourg,Netherlands,Poland,Greece,Finland,Ireland,Mexico,Brazil;

updated 1/June/2019:
we designed a dedicated PCB board, install of previous board, now no need do any soldering, already installed all components:

[beanflying]

Mmmm Do I 'need' one 

Just for your own information if I search for your item on ebay.com.au this item doesn't show up in a search using "Efratom LPRO 101 Rubidium" or any of the words  Shows up fine on ebay.com so you might like to look at your shipping settings? Not sure if it is similar on other ebay's around the world?

Any idea how long before you will have a complete unit available?

[DC1MC]

Do you do combined shipping for all 3 (generator + radiator + power supply) and how much it will cost a full kit ?
Also for Germany, and Europe in general, you can drop the power supply cable to reduce size/weight, it's useless here.

 Thanks,
 DC1MC

[jeremy]

Um, this listing says both:

- Datum Efratom LPRO 101 Rubidium Frequency Standard, calibrated, with PCB install kit;
- please be aware if the LPRO 101 is not calibrated, can NOT use for accurate standard since its 10 years tolerance is 1E-9;

So which one is it?

[testpoint1]

the power cable is very short, very light, if combine the 3 kits, the shipping cost almost same.

[testpoint1]

all calibrated before delivery.

[DC1MC]

the power cable is very short, very light, if combine the 3 kits, the shipping cost almost same.

Almost same like 3xshipping or almost same like 1x shipping ?

[nctnico]

Note that these telecom Rubidium clocks still have a lot of phase noise on both the 10MHz and 1PPS output. For metrology grade-ish measurements you'll need to add an extra oscillator to clean the 10MHz and add a circuit to derive the 1PPS from the 10MHz directly.

[Kosmic]

Interesting. Do I need one ? 

Is the heatsink mandatory ?

Edit: I should have read the listing. For long run (>30 min) you need some cooling.

[Kosmic]

The 10 years tolerance is probably since last calibration. If you calibrate on a regular basis with a gpsdo it's probably not a problem.

[Kosmic]

OK can't resist anymore, just bought one. 

[testpoint1]

GPSDO based on OCXO is no enough accuracy to calibrate a Rubidium clock, you can use a Cs clock or a new Rubidium clock (with GPSDO 1pps signal) to calibrate it.

[testpoint1]

the power cable is very short, very light, if combine the 3 kits, the shipping cost almost same.

Almost same like 3xshipping or almost same like 1x shipping ?

the shipping cost is based on the weight, the basic weight is from 0 to 5 grams (different country may vary). so I said almost same.

[testpoint1]

Note that these telecom Rubidium clocks still have a lot of phase noise on both the 10MHz and 1PPS output. For metrology grade-ish measurements you'll need to add an extra oscillator to clean the 10MHz and add a circuit to derive the 1PPS from the 10MHz directly.

I ever tested many brands atomic clock, and tear down more than 100 units, you can check the circuit and component then will know why the phase noise for some brand is quite high.

[Kosmic]

GPSDO based on OCXO is no enough accuracy to calibrate a Rubidium clock, you can use a Cs clock or a new Rubidium clock (with GPSDO 1pps signal) to calibrate it.

You are right. I mean you could calibrate your rubidium clock with a gpsdo but it's going to be as good as your gpsdo. Not better.

So the question is, with what did you calibrate the rubidium clock you are selling ?

[Dr. Frank]

 Folks,
Of course you can calibrate an Rb standard down to 10^-11, using a GPSDO, but you have to use long averaging times, or the appropriate method.
Just look at the Allan deviations of GPSDO, and then you'll see that at about 1000.. 10000 sec, you'll reach that stability.
After 2h warm up, no Rb will be stable enough to be calibrated to 5x10^-11. It takes 1..2days at least.
And yes, a sufficient heat sink is mandatory..see most manuals of RB standards.

Frank

[testpoint1]

Mmmm Do I 'need' one 

Just for your own information if I search for your item on ebay.com.au this item doesn't show up in a search using "Efratom LPRO 101 Rubidium" or any of the words  Shows up fine on ebay.com so you might like to look at your shipping settings? Not sure if it is similar on other ebay's around the world?

Any idea how long before you will have a complete unit available?

the complete kit will be ready within 2 weeks, now is sample machine.

[testpoint1]

Folks,
Of course you can calibrate an Rb standard down to 10^-11, using a GPSDO, but you have to use long averaging times, or the appropriate method.
Just look at the Allan deviations of GPSDO, and then you'll see that at about 1000.. 10000 sec, you'll reach that stability.
After 2h warm up, no Rb will be stable enough to be calibrated to 5x10^-11. It takes 1..2days at least.
And yes, a sufficient heat sink is mandatory..see most manuals of RB standards.

Frank

the reference clock always in power on, I compared the 2 hours log and 2 days log of the LPRO-101, a little diff

[testpoint1]

GPSDO based on OCXO is no enough accuracy to calibrate a Rubidium clock, you can use a Cs clock or a new Rubidium clock (with GPSDO 1pps signal) to calibrate it.

You are right. I mean you could calibrate your rubidium clock with a gpsdo but it's going to be as good as your gpsdo. Not better.

So the question is, with what did you calibrate the rubidium clock you are selling ?

a new  rubidium clock with GPSDO (internal is LEA 8T GPS module), power on more than one week.

[Mr. Scram]

the complete kit will be ready within 2 weeks, now is sample machine.

I appreciate that it has a proper front, not one of those cheap looking PCB front panels.

[testpoint1]

the complete kit will be ready within 2 weeks, now is sample machine.

I appreciate that it has a proper front, not one of those cheap looking PCB front panels.

the house just made by factory (even the screw is stainless), I designed it, the purpose is for electronic fan get a professional tool.

[testpoint1]

Note that these telecom Rubidium clocks still have a lot of phase noise on both the 10MHz and 1PPS output. For metrology grade-ish measurements you'll need to add an extra oscillator to clean the 10MHz and add a circuit to derive the 1PPS from the 10MHz directly.

I ever tested many brands atomic clock, and tear down more than 100 units, you can check the circuit and component then will know why the phase noise for some brand is quite high.

can you show phase noise plot?

I am sorry since there is no 1Hz RBW concept in wireless communication field, so I never prepared such analyzer to test.

[testpoint1]

If complete kit is ready. How much cost addition to the $99?

if the house is ready, the naked LPRO-101 will not sell any more, and the price will be 1XX USD

[testpoint1]

Folks,
Of course you can calibrate an Rb standard down to 10^-11, using a GPSDO, but you have to use long averaging times, or the appropriate method.
Just look at the Allan deviations of GPSDO, and then you'll see that at about 1000.. 10000 sec, you'll reach that stability.
After 2h warm up, no Rb will be stable enough to be calibrated to 5x10^-11. It takes 1..2days at least.
And yes, a sufficient heat sink is mandatory..see most manuals of RB standards.

Frank

the LPRO-101 uses SMD device, no need much more hot time, you can check its manual within internet.

[beanflying]

If complete kit is ready. How much cost addition to the $99?

if the house is ready, the naked LPRO-101 will not sell any more, and the price will be 1XX USD

Is that $1.xx or $100 or $1??  Consider me likely interested in 2 weeks