FS: Datum Efratom LPRO 101 Rubidium Frequency Standard, calibrated, with PCB kit - Page 1
Forum section: electronics / general

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 05:45:00 am
content: 109 usd, details link:https://www.ebay.com/itm/173839478443Frequency 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:

author: beanflying
author_rank: Super Contributor
timestamp: March 17, 2019, 06:26:10 am
content: Mmmm Do I 'need' oneJust 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 wordsShows 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?

author: DC1MC
author_rank: Super Contributor
timestamp: March 17, 2019, 07:19:52 am
content: 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

author: jeremy
author_rank: Super Contributor
timestamp: March 17, 2019, 10:00:22 am
content: Um, this listing says both:- Datum Efratom LPRO 101 Rubidium Frequency Standard,calibrated, with PCB install kit;- please be aware if the LPRO 101 isnot calibrated, can NOT use for accurate standard since its 10 years tolerance is 1E-9;So which one is it?

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 12:02:04 pm
content: the power cable is very short, very light, if combine the 3 kits, the shipping cost almost same.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 12:02:55 pm
content: all calibrated before delivery.

author: DC1MC
author_rank: Super Contributor
timestamp: March 17, 2019, 02:15:49 pm
content: Quote from: testpoint1 on March 17, 2019, 12:02:04 pmAlmost same like 3xshipping or almost same like 1x shipping ?

author: nctnico
author_rank: Super Contributor
timestamp: March 17, 2019, 02:30:18 pm
content: 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.

author: Kosmic
author_rank: Super Contributor
timestamp: March 17, 2019, 04:18:35 pm
content: 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.

author: Kosmic
author_rank: Super Contributor
timestamp: March 17, 2019, 04:20:32 pm
content: 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.

author: Kosmic
author_rank: Super Contributor
timestamp: March 17, 2019, 05:43:33 pm
content: OK can't resist anymore, just bought one.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 06:05:19 pm
content: 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.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 06:08:05 pm
content: Quote from: DC1MC on March 17, 2019, 02:15:49 pmthe 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.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 17, 2019, 06:11:26 pm
content: Quote from: nctnico on March 17, 2019, 02:30:18 pmI 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.

author: Kosmic
author_rank: Super Contributor
timestamp: March 17, 2019, 06:36:35 pm
content: Quote from: testpoint1 on March 17, 2019, 06:05:19 pmYou 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 ?

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 17, 2019, 10:18:39 pm
content: 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

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 04:02:02 am
content: Quote from: beanflying on March 17, 2019, 06:26:10 amthe complete kit will be ready within 2 weeks, now is sample machine.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 04:05:09 am
content: Quote from: Dr. Frank on March 17, 2019, 10:18:39 pmthe reference clock always in power on, I compared the 2 hours log and 2 days log of the LPRO-101, a little diff

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 04:07:31 am
content: Quote from: Kosmic on March 17, 2019, 06:36:35 pma new rubidium clock with GPSDO (internal is LEA 8T GPS module), power on more than one week.

author: Mr. Scram
author_rank: Super Contributor
timestamp: March 18, 2019, 04:50:25 am
content: Quote from: testpoint1 on March 18, 2019, 04:02:02 amI appreciate that it has a proper front, not one of those cheap looking PCB front panels.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 08:12:28 am
content: Quote from: Mr. Scram on March 18, 2019, 04:50:25 amthe house just made by factory (even the screw is stainless), I designed it, the purpose is for electronic fan get a professional tool.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 08:48:48 am
content: Quote from: Mechatrommer on March 18, 2019, 04:33:37 amI am sorry since there is no 1Hz RBW concept in wireless communication field, so I never prepared such analyzer to test.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 10:05:34 am
content: Quote from: Mechatrommer on March 18, 2019, 08:55:22 amif the house is ready, the naked LPRO-101 will not sell any more, and the price will be 1XX USD

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 18, 2019, 10:08:41 am
content: Quote from: Dr. Frank on March 17, 2019, 10:18:39 pmthe LPRO-101 uses SMD device, no need much more hot time, you can check its manual within internet.

author: beanflying
author_rank: Super Contributor
timestamp: March 18, 2019, 11:47:24 am
content: Quote from: testpoint1 on March 18, 2019, 10:05:34 amIs that $1.xx or $100 or $1??Consider me likely interested in 2 weeks

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 21, 2019, 05:23:30 pm
content: Zeeman Effect of Rubidium

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 22, 2019, 12:25:55 am
content: today will ship it since I need time to calibrate it, I also can give you the GPSDO (with OXCO) data to you, you can compare the Allan Deviation.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 25, 2019, 09:39:08 am
content: Quote from: Mechatrommer on March 21, 2019, 11:49:43 pmtest a GPSDO (buy from Internet), do a comparison between calibrated LPRO 101 and it. there is no mean to compare a OXCO to a Rubidium clock, actually, both of them hot 2 hours:

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 25, 2019, 11:19:07 am
content: Quote from: Mechatrommer on March 25, 2019, 10:38:19 amit is not yours, your LPRO already deliverred, according my experience, all the LPRO 101, 20 years working time, never calibrated, show the worst value is 10.000 000 011 xx MHz, better than the GPSDO

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 25, 2019, 04:02:01 pm
content: Quote from: Mechatrommer on March 25, 2019, 12:23:44 pmall the problem is heating problem of the Resistor, if you install a certain heat sink for the LPRO, it is not easy to die, any way, Rubidium lamp and cell is no problem for your next 10 years.

author: Kosmic
author_rank: Super Contributor
timestamp: March 27, 2019, 03:22:55 am
content: Received my unit today. It's working perfectly. Thanks testpoint1 !

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 27, 2019, 02:35:28 pm
content: Quote from: Kosmic on March 27, 2019, 03:22:55 amgood, I try to increase the frequency accuracy from 5E-9 (like GPSDO etc.) to 5E-11 for the world's electronic amateur. hope you enjoy it.

author: testpoint1
author_rank: Frequent Contributor
timestamp: March 31, 2019, 05:32:03 am
content: after several years, one company made a product, FE-5682A (interface compatible with LPRO-101), you can compare the stability with LPRO-101.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 06, 2019, 02:55:19 pm
content: what is the purpose for the LPRO 101 using?

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 06, 2019, 05:24:47 pm
content: Quote from: Mechatrommer on April 05, 2019, 04:51:10 pmQuote from: testpoint1 on April 06, 2019, 02:55:19 pm10MHz reference, what else?later if i have time, i'll produce 100MHz and 1GHz reference as well from it using PLL or something.btw, here's my (attached) reading of the signal when locked...1) DS1054Z (into 10Mohm Hi-Z probe)2) KC901V 10MHz reading (off at 9.999333 MHz)3) KC901V 100KHz Span4) KC901V 1MHz Span5) KC901V 10MHz Span6) KC901V 100MHz Span (10dB ref, 30KHz RBW)advice welcomed fwiw...

author: all_repair
author_rank: Frequent Contributor
timestamp: April 07, 2019, 03:15:20 pm
content: "the complete kit will be ready within 2 weeks, now is sample machine"Is it ready?

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 08, 2019, 01:48:35 am
content: yes, ready, the 3 days' is a Chinese vacation, I will post it in ebay soon.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 09, 2019, 05:08:08 pm
content: Quote from: all_repair on April 07, 2019, 03:15:20 pmthe LPRO-101 with house version released, and the standalone version still keep, and have 2 slim 101 Rubidium clock (SLCR) to sell.

author: syau
author_rank: Frequent Contributor
timestamp: April 09, 2019, 05:28:25 pm
content: Quote from: testpoint1 on April 09, 2019, 05:08:08 pmOrder placed

author: Mr. Scram
author_rank: Super Contributor
timestamp: April 09, 2019, 08:25:32 pm
content: Quote from: beanflying on March 18, 2019, 11:47:24 amI'm not sure how confusion about the intended price could arise.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 10, 2019, 12:48:03 am
content: Quote from: syau on April 09, 2019, 05:28:25 pmthanks, will ship today, and the list is:https://www.ebay.com/itm/173868078573

author: all_repair
author_rank: Frequent Contributor
timestamp: April 10, 2019, 01:15:03 am
content: Quote from: syau on April 09, 2019, 05:28:25 pmMy order just in also. If come with calibration certificate shall be very niceNever mind if your lab is certified or not, as long as your reference is.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 10, 2019, 02:10:54 am
content: Quote from: all_repair on April 10, 2019, 01:15:03 amI try to calibrate it, maybe I move to US, can get the NIST certification

author: Mr. Scram
author_rank: Super Contributor
timestamp: April 11, 2019, 02:19:40 pm
content: Do I understand correctly the power supply needs to be bought separately? Can this be disciplined with a GPS later on, which would of course require some conversion?

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 12, 2019, 06:49:29 am
content: Quote from: Mr. Scram on April 11, 2019, 02:19:40 pmthis one is NOT a clock can be trained by GPS; yes, if you have no 24V power, you need to purchase it from me, I select the 24V power from several types, the power is small and stable, and cheap.

author: Towger
author_rank: Super Contributor
timestamp: April 12, 2019, 06:11:27 pm
content: I don't see why they can't be GPS disciplined. The the frequency can be adjusted by changing the voltage on pin 7 from the default of 2.5v, to between 0 to 5 volts. The manual covers this. The Lars GPSDO design from what my understanding would require little or no changes to do the job.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 13, 2019, 01:36:42 am
content: Quote from: Towger on April 12, 2019, 06:11:27 pmyes, the pin is for external fine tuning, same as internal, but, did you find any GPSDO output can connect the pin? you also need to design the PLL circuit then can use, try it.

author: testpoint1
author_rank: Frequent Contributor
timestamp: April 15, 2019, 06:36:03 am
content: if someone instrested in the GPSDO, FEI has one, I listed in here (power on 24 hours test it):https://www.ebay.com/itm/173873594220if someone need my CNT-90 counter, I also list it in my shop.

author: syau
author_rank: Frequent Contributor
timestamp: April 17, 2019, 03:58:17 pm
content: Quote from: testpoint1 on April 10, 2019, 12:48:03 amReceived the unit today. Will do some testing during weekend.

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 05, 2019, 02:23:55 am
content: I also use a SRS PRS10 (used) with GPS 1pps in (GPS is Ublox M8T) to verify my reference, no problem. next I will seek a Cesium clock.

author: syau
author_rank: Frequent Contributor
timestamp: May 05, 2019, 10:22:16 am
content: Quote from: testpoint1 on May 05, 2019, 02:23:55 amThe frequency is very accurateNote: 53310A clock by a GPSDO

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 06, 2019, 08:35:07 am
content: Quote from: syau on May 05, 2019, 10:22:16 amyour GPSDO may exists more tolerance than the LPRO, hehe, check it.

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 16, 2019, 08:42:34 am
content: I will release a smallest GPSDO soon, only 89 USD.

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 21, 2019, 09:13:55 am
content: if the country in the attached list, will use e-EMS ship it, the shipping price maybe add some.

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 01, 2019, 02:20:04 am
content: updated 1/June/2019:we designed a dedicated PCB board, install of previous board, now no need do any soldering, already installed all components, the new purchasing will use the board.add a fuse for the power supply, since there is no short circuit protection of LPRO 101, the factory think it is a part, you can install the protection circuit.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 02, 2019, 03:29:11 pm
content: currently testing my Advantest R3465 SA with LPRO101 signal. the LPRO101 cannot lock after long time. usually it will lock in about 15 minutes, it did lock for a moment and then not locked anymore (LED always ON), it still got hot on top, the bottom part (with light green paint) is on big heatsink. what should i do?

author: Towger
author_rank: Super Contributor
timestamp: June 02, 2019, 07:55:13 pm
content: AFAIK, you cannot drive a lock LED directly off the (BITE) output. As per the above boards. The manual says that requires a high impedance load.I believe these is a write-up on the model were the author says a low impedance stops it locking.

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 03, 2019, 01:19:06 am
content: Quote from: Mechatrommer on June 02, 2019, 03:29:11 pmif can not lock always, that means the clock is in malfunction, you may try to fix it.

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 03, 2019, 01:20:44 am
content: Quote from: Towger on June 02, 2019, 07:55:13 pmthe OP circuit can drive 5mA.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 03, 2019, 07:54:55 am
content: Quote from: testpoint1 on June 03, 2019, 01:19:06 amhow to open? no screw here(already opened, picture later). i dont want to change calibration, please advice which one not to touch.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 03, 2019, 09:12:41 am
content: ok opened, see attachment. where to start which one is suspect? is rubidium bulb suspect? how to open?

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 03, 2019, 02:53:41 pm
content: Quote from: Mechatrommer on June 03, 2019, 09:12:41 amgive me your email please, PM me.