ATTN Time Nuts: eBay [UK] - Datum PR50 Cesium Beam Primary Reference Source - Page 1
Forum section: electronics / general

author: Towger
author_rank: Super Contributor
timestamp: September 30, 2017, 06:41:14 am
content: This item which I assume is a Cesium Reference by Datum (RIP) appeared last night:http://www.ebay.co.uk/itm/Datum-PR50-Cesium-Beam-Primary-Reference-Source/162691173592eBay auction: #162691173592But that is not all!The seller also has a Rubidium Clock, but does not know it:"Does it also have a Stratum Clock as well?http://www.ebay.co.uk/itm/Datum-3800E-Controllers/152722392403eBay auction: #152722392403

author: grumpydoc
author_rank: Super Contributor
timestamp: September 30, 2017, 07:08:59 am
content: I amsoglad I don't have the space (or the time) to bid on this.Presumably the two units were used together with the rubidium disciplined by the caesium reference.Can't quickly find a manual for the PRS 50 - there is one for the PRS 45, which looks similar, herehttp://www1.symmetricom.com/media/files/support/productmanual/man-prs-45.pdfPresumably he can't test it since it needs 2x 48V DC supplies.EDIT: Helps if I use the correct search string -http://www1.symmetricom.com/media/files/support/productmanual/man-prs-50.pdf

author: awallin
author_rank: Frequent Contributor
timestamp: September 30, 2017, 07:55:01 am
content: edit: new link:http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=02_GPS_Timing/Symmetricom12-year warranty on the beam tube...

author: grumpydoc
author_rank: Super Contributor
timestamp: September 30, 2017, 08:39:44 am
content: Quote from: awallin on September 30, 2017, 07:55:01 amAbove link dead - well, it just drops on the ko4bb main page

author: tggzzz
author_rank: Super Contributor
timestamp: October 02, 2017, 04:11:28 pm
content: Phew; that was a close shave. Someone snipedfarmore than I was prepared to pay.

author: Towger
author_rank: Super Contributor
timestamp: October 02, 2017, 04:14:45 pm
content: So who got them? £205 and £116 respectively, so not a bad price if you'r into these things.

author: TheSteve
author_rank: Unknown
timestamp: October 02, 2017, 04:17:15 pm
content: A great price indeed, even for parts.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: October 02, 2017, 04:29:21 pm
content: I won the PRS50 Caesium but not the Rb unit as the seller stops buyers from buying more that 1 item at a time. Really hacked off as I was willing to pay more than the winning bid.If it arrives I will keep everyone who is interested informed in a new topic.CheersPhilP.S. does this make me a time nut?

author: guido
author_rank: Regular Contributor
timestamp: October 02, 2017, 05:34:30 pm
content: Congrats. There is a threadhttps://www.eevblog.com/forum/metrology/no-luck-on-my-first-attempt-at-acquiring-a-cesium-frequency-standard/175/in the metrology section, you fit right inSo now it is time to arrange for a PC with RS232, a null modem cable and the monitor3 software (http://www.w2hx.com/x/Datum/PRS45A/). Too bad you did not get the other unit, but i think most cards were useless telecoms stuff.Edit, the doc that comes with the monitor3 software does not state that the 50 is supported (45 is). The 50 manual (KO4BB site) mentions monitor. The 45 manual monitor2. So you will have to try.The 45 manual does not mention the 12 year warranty. Just one year in the warranty section. Just like the 50 manual. Somewhere else the 12 years on the tube is mentioned. And 2 (...) years on the electronics. I think 12 years is for a regular tube. A high performance one does not last that long i read somewhere. If monitor works, you can see from the parameters what you have. See the thread above.

author: Towger
author_rank: Super Contributor
timestamp: October 02, 2017, 06:45:13 pm
content: Congratulations. Can't wait to see it in detail. It will be interesting to see how runs, the manual talks about running it for half an hour every 6 months. There is a sticker on the inside photo, which appear to date it from 1999.

author: grumpydoc
author_rank: Super Contributor
timestamp: October 02, 2017, 07:03:34 pm
content: Quote from: Oldtestgear on October 02, 2017, 04:29:21 pmOh, that's a pain as they clearly needed to stay together.Glad I did not bid now (despite my earlier comment I considered it).

author: Towger
author_rank: Super Contributor
timestamp: October 02, 2017, 07:42:42 pm
content: Quote from: grumpydoc on October 02, 2017, 07:03:34 pmI was tempted with the Rubidium unit. Less lightly to have customs 'difficulties'.But, I spent too much on a for parts 'does not light up' HF amplifier. Looking at the internal photo on a proper computer it looks as if someone 'had a go' on all 4 of the RF transistors, splattered burnt flux allover the place. A what the hell moment!

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 04, 2017, 09:41:22 am
content: I am SO glad I didn't see this thread.That Cs reference looks so fun and we would have ended up bidding against each other.

author: testpoint
author_rank: Regular Contributor
timestamp: October 08, 2017, 03:11:52 am
content: the CS clock's life may reached. please check it.

author: Oldtestgear
author_rank: Regular Contributor
timestamp: October 08, 2017, 04:47:04 pm
content: The Cs clock may well be time expired but I have to actually get it before I can check. Looks as if I should get it on Tuesday 10th with a bit of luck. Must admit that this is one win that I am very anxious to get my hands on. Thanks for the warning though.Phil

author: Oldtestgear
author_rank: Regular Contributor
timestamp: October 10, 2017, 05:21:37 pm
content: Arrived today. Really badly packed. I have also acquired a Kvarz hydrogen maser today as well. I started a new post about both if anyone is interested.Thanks for the positive comments.Phil

author: Towger
author_rank: Super Contributor
timestamp: October 10, 2017, 08:29:18 pm
content: The manual has full instructions on how to transport it and all the required paperwork.