repair SRO-100 rubidium lamp - Page 1
Forum section: electronics / repair

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 12, 2019, 02:47:06 pm
content: today I tear down a fault SRO-100 Rubidium Oscillator, found the lamp can not be lit, all circult and MRF160 is OK, then I dismounted lamp, as the picture. seems the rubidium drop was splashed, use the hot gun to gather the small point, fixed;btw, never found the Rubidium lamp is leaked.

author: MadTux
author_rank: Frequent Contributor
timestamp: May 12, 2019, 05:38:26 pm
content: These thingies usually need a certain temperature to operate, so that there is enough Rb vapor pressure in the bulb for the plasma to ignite. Other than that, it needs like 100-150MHz of RF on that coil.So build an LC oscillator with it and feed it enough power. Then heat it carefully with a heat gun. With enough of RF power and at the right temperature, the bulb should light up and glow in a purplish color.

author: DaJMasta
author_rank: Super Contributor
timestamp: May 12, 2019, 07:57:26 pm
content: Yeah, definitely requires heat for normal operation, I think the right ballpark is 70-80C for the lamp itself. Can't see from the pictures, but it also does degrade over time, I don't remember the exact mechanism but I believe material gets deposited on the glass as it ages and eventually stops working, depending on the age/usage, that could be another issue.I'd recommend looking at the SRS PRS-10 documentation, they go into some detail the mechanisms that their design uses as well as the theory of operation of the lamp and "physics package" as a whole, plus they mention some temperatures and things.

author: Gyro
author_rank: Super Contributor
timestamp: May 12, 2019, 08:29:29 pm
content: The repair of Rubidium lamps by returning the metallic Rubidium to the 'pinch' has come up in the past. There is a a write-up or video somewhere. For an electrodeless discharge lamp capsule, short of rupture, this is the only possible failure mode.

author: texaspyro
author_rank: Super Contributor
timestamp: May 13, 2019, 02:50:13 am
content: BTW, Lady Heather v6.xx supports the SRO-100...

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 13, 2019, 04:58:04 pm
content: Quote from: DaJMasta on May 12, 2019, 07:57:26 pmthe problem is shock, Rubidium maybe is liquid if the temp is more the 40C, then you shock it, may cause the splash.

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 13, 2019, 04:59:47 pm
content: I will try it tomorrow, I ever use 6.14b to test PRS10, seems the status only display to AD9, no AD10-AD18

author: texaspyro
author_rank: Super Contributor
timestamp: May 13, 2019, 05:39:24 pm
content: Quote from: testpoint1 on May 13, 2019, 04:59:47 pmThats all that will fit on the main screen. If you turn off the digital clock (GZ) you will get more room. Or use ZD to show everything on a zoomed screen. On the next version, clicking on the info table will also show all the data.

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 14, 2019, 08:27:35 am
content: Quote from: texaspyro on May 13, 2019, 02:50:13 amyes, it supportdo you know how to add the DDS option for the SRO-100, seems one SOP-28 chip is missing.

author: texaspyro
author_rank: Super Contributor
timestamp: May 14, 2019, 05:58:14 pm
content: Quote from: testpoint1 on May 14, 2019, 08:27:35 amNope...BTW, Heather can do a screen dump to a .GIF (or .BMP) file with the WS command. Also by clicking on the second column of numbers at the top of the screen or pressing the '\' key.

author: jpb
author_rank: Super Contributor
timestamp: May 14, 2019, 08:06:52 pm
content: This reference describes reviving Rubidium lamps:http://n4iqt.com/efratom8084008/eeratom_model_frs_lamp_assembly_repair.pdfAnd this is a general repair guide:https://www.changpuak.ch/electronics/ocxo/Efratom_LPRO_101_Repair_Guide.pdf

author: testpoint1
author_rank: Frequent Contributor
timestamp: May 15, 2019, 01:57:05 am
content: Quote from: jpb on May 14, 2019, 08:06:52 pmthanks, to the LPRO 101, I already studied several months, all the life end of key component will concern the accuracy were not point out by the document.

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 18, 2019, 03:26:58 pm
content: Quote from: texaspyro on May 13, 2019, 05:39:24 pmyes, it does.