[time-nuts] RE. Re: WTS: Efratom PTB-100 Precision Timebase (Don at True-Cal)

[Andre]

Message: 2
Date: Wed, 11 Jul 2018 07:54:33 -0500
From: "Don at True-Cal" <t..>
To: "'Discussion of precise time and frequency measurement'"
        <time-nuts at lists.febo.com>
Subject: Re: [time-nuts] WTS: Efratom PTB-100 Precision Timebase
Message-ID: <015001d41916$5151d780$f3f58680$@gmail.com>
Content-Type: text/plain;       charset="us-ascii"

Thanks everyone for the insightful comments. I've been inspired by off-list
help to get this unit working primarily because of the quality of the
internal FRK. If nothing else, it has been a tremendous learning experience
and after numerous hours studying the manual and bench testing I find myself
knowing far more about optical pumping and Rb absorption lines than I
thought I ever wanted to know. I keep you posted if I have a breakthrough.

Regards,
Don

Incidentally it might be worth mentioning this.
Sulfur is a common breakdown of some encapsulants and atmospheric pollution can be a major
headache as H2S though in barely detectable quantities can erode the surface mount and
other components if they are exposed.
Do any of the components on your unit look even slightly tarnished, if so they will fail soon.
I've had this problem with Xbox handsets before possibly due to sulfur from handling.
Even a set of digital scales failed due to being in a shed next to PCB etching equipment.

I also noticed that sometimes a precision resistor will drift due to heat, as mentioned in the 
repair guides it can affect even parts near a heat source.

-Andre