xdevs.com Fluke 732A repair and modification pages

[perdrix]

Todd Micaleff put up a page on xdevs.com about the 732A.  However it seems incomplete.

The page is here: https://xdevs.com/fix/f732a/

Is this an error on the website, or a work in progress?

Thanks
Dave

[MisterDiodes]

Seems incomplete, but that unit has been discussed a lot on EEVblog.

Did you have a specific concern or question?

[TiN]

It is draft, work in progress.

[ManateeMafia]

Dave,

This is a work in progress. It actually there are two 732A. One had a drift issue after an extended power outage and the other was a new to me reference that needed to be checked out. It also appears to be drifting a lot. The new reference has drifted 1.5ppm in 6 months.
The pictures in the article are of the new to me reference. It currently has at least one problem. It will not enable the in cal LED. It worked when I first got it but now there is something wrong. The oven thermistor value seems steady.

I am making a few changes and then collecting data.

[Pipelie]

looking forward to reading it.

[perdrix]

I'm also interested to follow this, I've just replaced the electrolytic capacitors on the two regulator boards, but haven't touched the oven.

I did however change the jumpers on the calibration board as I was out of adjustment on the 10V potentiometer.

So far (it's been on a week since I did that) and it seems to have stabilised.  It was quite surprising to me how much it drifted initially - I had to adjust the 10V potentiometer about every day for the first few days to stay within 20uV of nominal.

I hope it will now settle down.

Dave

[alm]

Why would you adjust it every day? Would make more sense to just track the drift every day until it stabilizes, and only then adjust it? That would make it easier to track drift over time.

[perdrix]

Because it drifted a HUGE amount - milli-volts, not micro-volts, and I thought on each occasion "That must have stabilised now" - but I was wrong (until about day 5).

Dave

[TiN]

References that were cold for long time not rare to take weeks and months to get stable again. So I wouldn't even expect anything before first month. 
That is why all serious references are battery-backed, so even during shipping they can keep the power.