PDP 11 gear finally moved
tothwolf at concentric.net
Mon Jul 20 21:03:59 CDT 2015
On Mon, 20 Jul 2015, Rich Alderson wrote:
> On Sat, 18 Jul 2015, Peter Coghlan wrote:
>> Rich Alderson <RichA at LivingComputerMuseum.org> wrote:
>>>> It is generally a good idea to re-form electrolytic capacitors in
>>>> power supplies, and to bench check the power supplies (under some
>>>> kind of load) before actually applying power to the whole unit.
>>> It is always a good idea to replace electrolytic capacitors in power
>>> supplies. The rest of the advice is sound.
>> Can you please clarify if this statement represents the policy of the
>> Living Computer Museum or is it something more personal? Perhaps some
>> qualification or a re-phrasing would be useful as it does not appear to
>> make sense as it stands?
> This is the policy of Living Computer Museum. It is based on the
> cumulative experience of multiple very senior electrical engineers
> doing restorations here, in conjunction with industry white papers with
> tables of decay rates for the aluminum electrolytics that indicate that,
> *no matter what*, they lose capacitance over time, until c. 14 years
> from manufacturer date they are at 10% of rating.
>> I think you may have seen or participated in some of the many
>> discussions we have had on this topic on this list? In light of these
>> discussions, I find it hard to see how a categorical statement such as
>> this one could be justified.
> Since the proponents of this practice make categorical statements with
> no evidence that they want to listen to reasoned explanations, I long
> ago gave over trying to convince them, and simply respond when someone
> makes a statement to a newbie which will result in frustration and
> failure for the unfortunate recipient of this advice.
Do you happen to have a list of whitepapers and/or links on hand? I too am
getting tired of repeating the same thing over and over and compiling this
sort of information in a single location might be helpful. Buried in my
own archives I have quite a few papers and datasheets in pdf format, but
they are all mixed in with everything else so finding them would be quite
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